Summer Triangle Widefield Imaging – First Attempt

At mentioned in my last post, I ended up with 263 frames of the Summer Triangle. I thought I’d have a go at processing one of these to see if I could get more detail out.

So here’s my starting image.

I hadn’t realised quite how bad my light pollution was until I saw this.
It’s a 30 second exposure, sunlight white balance at ISO400 taken on a Canon EOS400D with a Sigma zoom set at it’s widest 18mm focal length.
faintest stars you can see here are about magnitude 4.
I then tweaked it a bit in photoshop, adjusting levels to bring out fainter stars up to about magnitude 7. I removed the colour cast as best I could, although I think I went a bit too at as it’s quite blue now.

Now I know this is far from perfect. It’s a first attempt and I can see quite a few problems.
Stars aren’t quite in focus. I’d focused manually and it’s difficult to know in the dark through the camera eyepiece.
Next time I’ll lock the mirror up to prevent that causing a bit of shake.
Exposure is only 30 seconds but I don’t think I can do longer without the stars blurring with motion. I could, if I put the camera on the telescope’s mount. There is a piggy back mounting screw.
I think I need to really up the ISO, perhaps up to 1600 to captured the fainter stars. I’d held back because I thought I’d end up overexposed with all the light pollution. I think though, that I can fix that with levels in processing.
I need to investigate stacking multiple images too, as that seems to be how many people do it.

Finally I annotated the final image in Skitch on the iPad to identify the various constellations and stars. That was an fun and educational thing to do. I hadn’t noticed the small constellation Delphinus creeping in just below Cygnus for instance, and on zooming in and around the shot, I also noticed Collinder 399, Brocchi’s Cluster aka the Coathanger sneaking in.

Observations – Saturday 4 Aug 2012

Location: Worthing, in-laws back garden
Weather: mixed cloud. Moving quite quickly so changing opportunities. Dry.

22:00-ish First light on the new Skywatcher 9×50 RACI finder scope. It’s great-so much easier to use than RDF. You can see so much more. In fact I’m thinking it’s worth taking away with me when travelling. Even though i know where it is now, I was on the Ring Nebula, M57 within minutes.
Yeah, yeah, I know M57 again but I wanted to see if a couple of other factors improved the view. Firstly there is far less light pollution in Worthing, their street lights aren’t so orange, and being on the coast there is half the amount of light anyway. Well until the moon came out. More on that later.
Secondly I’d been to Sussex Astronomy Centre and bought a new eyepiece. I got a Skywatcher 6mm ultra wide eyepiece with 66deg APOV (apparent field of view).
M57 was really clear in it. I could really see the ring and the darker centre. I could also see that it wasn’t uniform all round.

Father in Law came out to see what i was up to at this point, so I moved on as this is perhaps a tricky target if you’ve not looked through a telescope before. So I showed him the double Albireo in Cygnus. The difference between the brighter yellow and it’s blue companion was very pronounced.

23:00-ish Then my Mother in Law came out, together with a lot of cloud so all I was able to show her was Vega directly above in Lyra and a few stars around it.

23:30-ishThey went in and my Brother in Law came out as the moon was clearing the trees. About two days past full. It was washing out much of the sky and reflecting off clouds and I think the sea a couple of streets to the south.
Had to put the moon filter on to cut the brightness and we went straight for the 6mm. Seeing was good. Hardly any rippling. Put the tracking on and observed along the terminator. Highlights were Mare (Lunar 100 #10) and the adjacent Cleomedes crater and a chain of 4 craters including Langrenus, Vendelinus, Petavius and Furnerius. Of these Petavius (Lunar 100 #16) was the most impressive with it’s central peak.
Takes my Lunar 100 count up to:
Observed 3/100
Imaged 8/100

24:00-ish. popped the Asda webcam into the eyepiece holder and fired up Sharpcam on the netbook to snap a couple of shots of the moon.

Mare Criseum and Cleomedes crater.

Craters on the terminator. You can see the central peak in light and shadow on Petavius

Observations – Sunday 29 July 2012

Location: The Back Garden
Weather: Clear skies, bit chilly for the time of year.

22:00 For the first time in ages I saw the Moon. I could see it peeking through a gap between the trees. Got the scope out and set up with some urgency as I knew there wasn’t much time. By the time it was set up it was just coming out from behind the fir tree and I’d probably got about 15 minutes before it went behind the next one. It was very low, probably about 30deg. The plane of the ecliptic is quite low during summer.
The Moon was just over 1/2 phase so I looked for interesting features near the terminator. I picked on the crater Gassendi on the northern edge of the Mare Humoroum. It’s a great looking crater with a central peak. Directly opposite on the southern edge or Mare Humorum is a flooded crater, the baylike Doppelmayer.
The image below is a screenshot from the Moon HD app on the iPad.

I’ve started doing the Lunar 100 and Gassendi is #13 on that. Sounds daft but I’m starting from scratch as as I haven’t seen the Moon for ages and that takes my tally to 2/100 observed.
And with that it was behind the tree again, but not before I got A out to take a look. People are always impressed to see detail on the moon through a scope.

22:15 I turned my attention next to the Summer Triangle, and in particular the constellation Lyra. Took a look at the double star epsilon Lyra. It’s actually a double double. I think I just about managed to split them both with a 10mm eyepiece.

Last weekend I bagged my first Messier object, M57, the Ring Nebula. I’m trying to spend time on each object rather than spot as many as I can, as quickly as possible, so I’ve been returning to it in my observations this week. Part of my reasoning is to familiarise myself with and to learn an object better by focussing on a small area of the sky. The other reason is that living in a city I have to contend with light pollution, street lights overlooking my garden, surrounding buildings and a lot of trees so the area of sky available to me is pretty much overhead and a bit to the north and a bit more to the south. This limitation can be frustrating but also means I can’t just go jumping all over the sky.
Really getting familiar now with Lyra and after my first attempts at star-hopping that took about 2 hours to spot, I was able to find M57 quite quickly. The Ring Nebula was quite difficult to see this evening. It was starting to get a bit hazy and the seeing wasn’t great – a bit ripplely. It was more obvious through the 25mm. I was able to get a cleare view sometimes with the 17mm Plossl but only with a bit of averted vision or when I tracked across the region. Then it would kind of pop in and out of view. It’s a fine sight, like a smoke ring. At first I wasn’t sure I’d got it but after returning several times in the last week, it’s a familiar and recognisable sight now.
I also tried a light pollution filter. Whilst it seemed to take out some of the orange glow, I’m not sure if it made the nebula clearer or not. But then I’m not sure if it’s supposed to enhance the view of a planetary nebula such as this.

Whilst moving away from and returning to M57 during this session I made myself familiar with the stars around beta Lyra, Sheliak, and gamma Lyra, Sulafat. M57 lies between these two.
I’ve just started playing with Sky Safari (more on that in a later post) so have matched what I sketched very poorly with what I was seeing around each of these as below.

There’s a line of three stars leading away from Sheliak, and Sulafat forms a triangle with two other stars.

23:25 It was getting cold by now. I was about to pack up and then noticed the Moon was just peeking through a low gap in the trees to the SSW. Took a final look at Gassendi. Noticed a further smaller crater on the northern wall of Gassendi. This was Gassendi A. Together they make what’s known as the diamnd ring.