NGC/IC Project Restoration Effort

===== NGC 7578. The modern catalogues make a small mess of this NGC number, so here are the facts in RA order (the positions are from HKA): RA (1950.0) Dec Hickson VV UGC RC2/3 23 14 42.50 +18 25 39.5 94b=N7578A 181b 12477=N7578a N7578A 23 14 44.00 +18 26 04.4 94a=N7578B 181a 12478=N7578b N7578B Hickson and VV did things logically (by magnitude), choosing the brightest component as "a". UGC followed its internal scheme, also logical, of choosing component letters by RA. RC2/3 followed UGC. Looking at the NGC, we see that N7578 was only observed by William and John Herschel. Though WH noted "4 or 5 small stars with nebulosity," JH saw only one object here which he succinctly described with a single letter "F." Neither of their positions is good enough to pin down one or the other of the galaxies as the real N7578, but since Hickson 94a is brighter by over 0.6 mag, I think that we can choose it as N7578 without bending the history too much. So, I have ignored the NGC identifications in Hickson, UGC, and RC2/3; and have made the brighter north-following object (UGC 12478) = NGC 7578. This group, by the way, may also be NGC 7571, which see.

===== NGC 7578 48" (10/27/16): at 488x; bright, fairly small, round, sharply concentrated with a very bright core that gradually increases to the center and a low surface brightness ~30" halo. A mag 14.5 star is at the NE edge [17" from center]. Forms a bright double system with NGC 7578A = HCG 94B 0.6' SW. The companion appeared fairly bright, small, round, sharply concentrated with a very bright core increasing to small intense nucleus. HCG 94D, just northeast of the mag 14.5 star, is faint to fairly faint (V = 16.1), very small, round, 8" diameter, even surface brightness. HCG 94C, the third brightest (V = 15.1) and perhaps the largest in the septet, is 2.2' NE. It appeared moderately bright and large, very elongated at least 3:1 NNW-SSE, ~30"x10", well concentrated with a sharp bright nucleus. HCG 94F, just 0.5' NW, is very faint (V = 17.0), very small, slightly elongated, 8"x6". HCG 94G, 0.9' N of HCG 94C, is an extremely small, very faint glow (V = 17.2), only 6" diameter. Completing the septet is HCG 94E, 1.2' NNE of NGC 7578. This extremely faint (V = 16.9) edge-on extends 0.4'x0.1' and has a very low even surface brightness. The observation was made through thin clouds. This septet lies at a distance of ~570 million light years. 24" (8/14/15): at 375x; fairly faint to moderately bright, small, round, 24" diameter, very small bright nucleus. A mag 14.5 star is just off the northeast side [17" from center]. Forms a double system with NGC 7578A = HCG 94B just 34" SW. The companion appeared fairly faint, small, round, 20" diameter, contains a very small, bright nucleus. NGC 7578C = HCG 94D, just 27" NE, is the faintest of 4 in HCG 94 and appeared extremely faint and small, round, only 6" diameter, visible only part of the time. Finally HCG 94C lies 2.2' NE and appeared faint to fairly faint, small, elongated at least 3:2 N-S, contains a small brighter core and very faint extensions NNW-SSE, 18"x10". The quartet (along with the mentioned star) are in a 2.8' linear string oriented SW-NE. 24" (8/16/12): at 376x the brightest member of HCG 94 appeared moderately bright, very small, round, 25" diameter, fairly high surface brightness, very small bright nucleus. A mag 14.5 star is barely off the northeast end. Forms a close pair with HCG 94B (34" between centers) with HCG 94D only 24" NE (very close to the mag 14.5 star). HCG 94B (NGC 7578A) appeared fairly faint, very small, round, 20" core surrounded by a very low surface brightness halo. HCG 94D (NGC 7578C) appeared extremely faint and small, round, 6" diameter. HCG 94C lies 2.2' NE and appeared faint, small, elongated 2:1 ~N-S, contains a very small slightly brighter core and faint extensions NNW-SSE, ~20"x10". A mag 14 star lies 50" S. 18" (8/25/06): this is the northeast component of a double system in HCG 94 (core of AGC 2572). It appeared faint, very small, round, 0.4' diameter with a mag 14.5 star just off the NE end. 18" (9/3/05): fairly faint, very small, round, 25" diameter. A mag 14 star is very close at the NE edge and somewhat confuses the view. Forms a double with slightly fainter HCG 94B just 0.6' SW of center. The SW component appeared faint, very small, round, 20" diameter. 18" (8/27/05): at 323x, this double system is cleanly resolved. The NE component is faint, very small, round, 20" diameter. A mag 14-15 star is just off the NE end and a second mag 14 star lies 50" south. Just separated from HCG 94B, which lies 34" SW of center. 17.5" (9/7/96): fairly faint, small, round, 45" diameter. A mag 14 star is at the NE edge and a second mag 14 star 0.9' S. Forms a double system with UGC 12477 = HCG 94b on the SW side of the halo. The brighter cores of the galaxies are cleanly resolved but both appear to be encased in a common outer halo. The faintest member, HCG 94c, lies 2.2' NE. HCG 93 lies only 32' NW! 17.5" (9/23/89): this is the brightest member of the HCG 94 compact group in AGC 2572 (identified as NGC 7578B in RC2, UGC and HCG). Faint, small, slightly elongated SW-NE. Attached to fainter NGC 7578A = HCG 94b just 34" SW of center in a common halo. A mag 15 star is at the NE edge 15" from center and a mag 14 star is off the south side 52" from center.