Monday, 6 May 2019

Back To Basics

Back To Basics - First Time Out...

It looks like my blog posts are a bit like the proverbial busses.  Nothing for ages and then a couple at the same time!  The weather decided to cooperate this weekend, which is a first for a while in these parts.  We've recently moved house, so this was the first opportunity since unpacking all my gear after the move, to get out and see what the sky is like from the new back garden.
To put it bluntly, there's a big improvement.  Gone (so far) are the problems with neighbours security lights, light streaming across the garden from peoples kitchen windows and direct views of an LED street light.  The new garden is consistently in more darkness than the old place.  I've a feeling that future observing and imaging sessions in the new garden are going to be amazing!
So, to test things out and get a better feel for the place after the initial impressions, I set up the SBT (12" Dob) out the back garden, and started putting it through it's paces.
The weather had been very breezy with northerly winds and quite cold during the day, with occasional cloud cover passing through quickly.  As dusk approached, the wind dropped to almost nothing, and all horizons cleared to give uninterrupted views all around.

NGC 4485 and NGC 4490

Rather than start with some old favourites, before moving onto tougher targets, I decided to kick straight off with some new ticks, or, objects that I had not observed before.  This time of year is known by observers as Galaxy Season, because of the number of galaxies that can be observed throughout the night.  My first two are listed as Irregular Galaxies.  NGC 4485 (mag 12) and 4490 (mag 10) are very close to each other with 4490 (aka The Cocoon Galaxy) being the brighter.  They are found in the constellation of Canes Venatici.

Canes Venatici, located between Leo, Bootes and Ursa Major.
Credit: Stellarium  0.19.0
Both galaxies were visible in the same field of view when using the 32mm eyepiece, although the dimmer of the two was harder to make out due to it's size and magnitude.  The snippet below shows the two galaxies, although the image is quite poor.

The galaxies as shown in Stellarium.  Resolving 2 of the brighter stars in NGC 4485 was just about possible.
Credit: Stellarium 0.19.0

NGC 4631

Next on my tick list for the evening was this mag 9.6 galaxy.  Known also as the Whale Galaxy, it can be found in the constellation of Canes Venatici, although it is often mistaken for being in Coma Berenices.  It has neighbouring galaxy called The Hockey Stick, due to the apparent curved shape one side of the galaxy.
The location of The Whale Galaxy - NGC 4631.  Credit: Stellarium 0.19.0

The Whale Galaxy is an edge on spiral galaxy, and using the 32 mm Panaview eyepiece, I found that it easily extended 1/3 - 1/2 way across my field of view in the eyepiece.  I found that the galaxy was comparatively bright compare to some that I had viewed with the SBT, and this also helped bring out the very thin outer edges of the galaxy against the background of the moonless sky.

NGC 4631 - The Whale galaxy, shown in Stellarium next to the Crowbar (aka The Hockeystick) galaxy.  Credit: Stellarium 0.19.0
Note the neighbouring dwarf galaxy, NGC 4627.  I did not notice this galaxy on the night, only finding out about it when I was reading up on my main target the following day.  NGC 4627 is mag 13.0, so is probably on the extreme limit of what I can see using the SBT under my local sky.  However, now I know it is there, next time I observe NGC 4631, I will see if I can locate the dwarf galaxy too.

NGC 2903

It was time for me to move back across the other side of Leo, and onto my next target for the evening.  NGC 2903 can be found just in front of the head of Leo, the Lion.  At mag 9.6, this is a great alternative to hunt down, to the other galaxies around Leo.  It is a spiral galaxy, which apparently under very dark skies, shows some good structure in the arms of the spiral.  I easily found the galaxy, and could make out it's shape, although I was struggling to identify any true structure.
The location of NGC 2903, just at the head of Leo.  Credit: Stellarium 0.19.0

A potential target for imaging during this time of the year.  It's magnitude will mean a good couple of hours total exposure will be needed with my 80mm refractor to get anything close to the image above from Stellarium, but it is worthy of an attempt during a future AP session.  Credit: Stellarium 0.19.0
With the night moving on, and my eyes beginning to tire, it was time to swap out the 32mm panaview eyepiece, in favour of the 40mm.  This eyepiece is the largest on I have, and lets in the most amount of light.  Though the size means things can seem brighter, they also appear smaller because of the reduction in magnification.

M65 and M66

With a different eyepiece in the SBT, it was time to re-visit some familiar targets.  I moved over to the hind quarter of Leo, the home of the Leo Triplet.  These are a collection of galaxies, popular with imagers at this time of year.  Though they only show up as grey smudges of light, it's still nice to be able to revisit them.


Leaving the galaxies alone for the evening, the constellation of Hercules was just coming into view, past a tree on the side of the garden.  Hercules is home to some of the best examples of clusters in the northern hemisphere sky.  It's a really common target for observers to show to people new to astronomy, and it's easy to see why.  The cluster is large and bright, although on the night, I was struggling to resolve individual stars in the cluster.  That might have been due to the atmospheric conditions, or just tired eyes.  Nevertheless, it was nice to be able to try to identify the extent of the cluster.  


Staying in Hercules, and the last target for the evening, M92 is another cluster, which is often missed out.  If M13 is the default, go to cluster for new observers, M92 is the hidden gem.  Although hidden is perhaps a bit poor as a description.  Though not quite as large as it's near neighbour, M92 is every bit deserved of some eyepiece time.
On the night, the cluster seemed to have less bright stars throughout, appearing a little more uniformed in brightness, than M13.  It would be an interesting challenge to photograph these two clusters, but the focus would have to be absolutely spot on to do the image any justice.

It had not long gone midnight, and it was time to start packing up.  Tired eyes made trying to pick out targets an increasing challenge.  My initial objective had been achieved.  Simply to set up in the back garden of our new house, and see what it had to offer.  It hasn't disappointed whatsoever.  Very little local light to worry about, means that there is no more waiting for optimum night vision to return after getting distracted by lights coming on and off.  After what has seemed to be a long time, it has been great to get back out, and use the SBT again.  Visual observing is astronomy in it's purest form, and is never something to take for granted.  I can't wait to do it again.
Thanks for reading.

Tuesday, 30 April 2019

Astrocamp - Spring 2019

Astrocamp - Spring 2019

Things to do at Astrocamp in no particular order...
  1. Meet up with some awesome people and come away with some great new friends.
  2. Learn loads!
  3. Have your brain slightly melted by a talk on dark matter by a theoretical physicist.
  4. See a home made Martian rover casually drive past while you're catching up with everyone.
  5. Observe.
  6. Win.
  7. Go for a cycle ride around the stunning surrounding mountains, get back to camp, discover that you have cycled 44 miles in the process, and then stop wondering why your legs feel like lead for the remainder of camp.
  8. Find the 'quiet corner' and know when to retreat there.

The meeting up bit.

So, back by some sort of demand, here is my blog post and my take on the most recent Astrocamp held this weekend.  As I type, people are packing away and saying their goodbyes.  Some with very long journeys ahead of them.  Astrocamp brings people together truly from all around the country.  As happens in every camp, there are the now life long friends made at previous camps, and then there are the new recruits, cautiously stepping into their first star party, not knowing entirely what to expect.
Organised by the team that brings you the Awesome Astronomy podcast twice a month, Astrocamp is held in the village of Cwmdu, between Crickhowell and Talgarth, nestled between the Black Mountains and the Brecon Beacons.  Cwmdu has everything that is required to hold a small, friendly star party.  A café, a pub, a village hall, a campsite, and most importantly, access to some of the UKs darkest skies.
The view from the top of the campsite at Cwmdu during Astrocamp, Spring 2019.
I have now officially lost count of how many Astrocamps I have been too, but I keep going back.  For me, it's a step away from everything else I do.  There's no one from work and no one from home, but a completely different circle of friends, all with the Astronomy hobby in common. A true Astro Family.  Each camp now feels like a home from home.  This Spring, it was awesome to meet up with some brilliant people again, particularly Mark and Karen who made the mad journey down from Scotland, and come to their first camp in 18 months.  Quite a commitment, given that Storm Hannah was unleashed on the UK, threatening to blow down anything in her path.  At the risk of turning this post into a list of names, I will leave it there, but everyone who I spoke to, and who took the time to say hello, thank you.  Your were awesome!  One other shout out though must go to Nic and Kevin, first time visitors and who were lovely, letting me join their breakfast table in the village café on Saturday morning.  It was an absolute pleasure to meet you both, and I hope to see you again in September!

