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Type: bright nebula (HII region)
Mag: B=?, V=?
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The complex region NGC 3576/7/89 & NGC 3581/2/4/6, collectively Gum 38a and RCW 57A, is nick-named the Little Tarantula.
NGC 3576. Even though Lauberts marks the identity as questionable, there is no doubt that this is the object that JH saw. His figure shows all six of the bright patches of nebulosity in the area, and matches the appearance of the sky pretty well. He notes that the position for this object (and a couple of others) comes from two figures he sketched for the group. This may account for his RA being a bit off for this southwest patch: it is shown too close to the rest of the nebulae in his figure.
The other nebulae are NGC 3579, 3581, 3582, 3584, and 3586. JH's positions and descriptions for them are very good.
Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "Faint; oval. The first of a group of six."
These six are NGC 3576, 3579, 3581, 3582, 3584 and 3586.
Recorded in "Observations of the Southern Nebulae made with the Great Melbourne Telescope".
See the discussion of Lithograph M.4.35 for the details.
Region around Eta Argo. Union Obs. Circ., No 18, 123-125.
Ced 113a (NGC 3576)
Position (1900): RA 11 7.6, Dec - 60 50
Star: -60 2631? (Mp=9.2, V=9.2, SpT=B4)
Spectrum of nebula: continuous spectrum (inferred from sp.t. of illuminating star)
Classification: Nebulous cluster (Patches of neb adhering to individual stars of the cluster, eg. Pleiades)
Size: (not given)
Notes: "Ced 113 A nebulous field discovered by John Herschel in 1834 and catalogued as follows. Ced 113 a = NGC 3576 = GC 2333 = h 3324, R. CPD -60 2631 = HD 97452 may be the light-source."
A Preliminary Survey of Nebulosities and Associated B-Stars in Carina.
Gum, C.S. (1955) A survey of southern HII regions. Mem.RAS, 67. [1955MmRAS..67..155G]
A Survey of Southern H II Regions published in the RAS Memoirs, Vol. LXVII, identifies his No. 38a with this grouping. Gum 38b is NGC 3603, and he writes: "Two objects linked together with nebulosity (overall dimensions 45' x 15'). Each is of complex structure." For his 38a grouping, he gives the size as 20' x 15' and identifies the group with No. 113 in Sven Cederblad's 1946 catalogue. The combined grouping of Gum 38a + b are also known as RCW 57, which is commented with "Appears obscuration-bounded and contains bright crescent shaped region 50' x 20'."
Sher, D. () "Structure of the Milky Way in Carina" QJRAS, v 6, p 299-320.
p310: "The various parts of the complicated and rather striking nebuloisty about a degree to the south of Tr 18 are known by several catalogue numbers ... The southernmost parts of the nebulosut are bright and amorphous. To the north the nebulosity is arranged in prominent loops or 'smoke rings' Following NGC 3576 in the sky,m and apparently linked to it by faint nebulosuty, is the cluster and small bright H-alpha region listed togther as NGC 3603. NGC 3576 and NGC 3603 are recorded by Gum as Nos. 38a and 38b resp. ... There is no indication of any clustering of stars in the region of NGC 3576 on plates taken with the 20/26 inch Schmidt telescope."
(Sulentic and Tifft 1973) notes that this is a diffuse nebula.
by Jim Lucyk: Astronomy mag. 6/88 p6-7.
NGC 3579 & NGC 3581 & NGC 3582 & NGC 3584 & NGC 3586
QBS: one lg mess. 15cm descr correct as far as it goes. a seventh patch is ~5' W of m9 * nr -81/82, surrounds m11 *.
15cm - a grp of five more-or-less distinct emission nebs, much enhanced by[OIII], less so by UHC. brtst patch lies immed W of m10 * (-81). it fans N from m12.5 * w/two vf comps. dims out before reaching -82 NNE, which is circ spot immed E of m12 *. these two are 3'x2', elong NNE-SSW. -79 & -84 lie to N sep by narrow dk lane btwn them and -81/82 running ENE-WSW. -79 is fntr, circ. -84 has a ray extending N. SE of -81/82 is -86, past a m12 *. due S of -81/82 is wk patch elong N-S w/o an NGC number. SW, nr a m12 *, is a vsm circ spot, -76. BS, 22Feb1990, LCO.
The Messier objects
The Bennett objects
The Caldwell list
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