Clear night in Wales at last; 27.11.2013

[dawson]

PDF version with integrate images here (https://dl.dropboxusercontent.com/u/1673286/Wednesday%2027th%20November%202013pdf.pdf) text and hyperlink below:

 

Wednesday 27th November 2013, Trawsfynydd, North Wales

 

Well, it's been a relaxing week away in North Wales, but not had much astro-action due to the weather. Imperfect day-time panorama of the location:

 

 

All the forecasts for last night were gloomy so I'd made tea, had a glass of vino and put a load of logs on the fire.

 

I'd left the mount and scope set up outside since I'd arrived, under various ground sheets and GreenWitch bags, and I'd done an OK polar alignment on the first night, so it was ready to go at the drop of a hat.

 

It was about 6pm and I'd been outside an hour earlier and there had been dense cloud sitting above the house, despite signs earlier in the afternoon it might be breaking up. However, at 6pm there were breaks in the cloud again, big breaks! Polaris was visible and here and there other bright stars, which I was guessing were Deneb, something in Pegasus, and maybe Castor on the distant horizon.

 

I was quite surprised and think I uttered a swear word which might have shocked the sheep, but dashed back in doors, and put some better clothes on (monkey onsie and other comedy paraphernalia).

 

Powered the mount, and re-checked the polar alignment; I altered it a bit but I can never seem to get Polaris to follow the circle nicely, it always sits on the outer circle one side, but is a smidgen away on the other. Anyway, went on to do a star alignment. Slewed to Deneb but by the time I go there it had gone again. Hunted for Castor in the list of alignment stars and it wasn't there (though it was only just hovering above the horizon). More cloud rolled over so I thought I'd go and have tea and try again later.

 

Sure enough 30 minutes later it was as clear as a bell. There was plenty of star twinkle, but I could see so much!

 

I was in a blind panic.... Should I set up and do some widefield / star trails, or use my time to align the scope and look at stuff / image some DSO stuff for a laugh whilst waiting for Jupiter to get higher (the main target of my evening).

 

I did a nice three star alignment first on Vega, Altair, and Capella, the first three stars the handset listed; it's so nice just having a mass of open sky and having the choice of using any star it suggests rather than fighting with trees and houses in the way. I didn't use the reticle eye piece and just roughly centred the stars in the 1.25" 32mm EP. The hand set said my Maz and Mel errors were about 9 arcminutes each, which I was pleased with (for what it's worth).

 

I've got a new DSLR, a 6D and wanted to have a play with that to see how sensitive it is compared to my 600D. So I loaded the 6D onto the back of the scope on the flip mirror; I love my flip mirror, it's so useful. I went to look for M57 (ring nebula) and sorted out focus with a Bhatinov mask and live view on a nearby star. I did some test shots and thought 120 seconds was about the maximum I could go before I saw obvious star trailing. So, whacked the ISO up to 2000, and left it doing some 120 second subs of M57 while I went to set up my other DSLR to do some widefield.

 

I set the Canon 600D up on a tripod and pointed it West towards the Milky Way, behind the house so away from any of my stray red light from my head torch; the back of the house is dropped below the adjacent field, so the fence offered a nice foreground. Put a hand warming pad on the lens and set the focal length to 10mm (not full frame so 16mm I guess), opened the iris up to maximum, and played with the ISO to see what was acceptable. I'd planned to leave it on ISO 1600, but for some unknown reason I left it on 6400! Set it off doing 20 second subs, with a 1 second pause between.

 

Went back to the scope and thought I'd have a look at M1, the Crab Nebula as this was reasonably high now and again images of it always inspire me. The GOTO was working like a dream, which is a good job as I wasn't exactly sure M1 was in relation to the two horns of Taurus! I could see a faint smudge, but I was using the mirror in the flip mirror and a low quality eye piece. so I got the image on the DSLR sensor and decided to let it run for a bit while I admired the sky with my eyes; I left it doing 120 second subs.

 

Popped in to a make a cuppa and then came back outside and had a sit down and a look around.

 

WOW! I'd been so absorbed in getting things done I hadn't taken the time to really look around me. This place is reasonably dark, there is a village a mile or so away, but the nearest big town is 5-10 miles. There is a main road again about a mile away, but luckily conifers baffle much of the stray light from traffic.