The learning bit.

Astronomy is for me, as it is for many others I expect, a lifelong quest to learn.  Even the professionals are in it for the learning.  A hobby where you suddenly know everything would soon become a chore.  Although it could be said that sitting under the marquee on the common, under the red rope lights on Sunday night was one of the more memorable learning experiences of camp whilst talking about docking and waffles, it was indeed at the Spiral Arms that I actually learnt most things.  The main quiz held in the village hall on Saturday is a chance to pick up all sorts of random knowledge.  Learning outcomes can come in many forms.  Some of these nuggets can be hugely complex, others, mere facts that you hadn't appreciated and always incorrectly assumed in times gone by.  Who knew that the Double Cluster is actually in Perseus for example, and not in Cassiopeia after all?
The afternoon at the Spiral Arms is always the highlight of camp for me.  I love the way everyone at camp gets together for the quizzes and talk.  A chance to dust off the brain cells, and fill the grey matter with a bit more knowledge from others.
The gathering at 'The Spiral Arms', the pop up pub at the village hall in Cwmdu.  I'm not sure what Rae has just said to Chris, but those are some evil looking eyes there!!!

The brain melt bit.

The talk at The Spiral Arms this year was given by David Abergel, called 'Uncovering the secrets of dark matter'.  David's background is as a theoretical physicist, and it's fair to say his talk was pretty intense.  After all, it's hard going presenting to a large group of mostly amateur astronomers on a subject which science itself often replies to questions by saying 'we just don't know, but we're looking'.  I found David's talk really interesting, bemusing, complex and amusing, all in one go.  I just keep thinking to myself WIMPS!  I am in awe on how someone can stand up and seemingly deliver something this complex to a listening group completely unscripted and yet still make you feel that you have picked something up and come away from the talk having learned something new.  It's fair to say though, that for a dyslexic amateur astronomer who only just scraped maths in school, and has a memory like a sieve, that I would need to sit a listen to the same talk a few times for some of those things to really sink in.
David, thankyou for coming to camp and delivering your talk.  Hat's off to you, Sir!
David Abergel, this camps guest speaker at The Spiral Arms.

The Martian rover bit.

One of the sights that caused the biggest reaction this camp, was the appearance of a Martian rover.  There I was, standing, talking to my Astro Family on Saturday, when I heard the high pitched whine of servos moving a creation across the Astrocamp landscape.  Piloted by Chris, his latest DIY creation come into view.  Chris has spent many months of time and effort into creating a home made, remote controlled Mars Rover.  Much of the structure is made up of 3D printed components, and aluminium frame.  Based on NASAs Curiosity Rover, Chris's build steps are written up in his own blog.  You can follow his build steps here.  It certainly is a fantastic piece of home build engineering, especially when you consider what the original Mars rover was built to do.  It's fair to say Chris's build wouldn't look out of place on the Martian surface.  However, it did make me think of Marvin the paranoid android from Douglas Adams' Hitchhikers Guide To The Galaxy, with his brain the size of a planet, as Chris's build, with all it's potential for exploration and discovery, was soon turned into Astrocamps very own Deliveroo-ver cake delivery system, as it was loaded up with various pieces of cake, and sent on it's way around camp.
The rover in all it's glory.

The rover and the pilot and creator.

The observing bit.

Astrocamp has an unofficial clear skies guarantee with many different interpretations of it's terms and conditions, meaning that at some point over camp, day or night, and not necessarily restricted to the skies visible from Cwmdu, a clear sky will present itself to someone somewhere, for an undetermined period of time.  This year, we were fortunate to get some excellent observing conditions on Saturday night, the first night of camp.
As a trial, this year, I decided to get a pitch down the very bottom of the site.  These pitches are large pitches, with EHUs available.  What has historically put people off from using these pitches before had been the proximity of the road running along the bottom of the campsite.  Last camp, I went down the bottom of the site one night, to gauge for myself how good, or bad, the observing conditions actually are.  I thought it was worth a try, staying down the bottom of the site.  It's also worth remembering that the good people from Awesome Astronomy also have an agreement with the local authority, that the LED street lamps at the bottom of the site are switched off at 10pm each evening for the duration of the camp.  This makes a big difference.
So, with the first clear night available, I decided to set up my 12" dob on my pitch and waited for it to get dark.  Once the stars started putting in an appearance, I was joined by fellow Astrocamper, Steve, for some views through the eyepiece.  It's fair to say that there is still a bit of local light pollution coming from a single street lamp down the road, over a road junction, but this was only noticeable when moving away from the tents.  With careful siting of the telescope, you can make sure there are tents between your scope and the light, so it becomes hardly noticeable.  
As the constellations were revealed by the darkening sky, Steve and I were able to start picking off various targets.  We had good views of M51 where we could make out the cores of the interacting galaxies with relative ease, even against the distant light pollution caused by the night lights of Abergavenny.  
We then moved the scope higher in the sky, and took in the Leo triplet of galaxies, each being picked out from the darkening background of the sky as light grey wisps.  The 32mm Panaview eyepiece really helped out significantly, allowing us to position all 3 of the galaxy group into a single field of view.
Next we moved away from the SE horizon and pushed the dob around to the constellation of Auriga.  It was time to start picking out some of the riches of it's clusters.  We soon picked out M36 and M37, being able to distinguish a blue hue to the colour of the stars, especially in M37.  The same 32mm eyepiece combined with the dob allowed us to resolve many of the stars as single pricks of light.
Though the sky was predominantly clear, we were interrupted from time to time with passing cloud which gave opportunity to sit down and establish what was to be next on the list of observations to make.
My next target was M3, a globular cluster in the constellation of Canes Venatici.  This took some finding for some reason, although it is reasonably easy to establish where you ought to be looking in the night sky, it did take several minutes to pick out.  However, when I did get it in the eyepiece, the dense core of the cluster stuck out really well.  I was able to resolve the individual stars around the perimeter of the cluster, but, not so much towards the centre.
It's been well over a year since I last did any sort of visual astronomy, and it was simply awesome to be standing at the eyepiece once again, instead of running my astrophotography set up.  Like many observers, I carry a notebook with my kit, and take notes on what I have seen each evening.  In the back of the notebook, I have a tick list of the remaining objects to see in various catalogues.  On Saturday, I turned to my Messier tick list, showing the remaining objects I hadn't yet managed to observe.  Working through that list, I managed to tick off two more.
The first new tick was M61.  This is a barred galaxy in the constellation of Virgo.  Virgo is in prime position this time of year, ready to display is vast collection of galaxies to observers and imagers alike.  At magnitude 10.1, it is beyond the capability of smaller aperture scopes.  I wouldn't be able to pick it out with my 150mm reflector or 80mm refractor.  The 300mm dob has the light gathering ability to help me pick it out though.  Even then, it is a tricky object to locate amongst many other galaxies in the locality, but I was confident that I got it and as pleased to be able to strike another one off the list.
My final observation for the evening was something that I have wanted to observe and image for a long time.  M104 is the Sombrero galaxy.  To be honest, this one wasn't in ideal position, being quite low toward the horizon in the direction of Abergavenny, but once I did locate it, I was pleased to be able to see the characteristic black line that appears to strike through the lower portion of the galaxy.  This is definitely a target for the AP list, although just to be able to observe it is quite special in itself.

