UMi Dwarf widefield. A nearby galaxy hiding in plain sight.

[symmetal]

I thought I'd have a go at this as something different. 🙂 This is after 5 hours of LRGB with an FLT98 and ASI6200. It hasn't been stretched all that much to avoid clipping the foreground stars too much. There are many small galaxies in the image though as the ASTAP annotation image shows. The small stretched image shows you where it is as you'll be hard pushed to locate it in the full size image. 😊 The brightest star in the image is HIP 74605, magnitude 5.15

It wasn't discovered until 1955 and is a spheroidal satellite galaxy of the Milky Way containing little to no star formation. It's longest dimension is about half a degree.

Alan

Edited April 9, 2022 by symmetal

[Mr Spock]

It's there once you know where to look but, not obvious at all. A tough one. Nice to see something different though.

[juno16]

I agree with Michael. Hard to spot, but if you know where to look (thanks for the annotation), there it is!

I definitely appreciate imaging something different and a tough catch like this target. Very nicely done Alan!

Your stars are beautiful too!

 

Jim

[symmetal]

Thanks @Mr Spock, @juno16 and others. On a single sub it's impossible to spot, and after stacking 20 L subs for checking I really had to convince myself that something was actually there.

I processed it gently in Startools using 'FilmDev' as there is nothing for 'AutoDev' to work on and AutoDev tends to give distinct halos on bright stars. No 'sharpening' or noise reduction performed, just star highlight control in the 'Color' module to reduce any residual coloured halos. I resampled it to 66% size in photoshop using bilinear interpolation to reduce the background noise and not alter the star overall shapes which bicubic can do. This also reduced the effect of coma, visible on the right hand side. Full size sensors will easily show any defects. 🙂 It's also a png image instead of jpg which helps too.

There are quite a few tiny galaxies visible which aren't shown in the PGC annotation.

Alan

Edited April 10, 2022 by symmetal

[glafnazur]

That is different, great image thanks for sharing 👍

[wimvb]

Nice! Now that you've got the UMi dwarf under your belt, you should try the Draco dwarf (ugc 10822) and the two UMa dwarfs. 😁

[symmetal]

8 minutes ago, wimvb said:

Nice! Now that you've got the UMi dwarf under your belt, you should try the Draco dwarf (ugc 10822) and the two UMa dwarfs. 😁

Thanks. 😊

The other ones you mention look to be more visually interesting and have plenty of stars making them more visible and galaxy like, so I'll give them a go. I was surprised how few stars seem to be in the UMi Dwarf along with no central concentration. Maybe there are fainter stars which will need more integration to reveal the typical Dwarf Spheroidal appearance, or there's dust in the way. I've done the Regulus Dwarf which I'll post shortly. 🙂

Alan

[wimvb]

11 minutes ago, symmetal said:

The other ones you mention look to be more visually interesting and have plenty of stars making them more visible and galaxy like

The UMa I dwarf was discovered in 2005, and is one of the faintest dwarf galaxies ever (UMa II is fainter).

https://www.astrobin.com/0gvm5z/

Draco dwarf is much brighter in comparison.

https://www.astrobin.com/397657/?q="PGC 60095"

[symmetal]

21 minutes ago, wimvb said:

The UMa I dwarf was discovered in 2005, and is one of the faintest dwarf galaxies ever (UMa II is fainter).

https://www.astrobin.com/0gvm5z/

Draco dwarf is much brighter in comparison.

https://www.astrobin.com/397657/?q="PGC 60095"

Oops. The images I saw were likely Hubble ones. The UMa ones are dim versions of the UMi Dwarf.😁 Still, worth a challenge rather than the usual objects. 🙂

Alan

[wimvb]

1 hour ago, symmetal said:

Still, worth a challenge rather than the usual objects. 🙂

Couldn't agree more. Unfortunately, astro darkness is drawing to an end here, and the moon is getting brighter every day. Astro season is all but over until mid-August. Otherwise, I would image the Draco dwarf.

I did image UMa 1 earlier this month, and I'm still processing it. Compared to this galaxy, the Draco dwarf seems like a light house.

 

[wimvb]

@symmetal, as promised: my version of faint 😁: UMa I dSph

 

[symmetal]

51 minutes ago, wimvb said:

as promised: my version of faint 😁: UMa I dSph

There should be an SGL challenge for most unexceptional galaxies. 😁

Alan