Andrew's Astronomy Blog

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 .

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.