M33 – Triangulum

M33 - Triangulum Galaxy

Below Andromeda is the smaller Triangulum Galaxy M33. This is 20 exposures of 100 seconds at 800 ISO through the Z61 so 360mm f/5 with calibration frames from other nights. It’s not great but better than my previous effort.



This is not very good although it’s much better than my previous attempt. Twenty lights of 30 seconds at ISO 1600 through the Z61 scope(360mm f/5.9) guided with PHD2. I have had decent results at ISO 1600 but I compared a single sub at 60 seconds ISO 800 and it showed less of the mottling I see in this one. If I try this again I’ll do a solid 30 minutes of 60 second subs at 800.

M33 – The Triangulum Galaxy

20-01-04 M33

This is a very sad sort of thing to be pleased with, but I am!  On the left is the Triangulum constellation with alpha Triangulum near the center bottom, in the right top corner is Mirach in Andromeda.  The faint puff of gray off to the right about 1/3 of the way from alpha Tri to Mirach is the Triangulum galaxy!

This was 7 shots at 30 seconds with the Canon T3i, 50mm lens at f/2.8, and ISO 800.  The shots were stacked with Deep Sky Stacker then adjusted with Rawtherapee.  I picked the best 7 of 9 shots to stack and used the recommended parameters, in Rawtherapee I just played with the various sliders.  Black point is set to 5176, Shadow Compression to 0, Lightness to -6, and Contrast to +61.  All of those had some effect but Black and Shadow Compression probably the most.

My plan had been to shoot for 60 seconds at f/3.5 ISO 800 which is a bit more light but there is too much sky glow in my back yard.  My best shot of Bode’s Galaxy and the Cigar Galaxy was 60 seconds f/4 ISO 400.

The thumbnails below are just reminding me what the DSS and Rawtherapee screens look like:

UPDATE: Below is a further overprocessed image from rawtherapee and the corresponding settings. I note that in the original image I could see a bit of M31 the andromeda Galay in the top right. If I could reliably frame the two galaxies in would be an interesting image. Also, the jumble near the center of the original is NGC752 – an open cluster.


19-12-04 astrometry M33

Conditions were perfect the other night for imaging the Triangulum Galaxy, M33 from my back yard.  I could see Polaris over my neighbours’ houses and the constellation was almost overhead.   I had my usual sh*t show setting up and the only thing i ended up with was the last of my setup shots: 20 seconds at f/5.6 ISO 1600 with my 18-55mm lens fully zoomed.  I shot a full session with the 50mm lens after that but the focus was out.  Anyway, Astrometry confirmed that I was pointed to the right part of the sky.  which is between Triangulum and Mirach in Andromeda. In the image above from astrometry I added the “M33” text to show where it should be.

19-12-04 green_4359

Looking real hard at the area the eye of faith says there’s a smudge but really nothing to be sure of. M33 is just a bit dimmer than M110 which shows up as a puff in shots taken with my 50mm lens 60 seconds f/3.5 ISO 800.  So I was more or less exposing the same but for only 1/3 of the time.

So, for next time: check that the battery is in the camera(!); make sure the headlamp works; remember to pre-focus the 50mm lens and tape it; check that all the screws are tight on the mount and tripod; and try for 60 seconds, f/3.5 ISO 800 with the 50mm lens.

UPDATE: processing the image a bit more subtly with something called Rawtherapee I’m morally sure there’s a faint puff at the right spot so next clear night should do it. I can still see it in the cropped shot below but mostly because of the star patterns around it.
19-12-06 IMG_4359_rawtherapee