A clear evening, the moon approaching third quarter and a long weekend courtesy of the Easter bank holiday; what to do…
No debate really; add some data to my Whale and Hockey Stick picture. Originally started at the Kelling Heath star party, I’ve subsequently added another 2 hour set and this was the third, taking me up to 6 hours in total.
Replacing the Belkin USB hub with a Startech has stopped the lockups of the guider. I’ve still got a dry solder joint to track down in the power supply somewhere. I have my suspicions but I’m aiming to replace the cigarette lighter sockets with something a lot more substantial in the near future.
Stacked in Maxim DL
Processed with Pixinsight
Despite a first quarter moon in the sky I couldn’t pass up the chance of a clear night so last Tuesday I set up in the back garden. Things didn’t go exactly to plan and a Netbook reboot at 3am for Windows updates cost me a few hours but I did get 2 hours 20 in 10 minute subframes of a galaxy triplet in Coma before then. The central galaxy is NGC 4216.
As this is part of the Coma cluster there are a lot of other galaxies in the field as well.
Processed in Maxim DL and Pixinsight.
In between the high cirrus clouds that were prevalent over the Kelling star party last weekend I got a couple of hours worth of exposures of these galaxies in Canes Venatici. (ngc 4631, 4627, 4656 & 4657). Because they’re both fairly large at 16 arc minutes they make a nice combination for the Baby-Q and QHY9. This combination produces a pixel scale of 2.475″/pixel which is a little coarse for imaging the finer detail in galaxies but with the UK’s pretty average seeing conditions probably isn’t too under-sampled most of the time.
The Hockey stick has two NGC numbers; 4656 which is the core and 4657 which is the bright knot at the distorted eastern end. This distortion is due to interaction with the Whale and both galaxies are at a distance of 30 million light years.
Acquiring some more data will help bring up more faint detail in the galaxies. I’m very pleased with the colour rendition by this telescope / camera combination in both this image and the previous Leo Triplet image.
Back at the beginning of March I took a couple of hours worth of 10 minute exposures of the Leo Triplet (M65, M66 & NGC3628). Having stacked them in Maxim as I normally do I found that the intensities were very wrong when opening the fits file in Pixinsight for further processing. I haven’t got to the bottom of this yet but I’ve re-calibrated and stacked using Pixinsight instead which has worked around the problem.
Looking back through my images I first took pictures of this group at Kelling back in spring 2010 .
A conversation at the club about the problems caused by bright stars in photographs of faint objects led to a couple of sessions imaging IC443, the Jellyfish, in Gemini. Eta Gemini is a magnitude 3.3 star alongside the supernova remnant. Photo opportunities for this object this year are closing fast as it’s culminating as it gets dark. I’ve managed two sessions during this New Moon period for a total of 3hrs 20 minutes in my usual 10 minute subs.
Early attempts at processing were rather heavy handed with noise reduction so I’ve toned that down in this version and applied most of it when the image was still in it’s linear form. This has left more of the finer nebula structure intact.
A lot of the images of this nebula on the Internet are done with narrow band filters which suppress Eta Gemini but when using a One Shot Colour camera the star rather dominates. I’ve toned it down using the StarhaloReducer script in Pixinsight but I could probably be rather more aggressive with this.
Somewhat fortuitously, after my last post of M81 & M82 a type 1a supernova has erupted in M82. After large amounts of rain, the clouds parted last night and I was able to take some additional pictures showing the event. All of the stars in this image, except for the additional one within the outline of the galaxy are local stars in our own Milky Way. The supernova is 12 million light years away which gives some idea of the power of this explosion.
I’ve had less practice processing images of galaxies so this picture has been on my hard disk whilst I tried different processes to see what worked and what didn’t. The increase in focal length from 330 to 450mm switching from the Zenithstar 70 has made a big improvement in image scale but, with the exception of M31 & M33, groups of galaxies work better to fill the frame.
I’ve imaged this pair before but this is the first time I’ve managed to capture the Ha streamers from M82. This is 3 hours of data in 10 minute sub-frames.
This is a test image checking operation of my new imaging setup based upon the Takahashi FSQ85-ED ‘Baby-Q’. After running several V curves in FocusMax I took 12x 5 minute exposures of M45. This is a good test of the optics as the stars are very bright and are a useful check for spurious reflections.
I’ve built a new flat panel using a larger EL panel and some translucent polycarbonate. The panel is still a little bright and I’ll need add a little more attenuation to enable me to use somewhat longer exposures to eliminate shutter artifacts.
I’ve finally got around to combining the remaining data into a mosaic of this area. Using a different technique to merge the images in Pixinsight I’ve removed the visible join that was due to a light pollution gradient in the original.
Sh2-155 is a region of Ha emission overlaid with dust in our galaxy, some of it thick enough to block the more distant stars completely and appear black.
This is a total of 10 hours 20 minutes of 10 minute subframes.
I’ve been meaning to capture a new version of this nebula as the previous one, done on the Astrotrac exhibited quite pronounced trailing. This will be one of my final images done with the WO Zenithstar 70 as I’ve purchased an ex-demo Takahashi Baby-Q (FSQ85-ED). I’ve enjoyed working with the Zenithstar and I’ve learnt a lot in the years of using it but the time has come to upgrade to something with rather better colour correction and a flatter field.
Fifteen 10 minute subframes using my QHY9C.