NGC 3169, NGC 3166, and NGC 3165
Galaxies in Sextens

NGC 3169, NGC 3166, and NGC 3165 (left to right in the Kopernik image above) form a peculiar and probably interacting group of spiral galaxies in the constellation of Sextans. They all have approximately the same red shift and radio observations show them to be inside a common envelope of neutral hydrogen. The warped plane of NGC 3169 and the peculiar morphology of NGC 3166 almost certainly verify that tides from a close encounter have occurred.

NGC 3169 has a small bright nucleus and multiple dust lanes that appear in silhouette against the large central bulge. The spiral arm pattern is of the filamentary type. H-II regions are evident, particularly in the bright arm on the near side. Very faint outer arms exist of such low surface brightness that they are only hinted at in the Kopernik image. When the image was taken NGC 3169 was the host of Supernova 2003 cg (See our SN 2003 cg page.)

NGC 3166 is a strange Spiral Galaxy with a very small, very bright nucleus in a short smooth bar (0.5' x 0.14'). The spiral pattern is only in the lens, and there is a large very faint extended envelope.

NGC 3165 is a small and dim Spiral Galaxy that is also a member of the group.

Using the red shift data from the “NASA Extra-galactic Data Base(NED)”, (and a Hubble Constant of 62 Km per sec., per Megaparsec), one can calculate a rough distance estimate of 65 million light years for this galaxy group.

NGC 3169 Magnitude: 11.5 Constellation: Sextans RA: 10h 14m 14.3s Dec: +03° 28' 08" Epoch 2000 Size (mins): 4.4' x 2.8' Classification: Spiral, S-shaped, peculiar Deep Sky Field Guide to Uranometria 2000:        "Small, very bright nucleus in bright bulge; with dark lane on one side."	NGC 3166 Magnitude: 11.3 RA: 10h 13m 44.9s Dec: +03° 25' 31" Epoch 2000 Size (mins): 4.8' x 2.4' Classification: Mixed Barred Non-Barred Spiral, Mixed Inner Ring - S-Shaped, LINER type Active Galactic Nucleus Dreyer's Description in the NGC:     "Bright, pretty small, round, westward abruptly much brighter middle, 2nd of 3."
NGC 3165 Magnitude: 14.0 RA: 10h 13m 31.4s Dec: +03° 22' 32" Epoch 2000 Size (mins): 1.6' x 0.8' Classification: Spiral Galaxy, S-Shaped, (uncertain) Dreyer's Description in the NGC:     "Very faint, moderately extended 0°, 1st of 3."

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George Normandin, KAS

June 11th, 2003