The win bit.

As mentioned earlier, the highlight of camp for many people, especially if there is not much observing to be done, is the afternoon in the village hall.  In all the camps I have been to, I have never been part of any team that has won anything, but have always come away having had a brilliant afternoon.  This losing streak came to an end in spectacular fashion this Spring.
The quizzes are very light hearted, and teams can be as big or small as you want.  I joined a team made up of very familiar faces, and we sat down to quiz away.
This year, the top 3 teams all finished with 23 points, and after a tie break, we came in 3rd, receiving a pair of Celestron binoculars for the team.  Obviously, it's a little impractical to share these out, so it was decided that Chris should have them to be used in his outreach work within his local astronomy society.  A well worth cause for sure.  But the winning didn't stop there!
The notorious Masters of the Universe quiz is the last thing to be held in the afternoon.  This is fiendishly difficult requiring a great deal of knowledge.  So tough are the questions (of which there were 8), no one has ever come anywhere near scoring full marks.  This year was no different.  Our teams winning score was a fantastic total of 3!  Alas, I could not contribute to any  of the questions at all.  They were well beyond me, but by virtue of just sitting on the same table as the clever people, seemed to get tarred with the winners title!  The prize, perhaps more important than any other - beer!

The cycle ride bit.

The Astrocamp programme is crammed full of things to do.  From organised solar observing to tutorials, to quizzing and to the high tea gathering on the common on Mondays.  However, there are gaps in the programme that allow some down time.  It allows people to go off and explore the surrounding areas either on foot, or by vehicle.  Of course, many also chose to take the chance to get some extra sleep in the peace and quiet of the morning.  This year, I took my bike to camp with me.  No matter where I am, or what time I go to bed, I tend to wake at the same time, around 6.00am.  When I woke on Sunday morning, the campsite was silent.  I got myself ready, and tip toed out of camp at around 6.45 and set off.  Around 5 hours later, returned to camp in time for lunch, having covered 44 miles of a circular route taking in some of the best scenery that the Black Mountains has to offer.  My route took me to Talgarth, then onto some old stomping grounds of Three Cocks and Tregoyd, (where I worked some 20 years ago), onto Hay on Wye and then Capel y Ffin, taking in Gospel Pass on the way.  Eventually, making my way back to Cwmdu via Llanbedr and Crickhowell.  It's fair to say that the ride was a bit ambitious for me, especially when I realised at one point that if I didn't stop and turn soon, I was heading to Abergavenny, in completely the opposite direction from where I needed to be!  Am I glad I did it though?  You bet I am!
In completely the wrong order of appearance, pictures of my ride around the foot, and then over the top of the Black Mountains.

The quiet corner bit.

And so another awesome camp comes to an end.  This camp seemed to go so quickly, but I look back at everything that I did and reckon that I couldn't have fitted any more in if I had tried.  From sleeping in the van the night before camp started, waiting for Storm Hannah to do her worst, to getting the feeling of the Sun's influence on my face on Monday morning, I packed up the van and headed home happy.
My neighbours for this camp were Steve and Jax, along with their dogs.  A massive thankyou to them both for being great Astrocamp neighbours.  A very special hat-tip to Jax for an amazing home cooked lasagne too!  How can you repay someone for feeding you something like that when you have nothing prepared in return?  I am extremely grateful.  Thank you.
My decision to get a pitch right at the bottom of the site raised some questions by some.  Why would you go down there?  The road, the lights, etc.  Often seen as a last resort by some in the search of the last of the pitches available with an EHU, I believe those pitches offer a lot.  In particular, a quiet corner, away from everything else.  Granted, being near the road, during the day time can mean that you are slightly closer to traffic noise than the rest of the camp.  But honestly, you don't notice it a huge amount.  Actually, I really did like this quiet corner of camp.
It's fair to say that this is a very social event, and rightly so.  It really wouldn't be the same without people coming together in the way they do.  For many of us, it is the only time in a year that we are able to meet up.  It's also fair to say that things can get quite raucous and noisy when the drink has been flowing, regardless of the time of day or night.  There are some who love that aspect, and it's good to be able to see people let their hair down and enjoy their camp.  There is also a conflict.  With people who want the partying and the late nights when there's no astronomy to be done, there are also those who want or need the peace and quiet.  Particularly those with younger guests.  It is a family event after all.  The opportunity to get rest at night, and relax is important, and makes the event special for those too.  What no one would like to see is for people get put off from attending what is a truly unique experience.  Will that happen in the future?  Who knows.  
As ever, my expressed thanks must go to the organisers, Ralph, Paul, Damien, John and of course, the one that keeps them all in order, Jen.  It's been another memorable camp, and I hope to see you all again in September.  Thank you so much.  It's truly appreciated.
Finally, thanks to you for reading.  My blog posts on my experiences at camp, are exactly that.  I'd love to hear about other peoples experiences too.  The best bits, the tough bits, the whole thing.  Until we meet up to do it all again in September, best wishes and clear skies.
The quiet corner, bathed in sunlight.

Saturday, 16 February 2019

What Controls The Hardware - Update

A couple of years ago, I put up a blog post about all the software that I was using at that point, to control the hardware I had at the time.  Well, I thought it was time for an update.  I've changed my mount, my camera and have picked up several other hints and tips since then, and my software has changed to keep up.
One other thing that I have recently added to my collection of hardware is a dedicated imaging PC.  The Intel NUC 7i5BNH is around 15cm square and around 4 cm tall.  This week, I spent 2 evenings putting on the operating system and all the software I need to start using it.

The PC

The new NUC carries a 7th generation Intel i5 processor which is more than enough to support the software I require.  I won't be using this for image processing, so anything more than this would probably be a bit of a waste.  The beauty of the NUC is that once you have decided what processor you want, you are then free to chose the RAM and hard drive size, and fit them accordingly.  So, I went with 8GB RAM and a 250GB SATA Solid State Drive.  The NUC also comes with an on-board wireless access card.
I've installed:
  • 64 bit Windows 10 Enterprise.
  • Bitdefender antivirus.  
  • The driver bundle was downloaded from the Intel website, and all relevant drivers were installed.  Windows 10 actually does a reasonable job of installing what it needs, but given this was a vanilla build, I wanted to use all the manufacturers drivers from the start.
  • I gave the wireless access controller a fixed IP address, and enabled RDP which allows me to remote onto the NUC from another machine on my home network.

The Astro Hardware

Everything else is fairly standard astronomy kit.
  • SkyWatcher EQ6-R Pro mount.
  • Altair Hypercam 183c (v1) for imaging.
  • GPCAM Mono for guiding.
  • USB3 12v hub

Installing The Software

There's a requirement to install the software and drivers for all the kit in specific order.  None of the installs are particularly tricky though.  Where I can, I've put a link to the download locations I used.

Cartes du Ciel v4.0

I use this for selecting targets and slewing the telescope to them.  It saves having to rely on using the handset on the mount.  It's free and opensource software. available from here.  Once installed, there is not much to do, other than set up your location.  If you move around several observing locations, you can save all the locations in the 'Observatory Database'.  All you need is the GPS coordinates of the location.
At the end of the process, the software will be able to connect to the mount, but there are a few more things to go through first.

