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Type: galaxy, E...
Mag: B=11, V=?
Size: 6.309′ x 4.365′
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Synonyms: H I-259
Discovered in 1791 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "cB, pL, lE, gbM. The brightness takes up a large space of it."
Observed by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "pB, E, mbM, very resolvable, 20 arcseconds, has a very small star S.p. involved." On a second occassion he called it "B, pL, lE, glbM, 80 arcseconds long, 50 arcseconds broad, resolvable."
vBEN with B, pS atmosphere E 45deg.
vBN with atm. falling off in intensity like a globular nebula. The arm. extends about 3'x1' E 50deg.
The RNGC (Sulentic and Tifft 1973) notes that this is a 11.5 mag galaxy. Their coded description reads SO),SLEL,SBM,DIF.
G. de Vaucouleurs ("Galaxies and the Universe", Chapter 14 - Nearby Groups of Galaxies) notes that the five brightest members of the NGC 3923 Group are NGC 3923, NGC 4105, NGC 3904, IC 764 & NGC 4106.
Photo Index by Jim Lucyk: Sky&Tel. 12/86 p584.
Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "11.1M; 2' x 1' extent; oblong with brighter center; almost stellar nucleus; nearby, soft EL GAL N3904 is just 35' to SW."
Steve Coe (1992, The Deep-Sky Observer, Webb Society, Issue 1) observing with a 17.5-inch f/4.5 at 100x notes: "bright, elongated, pretty large, averted vision helps."
Houston includes this galaxy in his Hydra Hysteria.
POSS: m13 * 1'.78 SW, W of maj axis; other * (red) 3'.47 from center sl E
of maj axis. * 24" W/sl S of center seems to have dk area interior
to it, but looks like adjacentcy effect. sl disturbance evident at
NE end of core (a br patch). damn he's good!
QBS: interior vsmooth, no dk patch. sorry boss! also no br spot NE end of
core. SA(r)0- [BS]. gx E440-G27 (B=13.2) 33'.6 NE.
SGC: SAB(s)0-? pec
15cm - lgr & brtr than -04 SW, and more interesting @ 140x. vlg vlosfcbr halo
4'x3' elong NE-SW. core 1'.2x0'.8 in pa55. halo reaches past m13 * on
maj axis SW, but not as far as sim-br * NE also on axis. core has m14 *
(?) on W edge; btwn here & *ar nuc is dk patch. nuc vbr even over br
core. at NE end of core is sub*ar spot, giving core dbl nature---or
triple w/f * on W. rough sketch in notes. BS, 27Feb1990, LCO.
Date: 7 6 1997
Very small galaxy Faint. Bright nucleus Hazy around. Soft light.
8-inch f/10 SCT (EP: 1.25-inch 26mm SP 77x 41' fov; 1.25-inch 18mm SW 111x 36' fov)
Very faint and small glow of light. Brightens slowly to the soft yet strong nucleus, but not star like. Slight oval in appearance from northeast to southwest. To the south as well as the south east of the galaxy inside the star field are a few outstanding stars that attract attention. (Mag 9.6; size 6.9' x 4.8'; SB 13.3; PA 46)
Sutherland (Huis Lana)
"Bertha" 12-inch f/4.8 Dobsonian (EP: 32mm, 25mm, 10mm, 6.3mm Plossls, 2x Barlow, 32mm Erfle)
Conditions: Clear, dark.
About midway between Corvus and xi Hydrae lies the spiral NGC 3923. 60x: Bright elongated glow, oriented NE-SW, positioned in line with three small stars. 120x, 150x: Bright central region (E 1:1.3) with elongated (E 1:3) halo. From sketch: small star on SSW tip. Overall, the galaxy measures 2.7' x 0.9', with a brighter central region 1.0' x 0.8'. Sketch shows nearby field stars. (D: 20090129/30. Own star charts)
Sky Conditions:The fainter parts of the Milky Way are barely visible.Haziness only visible on the horizon.Atmosphere stable with little interference.
NGC 3923's oval disk looks exactly like an almost flat rugby ball which is seen as an out of focus glow of white light.At 75x the central core of this galaxy is moderately condensed and I have noticed that the core of this galaxy is brighter compared to the far outskirts of this object.This galaxy measures 4'x 2.8'with P.A:SW/NE.
The Messier objects
The Bennett objects
The Caldwell list
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