M81 & Holmberg IX

[Taman]

One of my favourites, Bode's Galaxy in Ursa Major. Dwarf galaxy Holmberg IX is also faintly visible on the left of the image.

My first proper RGB image taken with a mono camera over 2 nights. To save time I didn't take luminance, instead using Pixelmath to generate a synthetic luminance from the RGB data. I researched this on the forums and found arguments both for and against, but it really helped and resulted in very low levels of noise! I wonder if adding real luminance has this nice side effect? 

I've identified a couple of Quasars so far and faint stars and "fuzzies" below magnitude 20. Not bad for less than 7 hours exposure time.

Hope to add more to this as a long term project, perhaps even some luminance data, anyone have any thoughts on this?

CS, Tony.

134 x 180s RGB, total exposure time 6h 42m.

C11 at f6.3, ASI294MM Pro

[Xilman]

Thoughts you want?  How about processing for faint stellar objects, possibly in grey-scale?  You should then pick up dozens of globular clusters.  I can tell you now that you already have several.

See https://britastro.org/observations/observation.php?id=20190311_020000_9a2c47fcf9f3ee97 for more information. I can provide a catalogue of GC positions and magnitudes on request.

 

[Taman]

7 hours ago, Xilman said:

Thoughts you want?  How about processing for faint stellar objects, possibly in grey-scale?  You should then pick up dozens of globular clusters.  I can tell you now that you already have several.

See https://britastro.org/observations/observation.php?id=20190311_020000_9a2c47fcf9f3ee97 for more information. I can provide a catalogue of GC positions and magnitudes on request.

 

Thanks for that, nice idea! Yes please to the catalogue. I'll take a closer look at my image and process a version for the background, perhaps with some deconvolution. Interesting that the study involved taking several hundred short 30s exposures of M81, presumably to reduce the blurring effects from seeing. 

[Paul M]

That's very nicely done.

It's maybe my imagination but M81 seems to ha little out of fashion in recent times. My own experience of imaging M81 has not been positive. I've been very dissapointed with my efforts and I suspect my primary failing has been in processing. I've turned quite promising subs into a stack of garbage! So it's always nice to see it done well

P.S. Don't listen to @Xilman, your imaging life will never be the same again! 🤣 

[Xilman]

41 minutes ago, Taman said:

Interesting that the study involved taking several hundred short 30s exposures of M81, presumably to reduce the blurring effects from seeing. 

Actually because the autoguiding has never worked very well. This approach allowed me to dump the trailed subs.

[Taman]

38 minutes ago, Paul M said:

That's very nicely done.

It's maybe my imagination but M81 seems to ha little out of fashion in recent times. My own experience of imaging M81 has not been positive. I've been very dissapointed with my efforts and I suspect my primary failing has been in processing. I've turned quite promising subs into a stack of garbage! So it's always nice to see it done well

P.S. Don't listen to @Xilman, your imaging life will never be the same again! 🤣 

Thanks for the nice comments Paul! I also had problems with this image and it took me several attempts to get the colour calibration right (lack of blue). Don't throw away your data just yet!

I'm not sure how deep I want to go down the rabbit hole that @Xilman suggested, but it's interesting to see what my 21 year old SCT is capable of. I also like doing pretty images for Astrobin, so probably not too deep! 😁

Cs, Tony.

[Xilman]

44 minutes ago, Paul M said:

P.S. Don't listen to @Xilman, your imaging life will never be the same again! 

What on earth do you mean? 🤨

[Paul M]

1 minute ago, Taman said:

I'm not sure how deep I want to go down the rabbit hole that @Xilman suggested, but it's interesting to see what my 21 year old SCT is capable of. I also like doing pretty images for Astrobin, so probably not too deep! 😁

I've engaged in a few projects suggested by Paul (Xilman) and they have all been DEEP! But that suits my imaging and processing style. Not good a extended objects but I can eek out tiny, exotic subjects.

[Xilman]

1 minute ago, Paul M said:

I've engaged in a few projects suggested by Paul (Xilman) and they have all been DEEP! But that suits my imaging and processing style. Not good a extended objects but I can eek out tiny, exotic subjects.

Exotic is good, IMAO.  I mean, who really wants to take the 13,572nd image of M31 or M42?  Show a bit of initiative and individuality, please!

[Paul M]

2 minutes ago, Xilman said:

What on earth do you mean? 🤨

You haven't forgot the Cosmic Horseshoe already, surely? 😉

And what was that, I spent hours and hours and hours digging deep for?  Gǃkúnǁʼhòmdímà . I got it though, cost me my marriage, my job and my sanity 🤣

[Xilman]

We do these things not because they are easy but because they are hard.  JFK.

Easy is boring, IMAO.

Things what don't move are nowhere near as hard as things which do.  The CH, HVGC-1, and the like can be imaged for as many hours as it takes, on as many nights as it takes.  I've seen folk here bosting about collecting photons from a single object for tens of hours. That effort will easily pick up sub-20th magnitude objects with a 15cm aperture telescope. Indeed, I've seen on SGL a pretty picture of M31 taken with a 75mm refractor which showed stars and GCs in the galaxy down to somewhere about mag 18.

Much harder are objects which move significantly from night to night. Four hours on a 20cm will let you locate TNOs, asteroids, or satellites in the outer solar system down to below 20th magnitude or so, as long as you stack subs on the predicted motion of the object.