Stephan’s Quintet is to the left, consisting of 4 related galaxies and NGC 7320 which is a foreground galaxy. Their brightness’s range from +14.6 to +15.7. NGC 7318B is colliding with gas in the group, producing a huge shock wave bigger than the Milky Way, spreading through the medium between the galaxies, heating the gas to millions of degrees, emitting X-rays. A sixth galaxy, NGC 7320C appears to be connected by a tidal tail (just visible) to NGC 7319.
NGC 7331 or Caldwell 30 (to the right) is similar in size and structure to the Milky Way, 40M light years away. A discovery by William Herschel in 1784. It is the main body in the NGC 7331 Group, which contains unbarred spirals NGC 7335 and 7336, the barred spiral galaxy NGC 7337 and the elliptical galaxy NGC 7340. These other galaxies are all much further away (~300M ly), so not related to NGC 7331.
Looks ordinary but lots of interest in there if you dig a bit deeper – obviously not all associated with the cluster but just in the fov. Includes a fair number of galaxies, spectroscopic binaries, X ray sources, galaxy groups, radio sources, ir sources, stars with high proper motions. The cluster itself contains about 258 stars, mostly low mass in the main sequence or red giant stage. About 1300 ly away and just on the edge of naked eye visibility at mag. 5.7.
NGC 752 / C28
Open Cluster Andromeda Mag.5.7 Size 75′ 2021-11-01
Another go a this for the ASE Caldwell Project. A really tricky one this. Hidden in the dust from our own galaxy, this would actually be naked eye brightness if not obscured. From two sets of data but still challenging.
Added more data to this one but still very tricky. More horrible gradients to deal with. The IDAS P2 LP filter is no longer doing it’s job with the change in LP sources round here. Have now bought the IDAS D3 to see if that is any better as it deals more with LED lighting.
Bringing out the all the dusty, dark material leaves me with a horrible background.
Iris Nebula NGC 7023 / C4
2020-09-19 Mag. 6.8
250mm f4.8 Newtonian, MPCC
QHY168C @15°C 2/20 gain/offset IDAS P2
28x180s 10/50 darks, flats, bias
The Iris Nebula is a bright reflection nebula in the constellation Cepheus. The designation NGC 7023 refers to the open cluster within the larger reflection nebula designated LBN 487. The nebula, which shines at magnitude +6.8, is illuminated by a magnitude +7.4 star designated SAO 19158. Wikipedia
Sh2-155 is a diffuse nebula in the constellation Cepheus, within a larger nebula complex containing emission, reflection, and dark nebulosity. It is widely known as the Cave Nebula. Sh2 designation because it’s part of the Sharpless Catalog (1959) of 312 HII regions. About 2400 light years from Earth and a stellar nursery.
Narrowband filters really do cut through the murky, light polluted skies of Edinburgh so well. Obviously false colour, has to be for narrowband, but can’t decide which is the best so two different tone mappings: SII Ha OIII -> RGB and Ha OIII SII
Been meaning to do this one for ages. Not easy because the background gas and dust can be easily lost in the light pollution and noise.
“The Iris Nebula, also known as NGC 7023 and Caldwell 4, is a bright reflection nebula and Caldwell object in the constellation Cepheus. NGC 7023 is actually the cluster within the nebula, LBN 487, and the nebula is lit by a magnitude +6.8 star, SAO 19158.” Wikipedia
“IC 5146 (also Caldwell 19, Sh 2-125, and the Cocoon Nebula) is a reflection/emission nebula and Caldwell object in the constellation Cygnus. The NGC description refers to IC 5146 as a cluster of 9.5 mag stars involved in a bright and dark nebula.” Wikipedia
Processed 3 different ways – give different results, not sure which I like best. Still too noisy – need many more exposures. Interesting edge-on spiral galaxy in Coma Berenices, surprisingly large (14.9′ x 2′) but faint (9.60 but surface brightness 13.3). It is actually intrinsically more luminous than the Andromeda Galaxy. First seen by William Herschel in 1785. Also visible lower right is NGC 4562.
NGC 4565, Caldwell 38 Spindle Galaxy
203mm RC8 f8
Atik 460Ex @-20C Badder RGB filters IDAS P2 LP filter
Added 18 frames of Ha. Much more detail and less noise.
NGC 7635 Bubble nebula (C11) Mag. 10, Size 15’x8′ H II region emission nebula Cassiopeia
2018-09-23 21:15-23:07 UT Bright moonlight
200mm f5 Newtonian, MPCC IDAS P2 LPR filter Guided
Atik 460EX, Baader 7nm Ha filter
18 x 300s darks, flats
Nebulosity 4, Photoshop
I did take some RGB colour but as you can see below there is a huge dust mark in it. Normally not a problem as flats will remove it. But when I went to create flats, the dust had disappeared so very difficult to remove. Unless it’s not dust but an out of focus reflection of the bright star? If it is I’ve never seen anything like it in my images before.