The Sculptor Group of Galaxies
17 Oct 2017
Last night I observed the Sculptor Group of Galaxies, the nearest to our own Local Group of Galaxies. It provides a lovely observing experience as it certainly does contain some beautifully bright and shapely galaxies (along with a number of dim to exceedingly-dim and less-shapely members). However, whenever I look at galaxies, beyond the beauty I am seeing when I centre an entire galaxy in the eyepiece, my brain always strives – and fails – to get the smallest glimmer of understanding of: How big is big? How far is far? How long is long? As all stargazers know, one can observe an object but you don’t really come to appreciate it until you grasp the immensity of what it is that the eye beholds, even though our brains are actually completely hopeless at understanding cosmic ‘big’, ‘long’ and ‘far’. But it was a nice thing to mull over as I made a telescopic trip to the next-door congregation of galaxies in our own little corner of the universe.
Observations
16″ f/5 Dobs at magnifications of 150x, 228x, and 333x
NGC 253 Galaxy
RA 00 37 33.5 Dec -25 17 28 Mag 7.2 Size 29.0′ x 6.8′ SB 12.8 PA 52°
Discovered by Caroline Herschel on September 23, 1783 with “…an excellent small Newtonian sweeper….” this is surely one of the most beautiful galaxies in the eyepiece, and no matter how many times I look at it, I am struck by its splendour and grandeur. In fact, the only word that does it justice is majestic. The galaxy is only 12° from edge-on, an absolutely stunning sight in itself, and with its incredible mottling and dust structure, dark lanes with swirls and rifts, dark knots, and brighter patches, it actually defies description with all its detail. It reminds me of Turner’s magnificent paintings with his distinctive turbulence of blazingly bright light, and terrifyingly deep shadows of smoke, soot, and dust. Indeed, it is one of those objects that is very difficult to drag yourself away from because there is just so much to see. I tried to see if I could spot the globular clusters that roam its nether regions, but alas, way out reach of my equipment and my eyes. However, talking of globulars, it is impossible to look at NGC 253 and not immediately go to the globular cluster that shares its limelight – NGC 288. Stephen O’Meara put it thus, “Few sights in the sky are as rewarding as seeing this dramatic pairing of deep-sky splendors.”
NGC 288 Globular Cluster
RA 00 52 45.5 Dec -26 34 51 Mag 8.1 Size 13.0′
This globular is a delight in the telescope, even after the splendour of its neighbour. It has a very loose, irregularly round appearance and albeit having a low surface brightness, it stands out beautifully against the background sprinkled with mixed stars. Handfuls of stars are resolved across the globular, all set against the loveliest soft haziness of unresolved starlight. Its outliers seem to drift off in a haphazard fashion into the background. Its small and slightly brighter core region has a very slightly squarish look to it and contains a beautiful little bundle of resolved stars. Unlike most globulars, I can’t distinguish the usual strings and curves and whorls stars one sees; the only definite string I can see runs through the western side of the halo in a NNE-SSW direction.
As if anyone needs more eye candy among all this stellar splendour, I took a squizz at R Sculptoris, an absolutely gorgeous carbon star, which lies 9½° SE of NGC 288…
R Sculptoris
RA 01 26 58.09 Dec −32 32 43 Mag 5.72
To me carbon stars are the most beautiful stars. I’ll never tire of looking at them. In these beautifully dark Kalahari skies some carbon stars smoulder like red-hot embers, others glitter like stellar rubies, and some are the blood-red of J.R. Hind’s famous blood-drop – R Leporis. R Sculptoris is in the red-hot ember class, smouldering against the sky; bright, striking and beautifully red. Absolutely gorgeous. (A peculiarity of observing carbon stars has to do with the Purkinje Effect – the eye’s perception of red-hued objects in low light – so the longer I stared at beautiful R Sculptoris, the redder and brighter it became.) What a visual delight a carbon star is!
