Saturday, 8 October 2016

Another 3 for 1 update!

It's been a pretty hectic couple of weeks since coming back from AstroCamp in late September, and things don't look like their going to ease up any time soon.  Next week, I'm off on my very first astronomy holiday to France, although it is full moon week, so quite how much worth while observing will be done in debatable.  Nevertheless, the break is what is needed at this moment in time.  The astronomy will be an added bonus.  I've had a few sessions since returning back from camp, so this is the summary of what I've been up to.


Straight off the back of AstroCamp, I was back outside the night before I was due to return back to work.  The conditions were favorable, although I needed to be careful not to get carried away with a late night.  This was to be a quick session, out the back garden with the SBT.
First up was the double cluster in Cassiopeia followed by a quick slew of the scope around to the Whirlpool Galaxy in Canes Venatici.  Many people associate this galaxy with Ursa Major, and, though it is very close, actually, it is within the boundary of Canes Venatici.
My next target for the evening was The Ring Nebula, and with the prevailing excellent observing conditions, I was able to observe the companion star next to the nebula with relative ease.  If found on this occasion, it was best observed with the 12mm BST eyepiece and UHC filter.
Then, for a last target for this quick blast of a session, I went to the Veil Nebula.  Here, I spent a reasonable amount of time comparing the views I was getting when on camp, to what I saw from the back garden.  Probably unsurprisingly, the views I had from camp were better.  I don't necessarily put this down to the overall barker skies, or better seeing conditions, but probably more to do with my night vision being disturbed by the occasional light being switched on from the neighbors as they went about the normal business. Nevertheless, I was still able to see the Eastern and Western Veil with the 40mm eyepiece and the UHC filter.  Notably though, it was harder to see the broom end of the Witches Broom, and the region known as Pickering's Wisp wasn't visible to me at all.  Still, it was great to be able able to observe it again though.


At this point of the season, it's really hard to let a clear night go to waste.  Though tired, I wanted to be able to get out and do something, so I set up the AVX mount and connected everything up that I needed to try and collect data for another image.  I decided that it would be worth a crack at the Witches Broom, part of the Veil Nebula in Cygnus.  For some reason though, it took several attempts that evening to get my alignment right.  I think it could have been something to do with a slight shift in the mount as it settled down into the soft soil of the lawn.  In the end I got it to an accuracy which was OK.  But then I faced another problem.  I found it hard to achieve an accurate focus using the meter readings on Backyard Eos.  The main issue was that I couldn't get a suitably bright enough star to appear in the field of view.  Time was getting on, so I just went with a bit of trial and error and best endeavors.
I took two sets of Light frames, so, in theory, I could then compare the difference with two final images.
Set 1:
Light x 20 @ ISO 800 for 90 seconds

Set 2:
Light x 15 @ ISO 800 for 60 seconds

And then:
Dark x 5 @ ISO 800
Bias x 5 @ ISO 800

I'm still trying to get a suitable image out from either set of data.  The focus isn't brilliant, but I can get an image to come through showing some of the detail in the nebula.  Unfortunately though, in order to do this, the image turns really 'noisy',  Very grainy in appearance which kind of spoils the rest of the image.  I will continue to try, but I might have to put that one down to experience.  The imaging process can't be rushed, and at the end of the day, I could probably do with at least twice the amount of light frames and dark frames.  Even to the point of running to an hours total of lights.  We shall see!


I decided on a visual session because it’s quicker and easy to get going with the SBT rather than carry out alignment processes required for astrophotography. It was quite a busy night!
I started off with a favorite for this time of year, the Owl Cluster in Cassiopeia. Often, a degree of imagination is needed to establish why an object, or a target is named as so, but the Owl Cluster simply leaps out at you, and the shape of the owl with its bright eyes staring straight back down the eyepiece at you is very easy to distinguish.  Next, staying in Cassiopeia, the Double Cluster NGC 884 and NGC 869.
While on the theme of clusters, I moved the SBT to point toward M71 in Sagitta. It’s a small cluster in comparison with the ones I had observed earlier, but with the help of the 12 inch mirror in the SBT I could see the small tight cluster nestled in among several brighter surrounding stars.
Clusters seemed to be the topic of the night because the next target was an open cluster in Cygnus, M29. This is also known as the Cooling Tower, and though reasonably easy to see and locate, it is one of those targets that I find hard to understand how it got its name.
It was time to move onto a nebula, and another favorite for this time of year. The constellation of Lyra is almost at zenith at this time of year, so I attached my UHC filter to the eyepiece and went off in search of the Ring Nebula, M57. Being straight up above us, it means that we can observe it through the thinnest part of the atmosphere at the moment, giving us the theoretically best views we can get. Chopping and changing between eyepieces, I wanted to have a go at finding the central star to the nebula, but alas it wasn’t to be this time. It’s one of the few targets where the colour of the object comes through visually. Especially the Deep Space Objects. Most of them initially appear as grey smudges, the Ring Nebula is different and always worthy of searching out.
For the final target of the evening, I chose something that I don’t often search for on purpose. Some people love observing individual stars, be they variable stars, double stars, star associated with nebulosity etc. but they are not something I search out specifically. The target was the variable star, Herschel’s Garnet Star on the edge of the constellation of Cepheus. It stands out easily amongst its neighbours and is relatively bright. It’s a beautiful orange colour, and at just under 6000 light years away, comparatively speaking, quite close!

That's about everything up to date.  There is a potential for some reasonable weather at the start of the working week, so I might be able to squeeze in another session before we go on holiday.  Failing that, the next time I post, it could well be from France!  Until then, clear skies!

No comments:

Post a Comment