AltairCapture 3.7

This is imaging/capture software from Altair, designed to work with their cameras.  Although I don't actually use this software, there is some important information on the Altair downloads website regarding the drivers of the Altair cameras.  From experience, I can say that as long as their instructions are followed IN ORDER, then you shouldn't have any problems.  You don't necessarily need to configure Altair Capture, but by installing their software, all the latest drivers for all their cameras are installed.  Note, DO NOT plug any camera into the PC before installation of the software.

SharpCap Pro 3.2

I have invested in a lifetime license for SharpCap Pro, and use it as my only image capturing software.  If I buy a different camera in the future, then it supports cameras from all the main manufacturers, and is continually being developed and added to.
According to the SharpCap website download page, most users should only ever need the 32 bit version of the software.  So, that is what I have used.  I downloaded the latest version, installed it and applied my SharpCap Pro license.
As I had installed Altair Capture before hand, I was able to connect my Hypercam and GPCAM to the NUC via the powered USB3 hub, and connect SharpCap to them both.  I use SharpCap for polar alignment, via the GPCAM guide camera, and then perform the rest of the imaging with the Hypercam, which is why it was important to check I could connect to both cameras at this point.

Altair ASCOM Drivers v 1.4.10

These are the first of 3 sets of ASCOM drivers required for each piece of software to talk to hardware.  In this case, for the Altair cameras.  I downloaded these from a link the on the Altair downloads page.

.Net 3.5 for Windows

Although available for download, it is actually a feature which I enabled within windows.  After enabling this feature, the NUC needed a reboot.  It is a prerequisite for the next download and install.  Without this in place, I could not continue with the remaining installs.  A quick internet search will tell you how to enable the feature.

ASCOM Platform 6.4 SP1

This is a platform of different ASCOM drivers for controlling all sorts of hardware.  The latest platform is available from the main ASCOM downloads page.

SkyWatcher ASCOM Drivers v 6.0.6262

These drivers are the final piece to the jigsaw, allowing the computer, and the various pieces of software to talk to the SkyWatcher mount.  These are also available from the ASCOM website. under their Telescope/Mount Drivers section.

PHD2 v2.6.5

This is guiding software, used for tracking a star in the field of view of the guide scope.  It determines if the star is moving within the field of view, and then sends guiding adjustments to the mount to ensure the guide star stays in the same place.  The latest version is available from the PHD Website
Once installed, PHD2 will automatically enter a small wizard to set up some guiding parameters.  Some of these it sets up itself, but I needed to add the focal length of my guide scope, which is 206.6mm

That was it for the basic installs.  The NUC was now able to talk to the hardware, and all the software was able to communicate with what it needed to.  Each piece of the software needed a little more configuration in it's own right, but no further set-up was required.
I expect I will need to refer back to this in the future when the time comes to rebuild, the NUC, or if I invest in a new machine.  Up until that point though, I hope it helps others too.
Thanks for reading!

Monday, 11 February 2019

Pixinsight Progress, The Flaming Star and Orion

The Flaming Star Nebula - IC 405

I've had somewhat of a hiatus from astronomy and astrophotography for a while.  So, when a weekend at the start of February presented itself with good weather (a rarity in these parts this Winter) and a new moon, I was determined to get outside with all the kit.  Setting up out the back garden highlighted how rusty I was, when it come to getting everything right.  The slick operation that had been refined over the many months previous had turned into one of head scratching and re-tracing steps to get things all done and dusted.  Eventually, I had everything ready (ish) and so I threw myself into my first night of imaging for quite a while.
I wanted to try for a new target, something that I had not imaged before.  Not knowing if it was even possible to pick up this nebula, I selected IC 405, The Flaming Star Nebula.  I had seen many images of this by people using mono CCD cameras, but nothing from the Hypercam range of OSC cameras.  I decided to give it a crack, and collected 30 light frames, followed by 29 dark frames.  The next morning, I collected 30 flat frames.
IC 405 is in the constellation of Auriga, and is around 1500 light year away.  This image is made up of 30 x 3 minute exposures, 90 minutes overall.
As a first attempt at the target, and the first time back in the astronomy seat for a while, I'm quite pleased with it.  It's a bit noisy, which is something I could sort out with better processing, and different camera settings, but overall, I'm happy.

The Orion Nebula - M45

That night, I decided to image a second target.  M45 is the 'go to' target for many imagers at this time of year.  After all, it's well positioned, bright, and colourful in OSC and DSLR cameras.  Surprisingly though, this is only the second time I had imaged this target with the Altair 183c Hypercam.
Because of it's brightness, I needed to be careful not to blow out the core of the image too much.  In a way, restricting the amount of data I was collecting.  It's very hard to do this, and the final image relies on some processing to bring out the detail in the central, brighter core of the nebula.
I was able to use the same dark and flat frames when creating this image, but this time, I only used 22 light frames.
The Orion Nebula is in the constellation of Orion.  On a clear evening with good quality skies, it is visible naked eye and is a mark of how much, or how little light pollution you have.  This image is made up of just over an hour of exposure time.

PixInsight and Progress with Calibrating

So to the crux of this post.  It was great to get out under the stars again.  To have everything set up, working away without too much hassle was a timely reminder to me of how much I had missed sitting outside in sub zero temperatures, getting annoyed with neighbours lights, and not being able to feel my fingers.  Good times!  But, the big development I made this time around, and the thing that I had learnt came at the calibration stage of processing.  Last September, I thought I made a huge break through in the calibration stages of my images.  In truth, I probably did, but could I repeat it?  No.  I refer to the thing that is common with the highly sensitive Hypercam 183c series, and that is the amp glow and sensor/star burst that appears in the right side frames.  Particularly in the dark and light frames.
A single dark frame, stretched in PixInsight shows up the anomaly.

Here's the theory if you're not familiar with the process.  The light frames capture all the detail from the target you are imaging.  But, they also contain lots of other anomalies.  These could be sensor anomalies as is the case with the Altair Hypercam, but also pixel noise etc.  Taking dark frames (exposures with the cap on) gives you a series of frames that contain nothing other than whatever is produced purely by the camera and the imaging train.  During the calibration process, in principle, you stack up all your dark frames to produce one single 'master dark' frame.  All the noise and anomalies in this master dark is then compared to each of the light frames.  The software (in this case PixInsight for me) looks at the master dark frame and subtracts whatever the anomalies are in there from your light frames.  Theoretically, you are then left with a much cleaner set of light frames which can then be further calibrated before finally being stacked to produce your single image, ready for processing.  Hope that makes sense.
In my case though, I couldn't get this to work reliably.  I would go through the whole calibration process, and still be left with a final image containing all the noise and anomalies which should of been removed.  Then, along come the eureka moment.
Over the last 18 months, I have been following the 'Astro Dude' YouTube channel, run by Mitch.  He has produced an excellent series of 12 tutorials for calibrating and processing data in PixInsight.  I was having a browse through the channel, and noticed a video that he produced around 6 months ago.  It was this video that held the hidden gem.  The awesome thing is that Mitch is also a Sharpcap Pro user, a Altair Hypercam user and a PixInsight user.  Rather conveniently, the exact set of tools that I use!  I set about watching the video, then watching it again making some notes.  And then finally again to make sure that there was nothing that I had missed.  I followed my notes, using the exact same settings as Mitch did in his video, and like magic, no sensor noise or no amp glow in my final image stack!  I was made up!  If you want to see this video, well, here it is...

I don't know about you, but seeing things in video, as someone else is doing them is all well and good.  But when it comes to doing it myself, I find it easier to have everything in notes with some screenshots etc.  So, I set about typing up my notes which I can now carry with me, and refer to whenever I need to.  I've made those notes available for download if you want them.  A huge thank you to Mitch for putting up this tutorial, and a massive plug for his YouTube Channel  Definitely subscribe to it, if only to pick out little gems in some of the videos.
So, that about wraps up this post.  Thanks for reading!