Then it was back to the Sculptor Group of Galaxies:
NGC 55 Galaxy
RA 00 15 05.9 Dec -39 13 01 Mag 7.9 Size 32.4′ x 5.6′ SB 13.4 PA 108
NGC 55’s nickname, String of Pearls, is very fitting – it’s a striking almost edge-on spiral with its delicate lacework of dark dust lanes and beautiful brighter pearly-looking patches in its central region, which really come to life with averted vision. It is a huge, gloriously bright, remarkably elongated spindle with very interesting ends: the western end is bright and elongated, and easily delineated where it fades into the background, whereas the eastern end is a lot dimmer and seems to simply dissolve into the background. Beautiful mottling runs the length of the galaxy, although it requires averted vision to follow it into the eastern side before it fades. The central region is beautifully bright and offset WNW of centre. In his inimitable Celestial Handbook, Burnham mentions that with larger telescopes “…Near the centre of the main mass, a little to the east of the nucleur region, a very prominent and sharp-edged dust cloud may be seen…” Without having read about this, I wouldn’t otherwise have seen it, but with averted vision I was able to bring this little dark blot into sight, a shadowy smudge of darkness.
NGC 300 Galaxy
RA 01 54 53.3 Dec -37 41 02 Mag 8.1 Size 19’x12.9′ SB 14.0 PA 120
This galaxy reminds me of the Small Magellanic Cloud seen with the naked eye! It has the same delicate, gossamer mistiness and soft hazy edges that seem to melt into the background sky. It is a pretty faint, fairly large, very diffuse oval elongated WNW-ESE, with soft hazy edges. It brightens slowly and gradually to the centre. No sign of structure, although with averted vision the centre has a very vaguely mottly look. Not enough to be called mottled, but not smooth. There are a number of Milky Way stars superimposed on the face of the galaxy.
NGC 247 Galaxy
RA 00 47 07.0 Dec -20 44 36 Mag 9.1 Size 19.2’x5.5′ SB 14.0 PA 172
This is a lovely galaxy – a long, large, fairly bright galaxy elongated N-S. The central area has a vaguely mottled look and brightens gradually to a bright and extended core. The northern portion of the galaxy broad and diffuse and rounded at its end; while the southern portion appears brighter and has definite pointy end. However, there is a 9th mag star superimposed on its southern end which may give it the illusion of pointy. A number of other faint Milky Way stars are superimposed on its halo.
NGC 625 Galaxy
RA 01 35 05.0 Dec -41 26 11 Mag 11.2 Size 5.8’x1.9′ SB 13.6 PA 92
The starburst galaxy is a lovely sight in the telescope because it has a rather unusual appearance – appearing as a bright-ish, large-ish, extended E-W oval that is curiously irregular in both shape and brightness. It is surrounded by a thin fainter halo. Averted vision shows up the irregularity of the central region; the western end seems more blunt than the eastern end, which seems sharper in comparison, and although the glow is by no means mottled or knotty, it has an odd uneven brightness, not quite lumpy looking, but definitely not smooth and even. Very unusual.
NGC 7793 Galaxy
RA 23 57 49.8 Dec -32 35 26 Mag 9.1 Size 9.3’x6.3′ SB 13.4 PA 98
Another lovely galaxy! It is a very large, relatively bright oval elongated WSW-ENE. It brightens to a smallish core that has a vaguely mottled appearance and itself brightens to a small and indistinct brightness in the centre. With averted vision the halo shows texture; not exactly structure, but very ambiguous and indistinct hints of something structural. A Few faint stars on the northern edge. I can see a few faint Milky Way stars superimposed on its northern edge.
NGC 59 Galaxy
RA 00 15 25.5 Dec -21 26 43 Mag 12.4 Size 2.6’x1.3′ SB 13.6 PA 127
This little galaxy appears as faint, small, oval, elongated WNW-ESE, and with a small and brightish little core.
IC 1574 Galaxy
RA 00 43 03.8 Dec -22 14 47 Mag 13.7 Size 2.0’x0.7′ SB 13.9 PA 175
Try as I did, I couldn’t pick this chap up. Not even averted vision gave me any “refined capacity for comprehension”. And indeed this was the end of the Sculptor Group of Galaxies for my equipment and eyes.
Copyright © Susan Young 2017