U 368
11:40 to 12:20
-28° to -39°
Cen, Hya

FEATURED OBJECTS: NGC 3923 (Ben 49) , NGC 4105 , NGC 3904 , NGC 4106 .

NGC 3923
Bennett 49
ESO440-G017
RA 11:51:02
Dec -28° 48.4'
Galaxy

Discovered in 1791 by William Herschel (H I-259): "cB, pL, lE, gbM. The brightness takes up a large space of it."

h: "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."

Tom Lorenzin: “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."

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.

NGC 4105
ESO440-IG054
RA 12:06:40
Dec -29° 45.7'
Galaxy

Discovered in 1791 by William Herschel (H II-865) "Two nebulae [NGC 4105 & NGC 4106] both F, S, R, bM, and nearly in the same parallel."

h: "the first of a double nebula (pos 111.2 degrees) B, R, pL, psbM, resolvable, 25 arcseconds. The difference in RA of this nebula and a star south of it = 2.0 seconds." On a second occassion he wrote: "pF, R, gbM, 30 arcseconds, resolvable. The first of a double nebula, pos = 120.3 degrees." The other object is NGC 4106.

Hartung notes: “In a star sprinkled field are two fine round nebulae [NGC 4105 & NGC 4106] with their concentrated centres about 1.5’ apart. They are clear though faint with 10.5cm and form a triangle with a star about 2’ south.”

Houston includes this galaxy in his Hydra Hysteria. He notes that it is about 2' long and is slightly larger than its nearby companion, NGC 4106, 1' to the east. He adds that both appear of similar magnitude. In 1972 he wrote: "a pair of elliptical 11th mag galaxies . . visually each is about 0.5' in diameter, and their cores are separated by about 1'. In a 2-inch scope at low power the two galaxies form a single image but in a 6-inch they are well separated."

Steve Coe (1992, The Deep-Sky Observer, Webb Society, Issue 1) observing with a 17.5-inch f/4.5 at 100x notes: "pF, R, pS, a little larger than NGC 4106."

Tom Lorenzin: “12M; 1.5' diameter; faint, small EL GAL with brighter center; EL GAL N4106 (12.5M; 1' diameter) 1.1' distant; interacting pair.”

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.

Van den Bergh (1961, Astronomical Journal, Vol 66, p566) notes that this galaxy forms a pure pair with NGC 4106 1.3 arcminutes away.

NGC 3904
ESO440-G013
RA 11:49:11
Dec -29° 16.6'
Galaxy

Discovered in 1791 by William Herschel (H II-864) "pB, S, R, vgmbM, almost resembling a nucleus."

h: "pB, R, psmbM, 15 arcseconds."

Houston includes this galaxy in his Hydra Hysteria. He notes that it is an elliptical galaxy, about 2' in diameter and 11th magnitude.

Steve Coe (1992, The Deep-Sky Observer, Webb Society, Issue 1) observing with a 17.5-inch f/4.5 at 100x notes: "pB, pS, somewhat elongated, BM."

Tom Lorenzin: “11.9M; 1.5' x 1' extent; bright, small oblong with brighter center; see brighter EL GAL N3923 35' to NE.”

A supernova erupted in this galaxy in 1971 (15.3v)

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.

NGC 4106
ESO440-G056
RA 12:06:44
Dec -29° 46.1'
Galaxy

Discovered in 1791 by William Herschel (H II-866): "Two nebulae [NGC 4105 & NGC 4106] both F, S, R, bM, and nearly in the same parallel."

h: "the second of a double nebula. B, R, pL, psbM, resolvable, 25 arcseconds." On a second occassion he called it "F, R, gbM, 20 arcseconds, resolvable, the second of a double nebula." The other object is NGC 4105.

Hartung notes: “In a star sprinkled field are two fine round nebulae [NGC 4105 & NGC 4106] with their concentrated centres about 1.5’ apart. They are clear though faint with 10.5cm and form a triangle with a star about 2’ south.”

Houston includes this galaxy in his Hydra Hysteria. He notes that NGC 4105 lies 1' to the west, and adds that both galaxies appear of similar magnitude.

Steve Coe (1992, The Deep-Sky Observer, Webb Society, Issue 1) observing with a 17.5-inch f/4.5 at 100x notes: "pF, R, pS, averted vision helps."

Tom Lorenzin: “12M; 1.5' diameter; faint, small EL GAL with brighter center; EL GAL N4106 (12.5M; 1' diameter) 1.1' distant; interacting pair.”

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. Van den Bergh (1961, Astronomical Journal, Vol 66, p566) notes that this galaxy forms a pure pair with NGC 4105 1.3 arcminutes away.