Sunday, 4 November 2018

2 Clear Nights - Part 2

The Pacman Nebula - NGC 281

This isn't some random throwback to a popular 1980's videogame.  For the benefit of the uninformed, there really is such a thing!  The Pacman Nebula is given it's nickname because of the shapes similarity to the videogame character.  It's high up in the sky at the moment, in the constellation of Cassiopeia, and though visible all year for us in the UK, it really is in a great position during the Autumn evenings.  Visually, NGC 281 is a tricky target to observe without plenty of aperture, though it is magnitude 7.0 or thereabouts.  It's much further away than Andromeda, at around 9500 light years away, but as is often the case with nebulae, the more time you can spend collecting data, the more extent of the nebulae you will eventually be able to reveal.
Taking on this target was a bit of an unknown for me, but what I was willing to do was put in the hours to get the data.  Because of it's current position, there are quite a few images of the target appearing on various groups and forums around the internet, so it was easy to get an idea of what I should be able to get on a successful evening.

Collecting the data

In one of my astrophotography books, the description of how best to image the target assumes the use of a mono CCD camera and a combination of filters.  Well, I don't have any of that.  The 183c Hypercam is a One Shot Colour (OSC) CMOS camera.  Fortunately, the book also suggested that capturing the data should also be possible using such a camera.
So, I set about getting everything set up.  In the forefront of my mind when I come to compiling the imaging run was the accidental mistake I made earlier in the week where I inadvertently left a smaller ROI on the Sharpcap settings which meant that I wasn't using the full size of the sensor chip.  This time, I made sure I put that right.  As I mentioned in part one of this double posting, I always like to try something new each time I go out.  This time round, I wanted to attempt my longest imaging run to date.  I read many forums and posts of people quoting that they have collected 10, 15 even 20 hours of data on a particular target.  I'm not in the position to do that.  I haven't learnt how to break my imaging runs up over several nights and still get everything to stack properly.  That's another lesson for another night.  But, I could collect 3 hours on a single run, plus calibration frames.  There are plenty of things that need to happen simultaneously in order to have a successful imaging run, so the target for this particular night was to get a good clear run for 3 hours.  You could be mistaken for thinking that once the whole process is started, you can just sit back and let everything happen.  In truth, it's not far off, but you always need to keep an eye on the computer, the focus, the progress of the data capture, the dew, the power supply for the mount, the guiding and local nocturnal wildlife even!  That's amongst a few other things.
So, setting up the imaging run for 60 x 3 minute exposures and making sure that I had enough time to run off sufficient dark calibration frames after all the subframes were collected, I settled back and watched the data roll in.

The final image

And here's the final image.  I had two attempts at stacking.  Once with the PixInsight software, and once with the DeepSkyStacker software.  The latter produced the better stacked result, so that was the image I took forward to the rest of the processing steps in PixInsight.  Notice the number of background stars in the image due to it's apparent position in the arms of the milky way!

NGC 281 - The Pacman Nebula.  See the bright star in the centre of the image which represents the eye of Pacman!
I now wait for the next opportunity under a clear sky to get back out there and see what I can conjure up next.  There's so much to learn!  Until then, cheers :-)

2 Clear Nights - Part 1

Andromeda - M32

The end of British Summer Time is really when Astro activities begin to ramp up for the winter.  The opportunity to be observing or imaging within an hour or so of getting home after work makes the whole thing much more accessible.  It's now possible to get a good 4 or 5 hours of time at the scope and still get to bed at a realistic time on a school night.  But still, the opportunities need to be embraced when they present themselves.
So, this passed week produced 2 clear nights with steady a steady sky, and the moon not putting in an appearance until the early hours.  As I gain more experience at this imaging game, I'm learning to push my equipment further than I have before.  Every session present a new lesson, and the first session of the week was no different.

Andromeda - The Accidental Core

M32, the Andromeda Galaxy, is well positioned in the Autumn sky, high up above the surrounding rooftops.  A very popular target, because it's big, and bright.  Sometimes it's brightness can present it's own issues which I shall come to soon.  I've imaged the galaxy several times over the last few years, but as my knowledge of processing in PixInsight and use of Sharpcap 3.2 increases, it's always a good target to revisit.  I can compare my images to previous ones and it helps remind me about how my imaging is improving.
With the usual setup and alignment tasks carried out, I slewed the scope around to Andromeda and started the process of compiling the imaging run.  All my imaging at the moment is carried out using Sharpcap 3.2.  It's got lots of great features, but you don't have to know about all of them to get imaging.  I've started with the basics of camera control (exposure length and gain), but make a point of learning a little bit more about it each time.
Framing of your target is really important.  Just as important as focus.  In my passed images from a few years ago, framing was always a bit hit and miss.  This time, I used Sharpcap to help get the core of the galaxy in the centre of the frame.  To do this, I used the auto stretch function on the display image.  It takes a single frame, stretches it to bring out the brighter parts of the target and allows you to then used the mount controls to gently nudge the centre of the target into frame.  Used in conjunction with the crosshair reticule on the image screen, framing a target image becomes really easy.  Quite simply, I can't believe that I hadn't come across this before!
So, everything framed, focussed and gain and exposure settings set up, guiding enabled and running, I started the image run.  I was aiming for 40 x 2 minutes exposures for the evening.  That left me with plenty of time to run off some dark calibration frames before packing it all in.
Around half way through the run, I noticed something on the Sharpcap software that I had not noticed before.  I didn't want to stop the run and potentially waste the data I had collected so far, so I let the run complete.
The previous session in which I imaged the Witches Broom Nebula, I started playing with binning.  I run that session binning the data 2x2.  It was successfully, and produced a pleasing image.  However, what I didn't realise, was that when those image run settings were saved, removing the binning settings later returned to the normal 1x1 binning settings, but it also produced a smaller ROI scale, or, Region Of Interest.  In effect, it allows you to use a smaller proportion of the cameras chip resulting in a smaller sized image for processing later.  It's also very useful for imaging smaller targets like planets or small nebula.
After the image run on Andromeda was completed, I stretched one of the sub frames and immediately saw what had happened.  Andromeda is a huge target.  It fills the full frame, and a bit more of the Hypercam when used with the 80 ED-R.  So, the effect of having a smaller ROI set up in Sharpcap meant that instead of capturing the true expanse of the galaxy, I actually collected a load of data, more on less just of the core of the galaxy.  Now, as I mentioned earlier, the galaxy is really bright.  More often than not, the core is so bright that it appears blown out in all but the best of processed of images.  Initially, I was disappointed.  My final unprocessed, but stacked image just showed a large yellow-white blob taking up the majority of the frame.  Not wanting to waste the data totally, I went ahead with the processing anyway.  And this was the surprising result...

M32 - The Andromeda Galaxy (core).
It was a big, but pleasant surprise when I managed to reveal this much detail in the core of the galaxy.  To give a comparison, this is what the stacked, but unprocessed image looks like.  Remember that this is what I get as a result of stacking all my light frames and then performing an initial stretch of the data.  It also gives a good idea of what further processing steps achieve.

M32 - Stacked and Unprocessed.
In particular, the core is no longer a white blob, and individual stars and dust lanes can be resolved.  The next time I image Andromeda, I'll be using the same settings, but ensure I'm shooting full frame images.  I'll be chuffed to bits if I get this level of detail across the whole image.  Definitely one for the to do list!
That's Part 1 of this post done.  In the next part, I'll be looking at the results of the second clear night from last week.  Until then, cheers!

