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NGC 5664 (12,495 of 18,816)


oc gc pln bn dn gx gxcl ast aka lost




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NGC 5664

NGC 5664, IC 4455, LEDA 52033, MCG-02-37-008

RA: 14h 33m 43.2s
Dec: −14° 37′ 8″

Con: Libra
Ch: MSA:815, U2:287, SA:14

Ref: SIMBAD, Corwin

(reference key)

Type: galaxy (Seyfert 2), Sa

Mag: B=15, V=?

Size: 0.776′ x 0.354′
PA: 30°

History and Accurate Positions for the NGC/IC Objects (Corwin 2004)

NGC 5664 = IC 4455. Here is one which neither the NGC nor the IC get right (see the brief discussion under the IC number for that problem). The NGC observation comes from the first Leander McCormick list of nebulae: the RA is given to a whole minute of time only, and is 42 seconds off; the declination is off by more than 2 arcmin as well. But we do have a sketch showing the galaxy with four nearby field stars. These, along with a moderately useful description ("pF, S, E, gbM") positively identify the object.

Since the position is fairly close (for a Leander McCormick position, anyway), Howe was able to find the right galaxy and give a corrected position in one of his MNRAS articles. Dreyer quotes this in the IC2 Notes, but also repeats the IC1 Note giving a corrected RA from Ormond Stone's 1893 paper "Southern Nebulae". This paper has three micrometric measurements of the object made on two different nights by Muller (one measurement) and Leavenworth (two measurements from about 10 months earlier). They used three different stars, so we are able to intercompare the resulting positions: they all agree with the value given in the IC Notes, and that RA is a minute of time larger than Howe's.

Yet Howe is correct. The approximate positions for two of the Leander McCormick comparison stars are exactly one minute of time too large, while the RA offset (derived from 6 settings!) is one minute of time too small for the other star (for which an accurate and precise position is given). There are too many problems here to be simple typos or transcription errors, and I suspect that the numbers were "adjusted" to agree among themselves.

In any event, the identity is secure.

Published comments

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 15.0 mag galaxy. Their coded description reads USBOVAL.

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