Jason Nishiyama @evilscientistca@octodon.social

There are quite a few galaxies in that M59-M60 mosaic. Here are the ones I found and where they are in the picture. Known distances as well:
1 PGC 1394064
2 M 60 - 54.4 Mly
3 NGC 4647 - 57.3 Mly
4 PGC 1397198
5 NGC 4687 - 110.2 Mly
6 NGC 4638 -50.7 Mly
7 IC 3684 - 49.6 Mly
8 M 59 - 52.2 Mly
9 IC 3672/IC 809 - 51.4 Mly
10 PGC 42634
11 IC 3665 - 52.5 Mly
12 IC 3670 - 22.8 Mly
13 NGC 4607 - 57.6 Mly

M60 and M59 are quite close together in the sky as well, being less than a degree apart. Here are the images of M59 and M60 as a mosaic.

More from a week ago Wednesday, M60 (the elliptical galaxy near centre). 20cm f3.9 Newtonian, 8 min L, 3 min each R,G,B. A member of the Virgo galaxy cluster, M60 is about 54Mly from Earth. The spiral galaxy next to M60 is NGC 4647 at 57 Mly distance. #astrophoto

Continuing from last week's imaging: Elliptical galaxy M59, another member of the Virgo group of galaxies, this one located about 52 Mly from Earth. 20cm f3.9 telescope. 8 minutes L, 3 minutes each RGB. #astrophoto

Boeing taking OS lessons from Microsoft? http://evl.link/j7

From Wednesday last week: Spiral galaxy M58. 20cm f3.9 Newtonian, 7 min L, 3 min each RGB. Located in Virgo, M58 is part of the Virgo cluster of galaxies. It's about 60 Mly away from the Earth.

‪So the morning when I’m not going to be working from home...‬

From last Wednesday, elliptical galaxy M49. 20cm f3.9 Newtonian telescope. 9 min L, 3 min each RGB. Located in Virgo and part of the Virgo cluster of galaxies, M49 is about 52 Mly away from us. #astrophoto

From last Wednesday, Open cluster M48 - 20cm f3.9 Newtonian telescope, 8 min L, 5 min each RGB. It is located about 2500 ly from Earth in the constellation of Hydra. #astrophoto

Continuing on from Wednesday's observing: Open cluster M47. Located in the constellation Puppis, it is about 1600 ly from us. #astrophoto

From Wednesday: The open cluster M46 with planetary nebula NGC 2438. 20cm f3.9 Newtonian telescope. 6min L, 3 min each RGB. NGC 2438 is not part of the cluster, lying about 1500 ly closer to us. #astrophoto

The technique seems to work well. I'll have to use it more often as it saves considerable time (1.25 min vs 5 min, for example).

I then set the imager to bin at 2x2 and then proceeded to take 5 images each for RGB at 15 seconds of integration. The binning makes 15 seconds the equivalent of 1 minute. So a total of 1 min 15 sec per colour channel.

Registration went smoothly and the results are here for comparison. The first image is just the binned RGB images scaled to full resolution. The second has the L images included as luminance.

Fortunately the software I use, IRAF and some code of my own fiendish devising, is up to the task it would seem. I used some of my scope time last night to try this out on the nebula M42.

So I took a couple of images of M42 at full resolution through the luminance (L) filter (basically a UV/IR cut-off filter) at 60 seconds each for 2 minutes of integration.

I've not done this before because the software I used when I started didn't have the ability to properly register images of different resolutions. It's a complicated thing registration, which is lining up all the stars so they're in the same place.

To register plates of different scales (resolution) the registration program not only has to shift and rotate the image, but work out a scaling factor to apply.

However it is possible to bin pixels together. That is take the pixels and add them together in a 2x2 box and make that a single pixel. The advantage of this is you get the same brightness information in 1/4 the time.

The disadvantage is you get an image of 1/2 the resolution. For LRGB photography this isn't an issue since the detail information comes from the L image. So, hypothetically one can bin the RGB filters to save time.

So last night I tried a new (to me) astrophoto technique. Normally I take images for pretty picture astronomy through 4 filters, RGB for colour and L for brightness information. (images at the end of the thread)

This is usually done at full camera resolution for all filters. You save some time at the telescope because you don't need as much integration (exposure) time for the RGB filters.

Whoops! Made a mistake. Wrong telescope - this was taken with an 80mm f5 refracting telescope (it has a wider field of view)...