Saturday, 15 September 2018

M57 - The Ring Nebula and Dealing With Hypercam Noise

M57 - The Ring Nebula, and the story behind the image.

Every image has a story.  Be it about the subject itself, the location or how the image was obtained.  This image represents for me 2 things.  Firstly, proof that not all astrophotography images are about full frame objects, or targets cropped within nanometres of their boarders.  An impressive planetary nebula nestled in amongst a field of view littered with stars, M57 is amongst the smallest targets out there to image, so getting any detail in it at all can take some effort.  Secondly though, the image has taught me a lesson.  One that I hope will now significantly improve all my future images taken with the Hypercam 183c.  More on that in a moment.
My last post set out the process I go through to collect the data for my images.  Whilst getting the screen shots for that post, I imaged M57 - The Ring Nebula.  I have now had the time to go through the steps of stacking and processing the data to produce the final image.  You see many images of this target because of it's apparent brightness, but more often than not, the images will be cropped or enlarged to see the Nebula in as much detail as possible.  Indeed, I have done this before myself.  This time however, I wanted to add a sense of scale to the image, so only cropped the image where absolutely necessary to remove the rough edges of the final image after the stacking process.

Almost lost in a myriad of stars, M57 is a popular visual target.
The details behind the image:-
  • 25 x 180sec light frames
  • 25 x 180sec dark frames
  • 31 x 90ms flat frames
  • Stacked and processed in PixInsight and GIMP
So, what of the one big learning aspect of this image in particular?  Well, I have already divulged that secret!  Ever since I started using the Hypercam, I have struggled with the anomaly of noise from the sensor encroaching the righe side of every image.  To be clear, this in itself is perfectly normal.  It is behaviour (though undesirable) of the Sony sensor used in the cameras, and it is found in every camera using that particular sensor chip.  Time after time, I have been told that correct use of calibration files (darks and flats) will get rid of the noise in the final stacked image.  To illustrate this noise, as well as the amp glow from the chip, here is a single 3 minutes sub frame, stretched, but not debayered.  Notice the amp glow across the top and bottom edges, but in particular the additional noise on the right edge which looks like some sort of extravagant starburst effect from a bright star just out of frame.

As more and more of these images are stacked up, the noise become more and more prevalent, and up until now, I have struggled to get rid of it during the stacking and calibration process.  This has meant that many of my images have been significantly cropped to cut out the noise.
I think I managed an imaging run once earlier this year where I successfully produce a stacked image without the noise on it, but I have failed to remember how I did it.
After much more thought and reading, I understood that the dark frames should be removing this sort of anomaly, so I started wondering if I just wasn't producing enough information in the master dark file to take care of this noise.  So, that left me with one option.  To increase the number of dark frames I was taking.  I have never found a definitive ratio for the number of light frames to dark frames to flat frames to obtain for each image.  Sometimes it has been 60 light frames and 20 darks.  Other times 20 light frames and 10 darks.  For this image in particular, I went with the approach that if I took one dark frame for every light frame, then I would be able to experiment by changing the ratio each time.  This is when I seemed to have struck gold.  
This is what the final stacked image looked like when PixInsight had finished the stacking process.  Remember that the image has had not been cropped at this point, has had no processing done to it, but has been stretched to show the detail available.

Notice that the noise and a majority of the amp glow has now been dealt with successfully, allowing me to make far better use of the whole frame, instead of cropping out any interference, and loosing about 1/3 of the image in the process.

So there you go, one image and 2 stories.  Now it's just a question of making sure that this is repeatable.  It all come down to the fact in this instance that I simply didn't have enough dark calibration frames.  All I need to do is get out there on the next clear night and repeat.
I hope this helps other owners of the Altair Hypercam 183c series of cameras.  I see it raised regularly in various forums and groups, but no-one as far as I can see has been able to say definitively what they do to combat the problems.
Thanks for reading, and clear skies! 

Thursday, 13 September 2018

Data Capture Workflow - Astrophotography and the Hypercam 183c

Altair Hypercam 183c Workflow

Hello!  After discussing with various people, the topic of how I go about preparing for and collecting my data for my images, I thought it would be useful to put together a workflow for others to consider using as a basis for their own imaging process.  I haven't gone into too much detail with settings in each of the steps.  These settings will be different for each person and each combination of kit, but it will be a good starting point.  So, before I proceed, this is a list of what I use for my own imaging.
  • SkyWatcher EQ6-R Pro mount.
  • Starwave 80 ED-R telescope.
  • Starwave 50mm guidescope.
  • GPCAM Mono guide camera.
  • Altair Hypercam 183c colour CMOS imaging camera.
  • Altair CCD light pollution filter.
  • LED artists tracing light board.
In terms of software, this is what I use.
  • Sharpcap Pro 3.1
  • Fits Liberator
  • Cartes du Ciel
  • PHD2

Polar Alignment

Every article I read about imaging and using an EQ mount always talks about polar alignment.  As I have found out, there are numerous ways of achieving polar alignment by using all sorts of different gadgets or software to aid the process.  The EQ6-R Pro comes with it's own polar scope, but as yet, I haven't used it.  Instead, I start off by ensuring my guide scope and main scope are aligned fairly well to true north, and the latitude is set correctly for my location (approximately 51.9 degrees north).  It doesn't have to be exact, but personally, I like to get things as accurate as I can.
My personal preference for achieving a good polar alignment is to use Sharpcap.  In Sharpcap Pro, there is an in built polar alignment tool which connects to your guide camera.  You need to have your mount aligned roughly to start off with, give or take 5 degrees or so.  Sharpcap can then plate solve the stars it sees through the guide camera and guide scope, before then giving you directions for adjusting your mount.  I took this screenshot showing what I saw during the process.

Polar alignment routine in Sharpcap Pro

3 Star Alignment

Once the mount is polar aligned, I go through the process of performing a 3 star alignment of the mount.  This process allows the mount to learn where given star are in the night sky, and can be incredibly accurate.  To carry out this alignment, I use an illuminated reticule in the telescope's eyepiece holder.  This reticule given me a crosshair target in the eyepiece meaning I can be sure that the stars used during the 3 Star Alignment routing are perfectly in the centre of the field of view.  
The alignment is carried out following prompts and instructions on the handset of the mount.  Once alignment is complete, the scope itself is ready to use, and it's time to move onto preparing the specific imaging hardware.

Fit and Focus the Hypercam

Once the scope is aligned, I remove the diagonal and reticule eyepiece, fit the 80mm extender, filter and camera and once again, return to Sharpcap.  The next part of my workflow is to get the Hypercam focussed as best I can.  I don't have a motorised auto focuser, so this is an important step that I need to get right first time.  If I need to make significant changes to the focus during the imaging run, I run the risk of making too much of a change and possibly stopping the latter process of stacking and image integration from running smoothly.
To achieve focus, in Sharpcap, I point the scope at a bright star, and then fit a bhatinov mask.  I used the zoom feature in Sharpcap and then turn the focus knob accordingly.  The idea is that the diffraction spikes caused by the mask are equally spaced when good focus is achieved.  The screenshot below shows the exposure time and gain used during the process of focusing, and the equally space diffraction spikes.

Equally spaced diffraction spikes showing good focus.

Choosing a Target

I am now ready to slew the telescope to a chosen target.  To do this, I used planetarium software called Cartes du Ciel.  I could just use the hand controller connected to the telescope, but for ease of use, I prefer the software.  For this particular night, I decided to image the Ring Nebula, or M57.  Once the mount is connected to the laptop and the software is launched, I can select a target and allow the mount to slew the telescope to the target.
M57 selected in Cartes du Ciel.

