|Observation data (J2000 epoch)|
|Right ascension||13h 15m 30.31s|
|Declination||+47° 29′ 56.2″|
6.03 / 8.23 Mpc|
(19.7 / 26.8 million ly)
|Apparent magnitude (V)||14.61|
|Apparent size (V)||2.7′ × 0.9'|
|UGC 8331, PGC 46127|
DDO 169 (also known as UGC 8331) is an irregular galaxy located in the constellation Canes Venatici. It is a member of the M51 Group of galaxies and measures approximately 5 × 1.5 kiloparsecs (16,000 × 5,000 lightyears). The galaxy's large-scale structure is very unorganized and it has two clusters of stars in its outer portions in addition to the cluster in the center. These clusters make it practically impossible to determine the galaxy's rotation curve and contributes to a large variation in distance figures that are derived with different methods. The exact distance to the galaxy is not known, although a 1998 paper estimated the distance as 8.23 megaparsecs.
- "NED results for UGC 8331". NED via University of California. Retrieved 2009-03-08.
- I.D. Karachentsev; I.O. Drovdozsky (July 1998). "Distances to five resolved galaxies in the Canes Venatici cloud" (PDF). Astronomy and Astrophysics Supplement Series. Retrieved 2009-03-08.[permanent dead link]
- R.A. Swaters; R. Sancisi; T.S. van Albada; J.M. van der Hulst (2009-01-27). "The rotation curves shapes of late-type dwarf galaxies". Astronomy and Astrophysics. 493: 871–892. arXiv:0901.4222. Bibcode:2009A&A...493..871S. doi:10.1051/0004-6361:200810516.