Galaxy group in Serpens
This tight group of galaxies was first reported by Carl Seyfert in 1951. Because of its great distance, it appears quite tiny even through a telescope. Years ago I observed it through a 13.1-inch Dobsonian scope, and my notes describe it as a dim glow with hints of an L shape. I could not see the individual galaxies. The overall brightness of the group is about magnitude 13, but the individual galaxies are about magnitude 15 or 16.
Calling this group a sextet is not really accurate, for two reasons. First, one of the six objects (at the lower right) is not a galaxy at all, but rather a "tidal tail"--a distortion of one of the galaxies caused by gravitational interactions. Looking at the larger version of this picture makes it easier to see that this is just an elongated wisp with no central condensation. Second, the small round galaxy that is "inside" the L shape is actually a much more distant background galaxy. Based on its redshift, this spiral galaxy is estimated to be about five times farther away, at a staggering distance of nearly a billion light years.
| Magnitude | 13.3 |
| Apparent Size | 2.2' x 1.2' |
| Distance (light yrs) | 190 million |
| Right Ascension | 15:29.2 |
| Declination | +20 45 |
| Field of View | 29' x 22' |
Image details: Exposure times of 90 minutes luminance, and 36 minutes each of red, green, and blue, taken with an SBIG ST-8300M imager and a 14" Meade LX850 telescope at f/6.
July 2014