Sculptor

A veritable mecca for galaxy hunters. The constellation of Sculptor was formed by Lacaille in 1752 from a bunch of inconspicuous stars lying between Cetus and Phoenix. There are few bright stars of note in the constellation, with most being no brighter than mag 4.5.

The constellation covers an area of some 475 sq deg and culminates at midnight on around the 27th of September. The region of Sculptor lies off the galactic plane and is hence strewn with extra-galactic nebulae. Some of the brighter galaxies such as NGC 253 are fine telescopic objects through any size telescope.

Apart from the stars that are in Sculptor, the only other thing in the constellation that is an object belonging to our Milky Way galaxy is the Globular cluster NGC 288.

NGC 253

One of the best galaxies for southern hemisphere observers. NGC 253 is a large, quite elongated spiral galaxy and one of the most prominent objects for small amateur telescopes. This lovely spiral galaxy was discovered by Caroline Herschel in 1783 during a systematic search for comets. John Herschel some 50 years later described the object from the Cape of Good Hope as “very bright and large, 24’ in length, a superb object”.

A description from the NGC/IC Database as follows;

"NGC 0253 = ESO 474-G29 = MCG -04-03-009 = UGCA 13 = Sculptor galaxy = PGC 02789

00 47 33.1 -25 17 17

V = 7.2; Size 27.5x6.8; SB = 12.7; PA = 52d"

"17.5" (8/29/92): very bright, very large, edge-on 6:1 SW-NE, 30'x5', possibly 35' length at 100x. Remarkable dust structure and mottling visible particularly on the SW extension and a dark lane runs along the north side. On the SW extension three faint HII knots are visible near an embedded star; just SW and a bit further NW of the star and a slightly brighter knot to the NE of a star near the core. The galaxy exhibits only a weak central concentration to a small elongated core slightly larger than the knots. Several stars are superimposed on the galaxy".

"13" (9/11/82): very bright, elongated 4:1 SW-NE, very mottled, dust lanes, dark patches, 30' diameter.

"8": very bright, very elongated, mottled, 25'-30' diameter.

by Steve Gottlieb"

NGC 55

Another outstanding southern galaxy, much elongated and irregular in shape. It has been classed both as a loose-structured spiral galaxy or a flattened irregular system somewhat like a giant version of the LMC. Telescopes above 26cm will begin to show the emission nebulae, dark patches and H-II regions.

THE SCULPTOR DWARF GALAXY (PGC 3589)

A very enigmatic type of dwarf galaxy, and member of the Local Group of galaxies. First discovered on photographic plates at Harvard observatory by Harlow Shapley in 1937. It is a dwarf spheroidal galaxy and was the first of its type discovered. It is a very difficult object to observe for amateur astronomers. The best chance is to use a wide field telescope with a low power eyepiece of around 30x mag or less.

KLEMOLA 44

Situated near the mag 4.0 star Delta Sculptoris is the galaxy cluster Abell 4038 (Klemola 44). At some 400million light years away, it is a cluster that is rich in early type galaxies, and does not contain many spirals of note. Brightest galaxies in the cluster are at about mag 13.0. The central object is IC 5358.

Klemola 44 is at R.A. 23 47 45 DEC-28 08 25.

THE CARTWHEEL GALAXY

The Cartwheel Galaxy (ESO 350-40) is a lenticular galaxy about 500 million light-years away in the constellation Sculptor. It is about 150,000 light-years across. The galaxy was once a normal galaxy like the Milky Way before it underwent a head-on collision with a nearby galaxy. When the nearby galaxy passed through the Cartwheel Galaxy, the force of the collision caused a powerful shock wave through the galaxy, like a rock being tossed into a sand bed. Moving at high speed, the shock wave swept up gas and dust, creating a starburst around the galaxy's center portion that were unscathed. This explains the bluish ring around the center, brighter portion.The Cartwheel can be difficult to observe.

In large amateur scopes the actual ring shape can be glimpsed along with the two faint companion galaxies. A challenging object, requiring good seeing conditions and a dark sky site to observe from to ensure optium chances of observation.The Cartwheel is at R.A. 00 37 40.2 DEC-33 42 59.

NGC 288

This globular cluster was discovered by William Herschel on October 27, 1785 and catalogued by him as H VI.20. The cluster attracted attention of astronomers in the late 1980s when it was compared with the otherwise similar globular cluster NGC 362 on about the same right ascension (but much more southern), and found that NGC 288 must be about 3 billion years older. This result was found because of differences in the colour-magnitude diagrams: The so-called Horizontal Branch of NGC 288 is bluer, and the turnoff point of the main sequence (hottest/bluest/most massive main sequence stars) is redder (and fainter).

Binocular observers can view NGC 288 together with the bright galaxy NGC 253 in one field; NGC 288 appears as a round nebulous object. Telescopes of 4 or 6 inches aperture resolve this cluster, provided the observer is located sufficiently south. The rather poor concentration of this cluster is indicated by its classification in class X.

"NGC 0288 = ESO 474-SC37

00 52 47.4 -26 35 24

V = 8.1; Size 13.8

17.5" (8/29/92): very bright, very large, round, ~8' diameter. Well-resolved over entire disc into 75-100 stars mag 13-15 at White Mountains over background glow although not densely packed. 60 stars resolved at Fiddletown, only weakly concentrated in core.

13" (11/5/83): 30-40 stars resolved over haze.

8" (10/4/80): very large, grainy, few stars resolved at the NW and S edges, other clumps on the verge of resolution.

by Steve Gottlieb."

BLANCO 1

This is a very large and sparse open cluster. It is a sprawling group of stars, some of which are rather bright, the cluster has the mag 5.0 star ζ Sculptoris as its northwestern boundary. This object is best viewed with rich-field telescopes and binoculars. RA 00 03 2.9 DEC-30 00 08.

δ SCULPTORIS

This a multiple star system: AB: 4.6, 11.5; 243º, 4" and C: 9.5; 297º, 75".

ε SCULPTORIS

This system is a slow moving binary with an orbit of about 1200 years: 5.4, 8.6; currently 23º, 4.7".

κ¹ SCULPTORIS

6.1, 6.2; 265º, 1.4".

τ SCULPTORIS

This is another slow moving binary system; it takes nearly 1900 years to make one revolution: 6.0, 7.1; 340º, 2.1".

CLEAR SKIES

References: Astronomy 2004. NGC/IC Database. Burhams Celestial Handbook. The Constellations web page.