|Observation data (J2000 epoch)|
|Right ascension||00h 52m 53.0s|
|Declination||+43° 11′ 45″|
|Redshift||-216 ± ? km/s|
|Distance||2.50 ± 0.08 Mly (766 ± 25 kpc)|
|Notable features||Satellite galaxy|
|And IX, PGC 4689222|
Andromeda IX (And 9) is a dwarf spheroidal satellite of the Andromeda Galaxy. It was discovered in 2004 by resolved stellar photometry from the Sloan Digital Sky Survey (SDSS), by Zucker et al. (2004). At the time of its discovery, it was the galaxy with the lowest known surface brightness, ΣV ≃ 26.8mags arcsec−2 and the faintest galaxy known from its intrinsic absolute brightness.
It was found from data acquired within an SDSS scan along the major axis of M31, on October 5, 2002. Its distance was estimated to be almost exactly the same as that of M31 by McConnacrchie et al. (2005).
- "Results for Andromeda IX". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-11-29.
- McConnachie, A. W.; Irwin, M. J.; Ferguson, A. M. N.; Ibata, R. A.; Lewis, G. F.; Tanvir, N. (2005). "Distances and metallicities for 17 Local Group galaxies". Monthly Notices of the Royal Astronomical Society. 356 (4): 979–997. arXiv:astro-ph/0410489. Bibcode:2005MNRAS.356..979M. doi:10.1111/j.1365-2966.2004.08514.x.
- "NAME Andromeda IX". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-11-29.