Deep Sky (SBIG ST4000XCM), 2011

2010

 

After days of snow/cloud/bright Moon I actually had some hours of clear dark sky on 5th January 2011.

BUT.... The seeing was appalling. Using the 12" at f10 the fwhm was around 8.5 and the guide star was jumping all over the place. I need at most fwhm of 4 to be any good, so that was a non-starter.

So. Go for wide field. And a couple of nights earlier expecting clear skies (but the forecast was wrong!) I'd fitted a 200 mm camera lens to my one-shot colour SBIG ST4000 XCM with Kemble's Cascade in mind. For anyone who isn't familiar with it, it's a grand binocular object in Camelopardalis (earlier imaged in 2004) a cascade of stars splashing down into NGC 1502. Although it was by now well past the meridian, it was still quite high, and a couple of hours produced this (cropped vertically for better framing). 10 x 10 minutes at around f6 (f4 lens). Full size.

Although the asterism is plainly visible in binoculars, it is not so obvious in the photograph. But a light touch of artificial diffraction spikes, courtesy of Star Spikes Pro and it stands out nicely. Full size

This image appeared in the March 2011 Astronomy Now magazine and in the March-April 2013 Popular Astronomy magazine.

Getting too low for any more data, but on the other side of the sky Coma Berenices was riding high. So on with a shorter lens (135 mm, f2.8 at f5.6) and I managed 8 x 10 minute subs before the clouds returned. Full size.

Makes a change from the small stuff. If you look up the left hand side of the Coma image you can see NGC 4565 and higher up NGC 4559, both of which I've imaged close up in the past. Puts the sizes into perspective! 

 

 

 

 

 

 

The BBC 'Sky at Night' programme broadcast at the beginning of February 2011 put out a request for images of Orion. I submitted images, some of which were used along with old favourite Milky Way from La Palma to show the Scorpion - Orion's nemesis in mythology!

But I didn't have a suitable image of the whole constellation, and bad weather prevailed for the 'window' available to submit. However a clear night on 30th January gave me a chance. I had to scrap some subs due to passing cloud and light pollution, but here is the result from my back garden. 13 x 15 minutes, SBIG ST-4000XCM with Tamron 17-50 f2.8 zoom lens at 30 mm and f5.6 . Unguided on EQ6 Pro mount. Full size (1.2 MB) Spikes added with Star Spikes Pro to enhance the main constellation stars.

Despite combining many frames, still a hint of the power lines which cross my South field of view. Maybe I'll try again from a darker unobstructed site.

This image is featured in the Jodrell Bank Radio Telescope introduction brochure.

The second frame taken, although not used because of the trail, showed what at first looked like a meteor. But on closer examination after processing probably an Iridium Satellite because the trail extends faintly for the whole frame. And there is a second trail almost paralleling the first. The start of the 15 minute exposure was 19:05.00 on 30th January give or take a couple of seconds. Full size

And a visit to the Heavens Above site confirmed that they were indeed Iridium satellites, 91 and 52, with almost identical positions and only 67 seconds apart - apparently 91 is a spare with 52 active. Details here.

A few days later I managed to fit a Hydrogen-alpha filter (Baader 7nm) into the camera lens, and before the weather deteriorated acquired a single 15 minute frame, binned 2x2 to prevent Bayer patterning from the one-shot colour chip. Although desperately noisy, by the time I'd played with it, dimmed and blurred the stars it was worth a try at blending with the Red channel in the original image. And it's a bit better - the nebulosities are brighter and the star colours haven't been affected. It would have been nice to get several frames, but the way the weather was looking, not very promising. And by next month it's getting too late in the year. 

Anyway the dratted power line shadows really urge me to make a completely fresh start from a different site. Another time. Full size (1.3 MB)

LATER. Look closely at Betelgeuse and you can see a faint bell shaped dusty outline surrounding it. This is known as Pickett's Bell, Named after Tom Pickett who posted an image on Facebook in November 2015. See here.

