(IAAC) NGC 7578 / HCG 94 - Newtonian 17.5" (445mm) F/4.5

[Yann POTHIER]

Observer: Yann POTHIER (France)
Your skill: advanced (many years)
Object: NGC 7578, HCG 94, Arp 170, VV 181
Category: cluster of galaxies
Constellation: CAP
Object data : composed of PGC 70933 (HCG94B, UGC 
12477), PGC 70934 (HCG94A, UGC 12478), PGC 70936 
(HCG94D) & PGC 70943 (HCG94C), Bmags= 
14.95+14.70+16.33+16.19, dimensions= 
1.4'+1.0'+0.3'x0.2'+0.7'x0.3';
RA/DE: 23h17m12.0s, +18°42'04"; 23h17m13.5s, 
+18°42'27"; 23h17m15.2s, +18°42'42"; 23h17m20.2s, 
+18°44'05"  (2000.0)
Date and UT of observation: 12 august 2007, 02h30 UT
Location & latitude: La Clapiere Obs. (France, latN44 40 00, longE06 27 36)
Site classification: rural, alt.1650m (5500ft)
Limiting magnitude (visual in UMi): 6.31 (30% of the time)
Transparency (1 to 5 - best to worst): 1
Seeing (1 to 5 - best to worst): 2
Height above horizon: 61°
Moon up (phase?): no
Instrument: Coulter 445mm (17.5"), F/4.5
Magnification: 80-426x
Filters used: -

Description: at 271 and 426x, nice group of 4 
galaxies in line on a 3' segment NE-SW, seen 
together 50% of the observing time at 80x like a 
faint unresolved open cluster; from SW to NE are 
to be found :
PGC 70933 (HCG94B), very small, extremely faint, 
seen about 5% of the observing time at 271x, 
round, about 15" in ø (0.25'), homogeneous with 
diffuse edges; mag.14 star is at 0.8'ESE.
PGC 70934 (HCG94A), 35" to the NE, very small, 
very very faint, seen about 25% of the observing 
time at 271x, round, about 34" in ø (0.56'), with 
a brighter center.
PGC 70936 (HCG94D), 24" to the NE, extremely 
small, extremely faint, seen about 1% of the 
observing time at 271x (a few glimpses), observed 
from 271 to 426x; round, about 8" de ø (0.13'), 
homogeneous with diffuse edges; mag.16 star just 
against the border, less than 5"SSW distant 
(between this galaxy and the preceding).
PGC 70943 (HCG94C), 1.8' to the NE, very small, 
extremely faint, seen a few % of the observing 
time at 271x, observed from 271 to 426x; oval, 
15"x10" (0.24'x0.16') NNW-SSE, homogeneous with 
diffuse edges.


-- 

Carpe noctem, Yann.

Yann Pothier
11 impasse Canart, 75012 PARIS, FRANCE
yann.pothier at fnac.net
http://www.astrosurf.com/cielextreme