 

The main WOW was the Milky Way. A massive band across the sky, brightest in the West around Deneb, then arching up through Cassiopeia which was at about the zenith (it difficult to know where it was exactly as there were so many stars). The Milky Way then continued over to the East where it was less obvious as it passes adjacent to Orion. I sat for a few minutes and just thought about what that band of star represents; us looking back into the centre of our galaxy. It really did give me a sense of awe at how big just the Milky Way is.

 

Orion was now above the horizon, and I could count 25 stars within the main asterism. It was clear that Betelgeuse was yellow, and Rigel blue-white. I'd not seen the colour distinction so clearly before. Aldebaran was also so clearly a yellow star. And the Hyades were like I'd never seen them before, a great clump of stars which must be washed out in my usual light-polluted sky.

 

Following the line of Orion's belt, through Aldebaren I came to the Pleiades. As hard as I tried, I could only clearly see six of the sisters, I tried to convince myself I could see a seventh very close to another, but I think that was wishful eye sight (though my glasses are filthy as always). On that note, I'd forgotten to bring my old-man glasses string so I can take my glasses off and leave them dangling around my neck when looking through the eye piece; such an annoyance to keep putting them in my pocket with all the other astro-junk in there, or dropping them on the floor and then unable to find them!

 

Looking to the west of Orion past Procyon in Canis Minor and a little higher, I could see two stars and something fuzzy between them and to the east. This isn't an area of the sky I know at all yet, so I was bemused. I went to get a star map and worked out it was Cancer (my star sign incidentally), and the fuzz between them was the Beehive Cluster (M44). I wish now I'd brought a pair of binoculars with me, though the car was already rammed to the gunnels.

 

At this point I went to check on the widefield project, and the camera wasn't taking any images! I'd set the remote up incorrectly so it had only take about 20 subs, not the 9000 I wanted So, reprogrammed the remote and got it going again after giving the hand warming pad another good shake up.

 

The scope had now been pointed at the Crab Nebula for about an hour so I thought I'd have a look at some other stuff through it. It was then I realised how wet the night was; the remote for the camera was saturated, and tripod pretty wet too, but the sky was still crystal clear with just twinkle.

 

I wondered how some of my favourite DSOs might look on my new DSLR via the scope, so had a quick play at going around the sky and taking short single exposures (60 seconds or so) on maximum ISO to see how they would be framed. On the whole I think they are framed nicely, and if I ever get around to being able to increase my sub length to 5 minutes I think I could get some simple DSO images I'd be really pleased with:

 

Dumbbell nebula: one of my favourites generally.

 

M13: a pretty magical looking glob.

 

M33: maybe too big for my kit, but still a fascinating looking galaxy.

 

M42: much too large for my setup, but as it's so bright it's difficult to ignore.

 

The Owl Nebula: what's not to like about this cutie.

 

Eskimo nebula: fascinating bright little object like the Saturn Nebula and the Blue Snowball.

 

I then had a bit of a nose around some objects visually, M81, double cluster, tried to see if I could split Castor as I'd read about it earlier on in the day, and I managed to see Castor A+B and C (not my image below, though I did get a shot of it):

 

http://astrobob.areavoices.com/files/2012/02/Castor-C-400x261.jpg

 

I then remembered a thread on SGL which someone had started asking people to show what they could achieve in just 30 minutes of imaging. So thought I'd have a go. The Little Dumbbell was pretty much at the zenith, so thought I'd target that. Sorted out focus (on my knees as the 6D doesn't have a flip out screen unlike my beloved 600D). Again thought 120 subs was going to be my limit, and left it alone.

 

By the time I'd had a cuppa and the 30 minutes of imaging M76was up, it was approaching midnight, and I thought I should get on and try and image Jupiter. As I was getting ready for this a load of mist rolled in, though again the sky remained clear, but all around me was like a scene out of Hound of the Baskervilles! It passed after about 20 minutes.

 

I connected the ZWO ASI 120MC to the flip mirror on a 2x Powermate, and slewed to Jupiter. Centred and updated the handset with the location so I could easily find it again. Slewed over to Pollux to sort out focus with a Bhatinov, then back to Jupiter. Using SharpCap2 (thanks for the tip off Rob) I centred Jupiter on the sensor and reduce the area of interest down to 640x500 or so. The bands were very clearly seen, though not sharp, but I've never seen them sharp in live view mode. I could see there was a red spot, hopefully the GRS, but I'd not checked if it was in transit or not. I noticed a load of artefact, likely dust bunnies on my sensor, so I increased the area of interest a bit and planned to do some manual 'dithering' to try and offset the dust bunnies in processing. I did a fair few runs of 1.5 to 3 minutes, and altered the exposure time and gain, and on some runs managed to get nearly 50 frames per second.