See also the Canon 350D version

The 2011 Kielder Forest Spring Star Party took place over the weekend 5th/6th March. I was staying a few miles South at Calvert Trust, and unfortunately the Saturday night was clouded out. Sunday and Monday nights saw a few hours of clear skies, but with thickening freezing mist and occasional passing clouds.

I only tried to image one subject, using my SBIG ST4000XCM on M101 through my Meade 127 refractor. The hope was to well define the faint extensions, hence the use of the 127 for the wider field of view. But the haze affected the contrast, so not as clear as I'd hoped. Heigh Ho... Anyway here it is, 15 x 20 minute subs. Full size

Postscript. I later (13th March) used the colour information with a deeper luminance from the ST-10 camera . Here.

      

In 2016(!) when looking for targets for my QSI683 camera I discovered I had imaged the disturbed galaxy NGC3239 (Arp263) in Leo with the ST4000 camera, and never posted the finished image! So here it is in its correct time slot. It precedes a supernova I imaged in 2012 with the QSI camera and also overlooked until 2016!! 18 x 20 minute sub frames taken over 23rd March and 4th April 2011. Camera on Meade 12" at f7 with SBIG AO unit. The crop of course shows the galaxy prior to the supernova.That image is here.

 

Full size

A long time since I imaged Messier 51 - the wonderful 'Whirlpool' galaxy in Canes Venatici. There's a really bright guide star to one side, perfectly placed for my ST-4000XCM on the 12" LX200ACF with 0.7 reducer. So I gave it some attention on the night of 4th April 2011. 9 x 20 minute subs, darks and flats applied. I would have liked more, but the skies clouded over, and it was anyway slightly hazy, so I didn't pick up the outlying 'mist'. Maybe 20 x 30 minute subs next season.... (And see Supernova below)

This image featured in The Sky at Night BBC TV programme, August 2012

Full size

After a few days of very welcome cloud and rain, with twilight and a waxing Moon on a clear night on 8th April 2011, I decided to try for a decent image of Albireo, the beautiful double star in Cygnus. ST4000XCM of course to avoid blooming, and two different fields of view - one with the 400 mm Canon lens and one with the 12" Meade LX200ACF at f 10 (3m fl). Seeing was very poor, but the close up responded reasonably well to deconvolution.

Wide field 22 x 1 minute subs, close up 30 x 1 minute subs.

Full size wide field

Full size close up

 

NGC 188 is an interesting open cluster situated in Cepheus, only 5 degrees from the North Celestial Pole. There are several bright stars in the vicinity,, so this was one for the ST4000XCM. Also quite large, so the Meade 127 refractor was used for this image. 9 sub frames x 10 minutes (with AO-8 guiding) in the early hours of 21st May 2011. Astronomical twilight.

Full size

Another shot for the ST4000XCM on the Meade 127, this time a wide field of the well known Messier 63 - the Sunflower galaxy in Canes Venatici. Again early hours due to limited darkness, only astronomical twilight, this time 23rd May 2011, and only 6 frames x 15 minutes. Revisit planned for early 2012!

Full size

I was out imaging on 3rd. June, getting the above test image of M63 following collimation problems with my Meade 127. At the time I hadn't heard about the supernova in M51, or of course that would have been my target! When eventually it came to light ;-) the clouds returned, and them along with a bright Moon on occasions when the clouds thinned put me well out of action. But a couple of reasonably clear nights on 28th and 30th June 2011, so at last I got SN 2011DH

SBIG ST4000XCM on Meade 12" LX200R at f7. 8 x 10 minutes and 6 x 15 minutes. Of course at my latitude of 55 degrees, I get no better than Nautical twilight, so the image lacks contrast and despite a fair bit of processing is still a bit noisy. Not a patch on my early April image . Just think if the SN had happened 2 months earlier....

And here is an animated GIF showing the supernova blinking against the earlier image. (Click on the pic for full size).