DescriptionImages

Object name: NGC7765

Designation(s): NGC7765, NGC7766, NGC7767, NGC7768, CGCG_477_016, ABELL2666,

NGC 7768 is the cD elliptical galaxy that anchors the Abell 2666 cluster. It has far fewer globular clusters than would be expected for a galaxy of its size and location. The cluster is about 350 million light years distant and located in the northeast part of the Great Square of Pegasus. As Abell clusters go this is a small one. In the annotated image I've noted those that are likely true members of the cluster by showing their catalog name. As space was tight and galaxies have many different catalog entries I usually used the shortest to keep clutter down. It was discovered by John Herschel on September 5, 1828.

While several of the galaxies show signs of interaction the most distorted is CGCG 477-016 at the top center of my image. NED simply classes it as a LINER spiral. No mention of the huge, faint plume going west (right) from the southern end of the galaxy. A note at NED isn't so silent about this galaxy saying:
"This galaxy is also probably not a classical ring galaxy. The brightest isophotal levels of the optical and IR images (Fig. 11) show a very peculiar "theta-shaped" system, with a faint bar (which is quite prominent in the IR) and peculiar filaments extending from the ends of the bar. The galaxy shows intense star formation in the regions of the closed portion of the theta-shape. With the exception of the Seyfert rings, this galaxy is one of the few in the sample which showed H{alpha} emission in its nucleus. The most remarkable feature of this galaxy is the huge plume and ripples in the outer regions of the galaxy seen in the blue at low isophotal levels. This suggests that the system is a merger remnant like NGC 7252 (the so-called "Atoms for Peace" galaxy of Whitmore et al. 1993). We are unaware of any major companion near LT 36, and so if the plume and ripples are part of the debris of a highly disrupted companion, there is no sign of the nucleus of the accreted object."
http://adsabs.harvard.edu/cgi-bin/bib_query?1997AJ....113..201A

I'm going to possibly disagree with the last statement above. Looking at the plume it seems to curve behind the galaxy then come up about the middle and arc over to dive into the gap in the theta structure on the western side. That part that dives in is bright and seems to have a star-like "core". Could this be the trail a colliding galaxy followed with the remains of it the bright part of the arc? Is the starlike core then the remains of the core of this galaxy? No paper suggested this so likely not the case but it sure gives that appearance to me.

NGC 7765 was found by R.J. Mitchel on October 12, 1855.
NGC 7766 and NGC7767 were found by Ralph Copeland on October 9, 1872.

Galaxies too distant (none were closer) to be a member of the cluster are just labeled with a G plus their distance in billions of light-years. NED listed no quasar or quasar candidates in the field. Many interesting galaxies had no redshift data. Most weren't even listed at NED. I left those few that were at NED without a label. While the field has been imaged in the DR8 data release NED is yet to pick up the data. When that is included I assume many more will have redshift data.

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designation(s):

2MASS J23504748+2717168, 2MASS J23505214+2709586, 2MASS J23505242+2709583, 2MASS J23505589+2707350, 2MASS J23505636+2705136, 2MASS J23505853+2708503, 2MASX J23504749+2717167, 2MASX J23505214+2709587, 2MASX J23505589+2707347, 2MASX J23505634+2705137, 2MASX J23505859+2708507, 2MASXi J2350474+271716, 2MASXi J2350521+270958, 2MASXi J2350558+270734, 2MASXi J2350563+270513, 2MASXi J2350585+270850, 2MFGC 17897, ABELL 2666, ABELL 2666:[BTM97] 1, ABELL 2666:[CAC2009] BCM, ABELL 2666:[CBW93] A, ABELL 2666:[H80c] 003, ABELL 2666:[H80c] 004, ABELL 2666:[H80c] 005, ABELL 2666:[H80c] 006, ABELL 2666:[H80c] 007, ABELL 2666:[HO98] 201, ABELL 2666:[HO98] 202, ABELL 2666:[HO98] 205, ABELL 2666:[HO98] 210, ABELL 2666:[L84] G1, ABELL 2666:[MS77] 01, ABELL 2666:[MS77] 02, ABELL 2666:[MS77] 03, ABELL 2666:[PL95] BCG, ABELL 2666:[WCB96] B, ABELL2666, AGC 330953, AGC 330954, AGC 331546, ALFALFA 2-466, CAN 084, CAN 084 NED01, CAN 084 NED02, CGCG 2348.2+2654, CGCG 2348.2+2701, CGCG 2348.3+2649, CGCG 2348.3+2651, CGCG 2348.4+2653, CGCG 477 016, CGCG 477-015, CGCG 477-016, CGCG 477-017, CGCG 477-018, CGCG 477-019, CID 84, GALEXASC J235047.45+271718.0 , GALEXASC J235052.16+270958.6 , GALEXASC J235055.89+270736.7 , GALEXASC J235056.38+270513.7 , GALEXMSC J235047.43+271717.3 , GALEXMSC J235052.16+270958.7 , GALEXMSC J235055.93+270735.2 , GALEXMSC J235056.35+270514.6 , GIN 738, GIN 739, HDCE 1256 NED001, HDCE 1256 NED002, HOLM 818A, HOLM 818B, HOLM 818C, HOLM 818D, IRAS F23482+2700, KUG 2348+270A, LDCE 1595 NED008, LDCE 1595 NED009, LT 36, MCG +04-56-014, MCG +04-56-015, MCG +04-56-016, MCG +04-56-017, MCG +04-56-018, NGC 7765, NGC 7766, NGC 7767, NGC 7768, NGC7765, NGC7766, NGC7767, NGC7768, NPM1G +26.0551, NSA 152757, NSA 152758, NSA 152759, NSA 152761, NSA 171229, NVSS J235047+271727, PGC 072596, PGC 072600, PGC 072601, PGC 072605, PGC 072611, RASSCALS SRGb 046, SCL 215 NED02, SDSS J235058.55+270850.4, UGC 12805, UGC 12806, USGC U858 NED05, USGC U858 NED06, USGC U858 NED07, UZC J235047.5+271716, UZC J235056.4+270513, UZC J235058.6+270849, WBL 724-001, WBL 724-002, WBL 724-003, WBL 724-004, WBL 724-005, ZwCl 2335.5+2449 NED02, [AO95] 2348+2700, [M98j] 265 NED02, [M98j] 265 NED03, [MO2001] J235047.5+271715.7,