ngc 147 with globular clusters

[wimvb]

After that very weak Andromeda dwarf galaxy And XXX, it is now time to tackle its larger and vastly brighter sibling, ngc 147. This is also a spheroidal dwarf galaxy, but with an absolute magniture of -15 (rather than -8 for And XXX). Its apparent magnitude is 9.5

Ngc 147, or Caldwell 17, is situated in the constellation Cassiopeia, at an approximate distance of 2.5 Mly. It was discovered by John Herschel in 1829.

Ngc 147 is host to several globular clusters, some of which are indicated in the annotated Luminance image.

Technical data:

Gear: SkyWatcher 190MN on SW AZ-EQ6, ZWO ASI294MM with Optolong LRGB filters

Total integration time approximately 6 hrs, of which L 2.5 hrs

Processed in PixInsight

Edited November 20, 2022 by wimvb

[symmetal]

That's an impressive image Wim. Not sure if there's a hint of the debris streams visible. 🤔 I found this article detailing the globular clusters and evolution of NGC147.

If this poor weather here clears I can have a try with my RASA 11 and LRGB filters to see if any more features can be seen.

Alan

[wimvb]

4 hours ago, symmetal said:

That's an impressive image Wim. Not sure if there's a hint of the debris streams visible. 🤔 I found this article detailing the globular clusters and evolution of NGC147.

If this poor weather here clears I can have a try with my RASA 11 and LRGB filters to see if any more features can be seen.

Alan

Thanks, Alan.

If I use PixInsight Multiscale Median Transformation to push the diffuse, large scale field of the galaxy really hard, it gets kind of a rectangular shape, which could coincide with the onset of the tidal stream. But this is very uncertain, because weak halos of the star field interfere with the halo from the galaxy. But if the weather clears up before the galaxy is too low in the sky, I plan to add more data to this image. With the data I have, I can also just about see some ifn. Probably.

The big problem for me is that the weather just isn't good enough in autumn, to capture very faint signal. The high moisture content of the air results in low transparency, and on several occassions I've had to abort my imaging sessions due to ground fog, despite my observatory being situated some 7 meters or so above the surroundings to the south.

[beka]

8 hours ago, wimvb said:

After that very weak Andromeda dwarf galaxy And XXX, it is now time to tackle its larger and vastly brighter sibling, ngc 147. This is also a spheroidal dwarf galaxy, but with an absolute magniture of -15 (rather than -8 for And XXX). Its apparent magnitude is 9.5

Ngc 147, or Caldwell 17, is situated in the constellation Cassiopeia, at an approximate distance of 2.5 Mly. It was discovered by John Herschel in 1829.

Ngc 147 is host to several globular clusters, some of which are indicated in the annotated Luminance image.

Technical data:

Gear: SkyWatcher 190MN on SW AZ-EQ6, ZWO ASI294MM with Optolong LRGB filters

Total integration time approximately 6 hrs, of which L 2.5 hrs

Processed in PixInsight

Very nice and interesting. I checked the specs of your scope and it seems to be corrected to APS-C size with no additional accessories - and at f5.3. Just wondering why this kind of scope is not more popular for astrophotography. I searched SGL for your image of And XXX but could not find it. I would appreciate it if you could link it. 

Best

[wimvb]

2 hours ago, beka said:

Very nice and interesting. I checked the specs of your scope and it seems to be corrected to APS-C size with no additional accessories - and at f5.3. Just wondering why this kind of scope is not more popular for astrophotography. I searched SGL for your image of And XXX but could not find it. I would appreciate it if you could link it. 

Best

The title isn't the most obvious, probably. 🙂

As for the reason why this scope isn't more popular, people generally complain about its weight. But it actually weighs less than a refractor of smaller (156 - 180 mm) aperture. It certainly lightens ones wallet less.

An astrophotographer in Northern Sweden used a 190MN for one astroseason, but decided it was too heavy to carry in 1 m snow, which I can understand. This scope performs best in a permanent setup in an observatory. Much lika a 180 mm apochromatic refractor. 😁

Edited November 20, 2022 by wimvb

[wimvb]

11 hours ago, symmetal said:

That's an impressive image Wim. Not sure if there's a hint of the debris streams visible. 🤔 I found this article detailing the globular clusters and evolution of NGC147.

If this poor weather here clears I can have a try with my RASA 11 and LRGB filters to see if any more features can be seen.

Alan

This image shows that if you push the data hard enough, a box like structure starts to emerge. This is the starless boosted image and the same with the stars brought back in.

One could argue that some ifn is visible, but imo the star halos that remain after StarNet has done its thing (and enhanced by the boosting treatment) interfere too much to make that assumption.