NGC 691 Galaxy Group
History
The galaxies NGC 678, NGC 680 and NGC 697 were discovered on September 15, 1784 by the German-British astronomer William Herschel with his 18.7 inch reflecting telescope. He did not come across NGC 691 until November 13, 1786. The discovery of NGC 694 by the German astronomer Heinrich d'Arrest did not take place until December 2, 1861. He used an 11 inch refractor telescope. IC 167 was discovered on January 4, 1889 by the French astronomer Guillaume Bigourdan with a 12.4 inch refractor. The tail light of this discovery round is IC 1730 which was discovered on January 17, 1896 by the French astronomer Stephane Javelle with the 76 cm refractor telescope of the Observatoire de Nice. [196, 277]
Physical Properties
These galaxies belong to the NGC 691 galaxy group, which is located approximately at a distance of 27.8 Mpc to 40.9 Mpc from us. Some sources also include NGC 695 in this group, but their distance is about 135 Mpc, which means it is far in the background. [145]
| Name | RA [hms] | Dec [dms] | mType | Dim ['] | Btot [mag] | HRV [km/s] | PA [°] |
|---|---|---|---|---|---|---|---|
| NGC 678 | 01 49 25.2 | +21 59 51 | SB | 4.1 x .8 | 13.3 | 2836 | 78 |
| NGC 680 | 01 49 47.3 | +21 58 14 | E | 1.8 x 1.6 | 12.9 | 2808 | |
| IC 1730 | 01 49 58.0 | +21 57 52 | L M | .8 x .5 | 15.3 | ||
| NGC 691 | 01 50 41.7 | +21 45 35 | S R | 3.4 x 2.5 | 12.3 | 2665 | 95 |
| NGC 694 | 01 50 58.1 | +21 59 50 | C | .6 x .4 | 14.3 | 2949 | 160 |
| IC 167 | 01 51 08.3 | +21 54 50 | SB | 2.7 x 1.8 | 13.6 | 2935 | 95 |
| NGC 697 | 01 51 17.2 | +22 21 32 | SB | 4.4 x 1.4 | 12.8 | 3117 | 105 |
Finder Chart
The NGC 691 galaxy group can be found in the constellation Aries. The best time to observe is August to February, when it is highest at night.
