Cassiopeia Galaxies

[Mike JW]

We would not normally associate galaxies with Cassiopeia but there are three very interesting galaxies to be viewed.

NGC 147 and NGC 185. (Also NGC 278)

These two galaxies are a gravitationally stable binary pair. Both are dwarf spheroidal galaxies (E5 and E3 respectively) lying around the 2.6 million lyr mark. They are satellite galaxies of M31, along with its more famous satellites M110 and M32. They are about 35,000 lyrs apart. NGC 147 has a mainly old star composition. In contrast NGC 185 has a very luminous nucleus (Sy2), with star formation.

NGC 278 is a Ring Galaxy so I shall post it in the ring galaxy thread)

Mike

[rwilkey]

You are so right!  I love Cassiopeia  and what it offers.  Well done!

[Davesellars]

Nice captures, Mike!   NGC 147 is quite diffuse without a bright core which can make it difficult visually.  I see I haven't logged this one as observed yet.  NGC 185 has come out really well with a touch of structure appearing and those two small dark areas.  Well done!

[Mike JW]

I was surprised by the dark areas (try not to look at decent images before viewing a target) in NGC 185. Apparently, these dust areas were first picked up in 1951 when it was thought that the galaxy was entirely old stars (Population 2 stars). However later studies have revealed some luminous blue stars in clusters.

Here is a zoomed in shot showing these dust clouds.

This link shows a superb image of the area: APOD: 2021 November 4 - NGC 147 and NGC 185 (nasa.gov)

Mike

Edited October 19, 2022 by Mike JW
added image

[roelb]

I took a look in my past observations and found also those 2 galaxies.

NGC 147

Evo 8 @ F/5

Lodestar X2 mono

7 x 20 s

 

NGC 185 (and UGC 378)

Evo 8 @ F/5.3

ASI533MM

61 x 15 s

[Mike JW]

Hi Roel,

My fov was too small to pick up UGC 378, so no doubt I will re-visit the area. As always, your wider fov gives a better context.

Mike