Framing the Target

Even the most accurate of go to mounts will still require the finest of adjustments if you plan on imaging a target.  This is especially important when imaging either very small, or very large targets.  You want to be sure that you fit as much of the target in the frame, and get it as central as possible.  To do this, I switch back to Sharpcap and adjust the exposure and gain settings to give me some sort of idea of where the target is.  M57 is actually quite bright, so it's fairly straight forward.  However, for dimmer targets, it can take a bit of time to get things framed accurately.  Sharpcap has a crosshair tool to help framing objects accurately.
In this screen shot, you can make out the shape of M57 near the centre of the crosshairs.  You can also see the scope controls available within Sharpcap which allow you to make fine adjustments to frame the target exactly how you want it.

Moving M57 into the centre of the frame using the crosshairs and mount controls in Sharpcap.

PHD2 - Guiding Calibration

So far, all the work has been done to get the mount slewing to targets as accurately as possible, and the target selected, framed and put into focus.  However, for prolonged exposures of more than around 60 seconds, it is necessary to run guiding software to improve the accuracy of the mount. In essence, guiding locks onto a star via the guide camera, tracks it as it moves through the sky and then issues adjustment commands to the mount to keep the guide star in the same location relative to the field of view.  
In PHD2, the guide camera is connected to the software, and as best practice, I use the Guiding Calibration feature in the software to 'teach' it how the mount is currently reacting to commands.  A guide star is selected and then commands are issued to move the star North, South, East and West during which time, PHD2 takes measurements of how much the mount has to move to move the star the required amount of steps.  The process is fully automated once started.  Once complete, guiding starts automatically.  If you want, you can leave it guiding from there.  However, I chose to perform some additional steps.
This screen shot shows the calibration steps being carried out.

PHD2 Calibration steps.

PHD2 - Guiding Assist

There are many settings in PHD2 which can be changed to try and improve performance.  To be perfectly honest, I don't understand most of them, but they all seem to be important.  So, to help me put the correct values in all these places, I use the Guiding Assist tool in PHD2.  Guiding Assist stops any guiding that is taking place and just measures the movement of the selected star.  From these measurements, the software can measure the increments in which guide commands need to be issued, and also if selected, the backlash of the mount.
Guiding Assist is left to run for around 2 minutes so it can make all the measurements it needs to.  Once completed, it then allows you to adopt the suggested settings and automatically enters them into the appropriate fields.
This screenshot shows the measurements that are taken and the different information it provides, and the second screenshot shows the results at the end of the process.  Remember that this changes from night to night and needs to be done every time everything is set up.

PHD2 Guiding Assist in progress.
PHD2 Guiding Assist results.
Once the settings have been adopted, PHD2 then starts guiding.  Before I carry on, I prefer to leave the guiding process run for a few minutes and watch the graph in the software,  Theoretically, the flatter the lines in the graph, the better guiding is working, and the better the mount is set up.

The difference in the graph shows the point when PHD2 Guide Assist stops taking measurements, and then starts guiding.

Starting the Imaging Run

At last, I'm ready to start turning my attention to capturing my images.  There are a final few calibration steps I carry out before starting the image capturing.  Back in the Sharpcap software, I have recently started making use of the Smart Histogram.  The feature analyses the sky conditions, and with some input from me about such things as how long I want the total exposure to come to, and the shortest and longest individual exposures I am willing to use.  For example, if I know I only have 3 hours total to spend, I can tell Smart Histogram that I want to collect 90 minutes worth of data in total.  Smart Histogram is then able to give me the optimum gain and exposure length to use for the parameters I set.  Again, this process can take a bit of time because Sharpcap actually takes a range of individual frames of differing lengths and gains to build up it's graph.  The remaining time left out of the 3 hours I can use to collect calibration frames for use during image processing.
This screenshot shows the histogram analysis in action.  Once the results are displayed, you can input them into Sharpcap ready to start the imaging run.

Smart Histogram calibration steps.

The Capture

Now it's time to start the data capture process.  The mount is set up, the software is configured, guiding is running and I now know the optimum settings to apply to the Hypercam in Sharpcap.  All I need to do is set the imaging run off within Sharcap.  I can set the imaging run to either take a fixed number of exposures, to run for a certain total amount of time, or take pre-configured numbers of exposures.  Using the information from the Smart Histogram tool, I usually know by this point how long or how many frames I need to take.  It's just a question of applying the settings and setting the process off.
Each frame is displayed in Sharpcap so you can see what's going on.  You can also see how much time is left in the run and how many frames have been taken.

Hypercam settings used for imaging M57
It's important to keep an eye on the PHD2 graph throughout the imaging run.  Normally, just keeping an eye on the graph is sufficient.  However, PHD2 does give an audio and visual alarm if it loses contact with the selected guide start because of cloud or dew.  To monitor this, I tend to have both the PHD2 window and the Sharpcap window open at the same time.

Monitoring the data capture of M52, and PHD2's guiding performance.

Capturing Dark Calibration Frames.

Once the main imaging run is complete, and all the light data is collected, my last job of the night is to collect the Dark calibration frames.  These are simply additional images taken using exactly the same parameters as the lights at the same focus and camera orientation.  The only difference is having the cap on the end of the telescope.
This screenshot is of Sharpcap taking the Dark calibration frames.

Collecting Dark Calibration frames.

Flats and Fits Liberator

This is usually the last task of the night.  The following morning, I will then take my flat images, but they can be done at anytime providing the focus and camera orientation are maintained throughout.  This is really important, so usually, I take the scope off the mount at night, put it onto a flat surface and don't touch anything until the flat frames have been acquired.
From reading up on various forums, and asking questions about obtaining flat frames, I have settled on the routine of:
  • Stretching a white T shirt over the end of the telescope.
  • Use an LED tracing/drawing board to give an even light covering over the end of the scope.
When I first got my Hypercam 183c, I joined the Altair Astro Google Group.  On there, I made contact with RobinG (who I think is the writer of the Sharpcap software), and he offered the following piece of information on taking flat files with the Hypercam 183c, and how to work out the correct exposure etc.

Mean flat values to aim for in Fits Liberator
Taking this on board, I then set about experimenting taking single flat files and opening them in Fits Liberator until I achieved the desired values.  It's important to note that I leave the gain settings the same, and purely work with exposure length.  It's also important to note that the optical train remains exactly the same.  In other words, if all the images are taken using a certain filter, then that filter remains in place for the flats.
This is a screen shot of Fits Liberator showing where to find the mean values to aim for.

Fits liberator is free software available to download and use.  The image statistics highlighted in yellow is where to look for your flat files values.

So that's my workflow for a typical night's imaging.  It seemed quite daunting at first, but once I got used to it, I found that I can get through everything in about 30 minutes.  Many of these steps will be redundant in a permanent set up in an observatory.  That would be ideal.
Anyway, thanks for reading, and I hope you find it useful.

Tuesday, 11 September 2018

Astrocamp XIII - Cwmdu we had no problem.

Astrocamp XIII - I Was There.
A highlight to the year for many people.  The anticipation.  The constant checking of weather apps.  The buzz.  The laughs.  The astronomy.  The traditional post camp hangover.  This weekend, we returned to the familiar surroundings of Cwmdu campsite, and attended Awesome Astronomy's Astrocamp.  It was said that in all the camps so far, nothing had gone particularly wrong, and that if it ever will, it was bound to happen at Astrocamp 13.  A rather odd expression given that the whole event promotes evidence based science and rational thinking!  Quite amusing.

