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NGC 4661 (10,195 of 18,816)

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NGC 4661 (Centaurus Chain 1)

NGC 4661, NGC 4650B, ESO 322-71, ESO 322-72, LEDA 42966, MCG-07-26-039 (in Centaurus Chain 1), h 3415, GC 3194

RA: 12h 45m 14.8s
Dec: −40° 49′ 26″

Con: Centaurus
Ch: MSA:935, U2:402, SA:21

Ref: SIMBAD, Corwin (2004)

(reference key)

Type: galaxy (in cluster), E

Mag: B=16, V=15.17

Size: 0.707′ x 0.676′
PA: 10°

Historically-aware NGC/IC Positions and Notes (Corwin 2007)

NGC 4661 has often been referred to in the literature as "NGC 4650B". At first glance, we might think this alternate designation comes from deV's "Stromlo 13" monograph on the southern Shapley-Ames galaxies. But there is no trace of it there.

"NGC 4650B" does appear, however, in RC2. Tracing it back from there leads to a paper in Astrophysics and Space Science (volume 19, page 387, 1972) by J. L. Sersic and E. L. Aguero -- who refer to it only as "G7" in a southern chain of galaxies. So, the awkward notation does indeed originate in RC2 (sigh). My guess is that Antoinette noticed that it and "G5" are near NGC 4650 and, following Gerard's example, put "NGC 4650A" on "G5" and "NGC 4650B" on "G7".

So how did everyone miss the original NGC number? The NGC declination is 17 arcmin in error, but is not marked as uncertain, nor is it truncated as many of the NGC positions are. The only indication in GC that something is amiss is the number of observations used: "1::". Otherwise, that, too, is given to the usual full precision that JH adopted.

Going on back to the CGH observations, though, we find that JH has only one observation of the galaxy in June of 1834, just a few months after his arrival at the Cape. And the position there is given only to a full minute of time in RA, and an arcminute in NPD. Both are marked with plus-minus signs, and JH has no notes of explanation.

Given that, and the fact that "NGC 4650B" is the only galaxy around that JH could have reasonably seen -- his object nearly identifies itself in spite of the crude position.

Historical observations

John Herschel (1847) Cape Observations

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "F, R, pL, gbM."

Published comments

Sulentic & Tifft (1973)

(Sulentic and Tifft 1973) notes that this is a galaxy. Their coded description reads E,ALMSTEL.

Bergwall et.al. (1978)

NGC 4650B: Bergwall et.al. (1978(Astron. Astrophys. Suppl. 33, 243-255) gives this galaxy's B-magnitude in the Johnson system as 14.5. They remark: "In Cen I group. Vo = 2262 kms-1."

Paturel et al. (1991)

Paturel, G., Petit, C., Kogoshvili, N. et al. (1991) An extragalactic data base. IV. Errors and misprints in catalogues of galaxies. Astrophys.J.Suppl.Ser., 91(3), 371.

NGC 4661 = MCG -7 -26 -40.

NGC 4661 = ESO 322-72, not ESO 322-71.

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