 

By now, everything was wet, including the laptop and my coat and monkey legs. So parked the scope at the home position (first time I've parked the scope) in case there were clear patches another night, and shut down. Brought all the other kit inside to dry off, and collected the widefield camera which was also dewed up to the max!

 

I decided I was still not tired so would have a play with processing, but that was a mistake, I should have just gone to bed as I was more tired than I thought and was getting easily frustrated.

 

Anyway, I had a look at the Jupiter data this morning, and there are serious issues. I think my focus was very much off, the dust bunnies are a serious problem, and from an SGL thread, I think my focal length was far too great for the conditions / camera. But this is all a learning experience:

http://stargazerslounge.com/topic/200749-jupiter-help-please/

 

I've managed to extract a star trail from the widefield project which I like, but really do need to sort out a longer lead so I can leave a dew and on the lens well away from the dew controller which is on the scope 20m away:

http://www.eastmidlandsstargazers.org.uk/topic/6414-star-trail-north-wales-27112013/

 

The two DSOs I had a play with imaging are OK (again this was never for submission to the S@N magazine, just to see what a dark sky, short subs, and long focal length can achieve). Despite the lesson I had off Leigh on Photoshop, I still don't really get it, so I might have to bribe Ibbo to give me a one-on-one at some stage; it's also very clear I need longer subs than 120 seconds. I also forgot to do darks or flats:

 

M1:

 

M76:

 

So, in all, I had a wonderful night. Really enjoyed myself, and as always learnt a fair amount from the experience and from the aftermath.

 

North Wales is lovely, it just has a lot of cloud. I think my next astro-break may be to the East Coast somewhere.

 

James

 

[BAZ]

You got a good bag of objects there James, Iam really glad you got some clear sky at last. I like M76, you don't see that one often.

Great report, and very entertaining. Thanks.

[Sheila]

well done James,  

 

sorry to disappoint though, the SGL thread included set up as well  thats why i posted i could not put my kit together in 30

mins never mind get an image

[T A WOW]

Cracking read that. Some really good pics too. I love the star trail.

You should try Cornwall for dark skies, down near the lizard. Zero LP.

Is the colour in the pics natural or a processed effect?

[catman161]

Awesome report JD and some great images too, well done

[dawson]

Set up as well!!!! I better pull my entry before the astro-police catch me. I knew it was a stupid thing for me to do.

Tobias[the elder], it's natural colour on the star trail, i often find my skies look brown'ish, must be a combination of factors including some light pollution. All the star colours are as they appear on the sensor, and there was no light pollution filter in the camera.

Jd

[+RonC]

Good read that James, the learning curve seems to get steeper the further you go!!

Why such high ISO's though, adds a lot of noise to the image, I was looking to double my exposures with guiding and reduce the ISO to maybe 400? I usually leave it on 800

for my imaging, interesting!   

 

Cheers

Ron

Edited November 28, 2013 by Ron Clarke

[dawson]

None of the above images are for anything other than messing around. Mostly i wanted to see how they would be framed with my current set up, so just wanted to see the bulk of the image in 60 seconds, so went for ISO 248000 or whatever it is.

Doing 60-120 second subs at f/15 results in next to no data for most of these objects at ISO 800 or 1600.

If i can ever get to 5 minute subs i think i could then start to collect meaningful data and drop the ISO to three digits.

I should have made it clear these images were just playing around whilst i waiting for Jupiter to get high and for the "heat of the day" to disperse and minimise the shimmer whilst imaging Jupiter.

I'm still waiting for the big moment you announce your are guiding on all cylinder and to see you in S@N magazine

I'd just like some pretty images for my office and for facebook!

James

[+RonC]

Ha ha, I'm just waiting for a clear night now! Focus and mounting sorted and PHD sorted (I hope!)!

Wait and see!! Sounds like you need a week at Badger Farm!!

[red dwalf]

Looks as if your having a great time James

[Allan the Plumber]

Great Images James