Arrivals T-1 day...
On the run up to camp, I had put forward the idea of having kind of a popup Astro DIY workshop and encouraged people to come along and show off their DIY modifications and projects.  I mentioned the idea on the camp Facebook page and was really pleased to find it well received.  Throughout the weekend, a variety of people stopped around where we were set up on the campsite and were keen to check out each others ideas.  Indeed, only this morning, I have been out and bought components and materials for my next DIY project.  More on that in future posts!
I decided to turn up a day early to give myself as much opportunity as possible to get some observing done.  This proved to be a good idea given the forecast for the main arrival day was for rain on and off throughout the day and evening.  With this in mind, I had packed plenty of different kit in the van which would keep me occupied for the weekend.  Boxes of electrical components, ongoing DIY projects, books and even the guitar made a rare trip out of the house.  I managed to get some observing in on the Friday evening and was pleased to observe the Great Cluster in Hercules, the Ring Nebula and Mars.  This was the first time I had chance to observe Mars for some years, so I must have spent 20 minutes or so looking at it alone.  Clouds came and went, but eventually covered the sky.

Arrivals Day...
Arrivals day at camp is brilliant.  A chance to catch up with friends from past camps, and just as important, to make new friends. This year, next to my pitch, I was fortunate to be joined by Raoul.  A first timer to camp, but not new to the hobby.  He brought with him various DIY projects including an array of Arduino based ideas that he was working on.  Perhaps the most impressive of his projects, and the one which I would consider trying myself, is a meteor detector which can detect the passing of meteors through the atmosphere regardless of weather or day light.  He demonstrated what was possible, showing us some recent recordings captured during the Perseid meteor shower.  Showers and cloud allowed me time to work on one of my own projects, and to solve an issue of dew bands not heating up when used with my DIY dew band controllers.  So, it was out with the pliers, screwdriver and soldering iron in the tent as the rain pattered down onto the tent roof. 

Day 2...
Sunday morning started early for me.  Not being able to train my body clock to simply allow me to have a lay in, I was up and about at around 6.30.  After the previous days rain showers and cloud, I was greeted by occasional patches of blue sky and some warm sunshine during breakfast.

Sunday is always a day I look forward to the most at camp.  It's the day when everyone moves down to the local village hall, and to the pop up pub 'The Spiral Arms'.  It's also the venue for the much anticipated pub quizzes and talks which are always popular and never disappoint.  This camp, the guest speaker was Libby Jackson who spoke about women who work in space.  Libby is author of 'A Galaxy of Her Own: Amazing Stories of Women in Space''.  A collection of stories about women who have made massive and significant contributions to space science and space travel throughout history.  It wasn't until Libby started talking about her research and her book that it hit me exactly how under recognised these women have been by the history books.  Her talk was incredibly enlightening, and now that I have returned from camp, I look forward to reading her book to learn more.  There are so many events that have happened in human space history that would never have been achieved without some significant and important contributions by these women, that it baffles me why they don't get the recognition they rightly deserve.  Libby's talk was by far the highlight of my camp and one that I will remember.

Back in 1973, the famous Welsh poet, singer and writer, Max Boyce wrote a poem about a legendary event in Welsh rugby history when Llanelli beat New Zealand 9-3.  But the event wasn't entirely about the win itself, but more that the pubs ran dry!  Well, at Astrocamp 13, Welsh history was to repeat itself once again, as indeed, the pub ran dry.  It made the final quiz of the day, dubbed 'The Masters Of The Universe' quiz all the more important as entrants were playing for a case of beer!
During the day on Sunday, a wave of optimism washed through camp as rumours spread of a window of clear sky that evening.  As people headed back to the campsite from the Spiral Arms, attentions turned to getting prepared for the potential of an evening of Astronomy.  I decided to set up my refractor and imaging equipment.  At first, given the forecast window of clear sky was quite short, it might have seemed a bit of a waste of time.  However, as readers of my previous posts might know, I have recently bought a new mount and I wanted to get some more use out of it.  I seemed to have had a good run of luck with regards to guiding and setting this mount up for imaging runs, so I wanted to confirm to myself that this wasn't by some sort of accident.  So, the only way to prove that my recent results haven't been down to pure luck is to ensure that everything is repeatable.  So, it was pleasing to see that once again, I was able to achieve a good guiding graph using PHD2.  But, perhaps even better, I was please to be able to demonstrate to some fellow campers the ability to polar align using Sharpcap Software, the ability to slew the scope to various targets using Cartes du Ciel and finally, to set up an imaging run.  My luck soon ran out though.  By the time I had achieved everything I needed to do and I was ready to start imaging, I only managed a single 2 minute exposure of Andromeda before the clouds rolled back in bringing proceedings for the evening to a close.  I'll still chalk that one up as a success though.

Should I Stay or Should I Go???
Monday is the hardest day of camp for me.  Knowing that the end of camp on Tuesday is approaching, almost straight away, me and many other Astrocampers look to the weather.  The thoughts of the pending journey home.  This year, the forecast for the last night of camp was for very little observing opportunity because of cloud, and the potential of rain coming through during the early hours of Tuesday.  The possibility of dropping a bone dry tent and dry kit and then not have the problems of needing to dry everything out always makes the choice a tricky one.  Monday is the day of high tea on the common area of the campsite.  Everyone from camp gathers together to enjoy their last afternoon together.  It's a point in camp that I look forward to, but alas one that I did not attend this time around.  I made the tricky decision to bring my stay at Astrocamp to an early close.  Not that I rushed to get packed away at all.  I don't have much of a journey home.  So, at a leisurely pace, I set about getting everything cleaned up and helped out others where I could before loading the last of my kit in the van before heading home.  It's always sad to leave, but leave we all eventually must.

Looking forwards...
April 27th 2019 will see Astrocampers gather once again in Cwmdu.  With bookings due to open in around a months time, it's already a date put into the calendar.  This camp, I had a walk around the site, looking at the sky from different pitches to ones that I would normally consider.  On a small site such as the campsite in Cwmdu, you don't have a lot of choice, so it's often a race to get to the prime pace you want to, but I will be there, finger on the button and ready to book.  Already, I'm looking forwards to seeing my friends again, making new ones and swapping stories about what we have been up to over the Winter.
This camp has been a great reminder of what I missed back in the Spring, but at the same time, it's like I never left.  Putting on events such as this takes a team of very dedicated people, and it's only right that they be appreciated.  So, firstly, my thanks to Libby Jackson for coming to speak to us, and for providing me with my highlight of the whole camp.  My thanks of course has to go to the team at Awesome Astronomy, Ralph, Paul, John, Damien and Jen.  Every camp means another brilliant and memorable time to be had.  My thanks also to my friends and neighbours, old and new at Astrocamp 13.  You put up with me and always have time for me, which is truly appreciated.

Why I'll be at Astrocamp 14...
Many comparisons are made during various star parties between organising groups and venues.  Some of these opinions are formed on the experience and views of others by people who have never been.  I have always said that I intend to visit a selection of different events around the country.  Earlier this year, I attended the Spring Kelling Heath star party in Norfolk.  That is a huge event with hundreds of attendees spread across a very flat and well appointed site, with generous sized pitches.  Being in the East side of the country, it could also be argued that there is a better chance of having more observable nights, with slightly better weather than is experienced in the mountains and hills of Wales.  So why not return?  The reasons are numerous.  What Astrocamp brings to the table is what many perceive to be a much more friendly atmosphere.  I went to my first Astrocamp on my own several years ago, not knowing anyone.  By the end of that first camp, I had made friends for life and had been left with no doubt that I would return.  Undoubtedly, the key reasons for this were the smaller site which makes the whole event more intimate, the Sunday in the Spiral Arms and perhaps more than any other, the common area in the middle of camp.  This is the place to meet, to share stories and views through the eyepiece, and in the event of a cloudy evening, chew the fat over a couple of lemonades.  Would I go back to Kelling?  Not for a star party, no.  Astrocamp however is a completely different experience.

Thanks for reading!