NGC 5278 / NGC 5279 (UGC 8677, Arp 239 / UGC 8678, Markarian 271A) Galaxies in Ursa Major

Located at: RA 13 hours 41 minutes 44 seconds, Dec +55 degrees 40 minutes 23 seconds

Size: 0.8' x 0.6 ' / 0.7' x 0.4' Magnitude: 13.5 / 15.0 Class: SA(s)b? pec / SB(s)a pec

North is up

West to the right

Telescope:

 14.5" f5 Newtonian reflector

Camera:

 ST-8XME, self-guided, binned 1x1, temp -15c & -20c, camera control MaxIm DL 4.56

Image:

Lumicon Red filter, 720 minutes (72 x 10 minute subs), 03/29 & 04/3/7/9/10/2018; seeing 2.4-5.7 per CCDStack

Processing:

CCDStack 2.94.6355.18107, Photoshop CS5.1

Location:

 Rolling Roof Observatory, Thousand Oaks, CA 91360 (+34d 13m 29s -118h 52m 20s)

Notes:

Calling it 'done' on this field ... Between the moon, fog, and high clouds, this is about the best I can do ... I want to move on to new objects.

From the NGC / IC Project:

NGC 5278 = Arp 239 NED1 = VV 19a = UGC 8677 = MCG +09-22-101 = (CGCG 271-058) = (CGCG 272-003) = Mrk 271a = I Zw 69 Notes1 = PGC 48473

13 41 39.7 +55 40 14

V = 12.7;  Size 1.3'x1.0';  Surf Br = 12.8;  PA = 50d

 

18" (4/26/08): fairly faint, small, irregularly round, 30"x25", weak concentration with a slightly brighter core.  The surface appears slightly irregular or mottled.  This is the brighter southwestern member of an interacting double system (Arp 239) with NGC 5279, barely off the east end.  A mag 6.9 star lies 8' ENE, but it was easy to keep it out of the field.

 

17.5" (6/18/93): fairly faint, fairly small, round, 45" diameter, very weakly concentrated core.  Forms a double system with NGC 5279 just off the ENE edge 40" between centers.  A mag 13.5 star lies 1.7' NNW.  Located 8.1' WSW of mag 6.9 SAO 28858.

 

William Herschel discovered NGC 5278 = H II-798 = h1665 on 14 Apr 1789 (sweep 921) and noted "pB, E, 1 1/2' long and 1/2' br."  His position is 2' northwest of this double system.  JH resolved it and recorded "vF; double neb; pos = 73 by microm; a large star follows dist = 15' +/-."  The field was sketched on 9 Apr 1874 at Birr Castle and a "star" labeled "epsilon" actually corresponds with UGC 8671.

******************************

NGC 5279 = Arp 239 NED2 = VV 19b = UGC 8678 = MCG +09-22-102 = Mrk 271b = I Zw 69 Notes2 = PGC 48482

13 41 43.7 +55 40 24

V = 14.2;  Size 0.6'x0.4';  Surf Br = 12.5

 

18" (4/26/08): faint, very small, round, 12" diameter, too small for any other details.  Just resolved off the ENE end of NGC 5278 (35" between centers).  This is an M51-type interacting pair (Arp 239), though there was no sign of the connecting arm.

 

17.5" (6/18/93): very faint, very small, round, 20" diameter, even surface brightness.  Located just off the east edge of larger and brighter NGC 5278.  On photos NGC 5279 appears to be embedded at the end of a spiral arm of NGC 5278.

 

John Herschel discovered NGC 5279 = h1665a on 4 May 1831 and described a "vF; double neb; pos = 73 by micrometer."  WH discovered the brighter southwestern component on 14 Apr 1789.  JH only included only a single entry in the GC (3639), though described this system as a double or bi-nuclear.

 

Lawrence Parsons (the 4th Earl of Rosse) resolved the pair again on 2 May 1872 and noted a "D neb, sp one B, pos 71.8, dist 39".  In the NGC, Dreyer equated NGC 5279 with h1665a and listed LdR* (Lawrence Parsons) in the "Other Observers" column to acknowledge JH's prior discovery.

.