The Triangulum subgroup is made up of the Triangulum Galaxy (M33) and its satellites. Although the Triangulum Galaxy does not have any proven satellite galaxies, a number of galaxies are suspected of being in the system.
Andromeda XXII
editAndromeda XXII is located much closer in projection to M33 than M31 (42 kiloparsecs (140 kly) vs. 224 kiloparsecs (730 kly)). This fact suggests that it might be the first Triangulum (M33) satellite ever discovered. However, it is currently catalogued as a satellite of Andromeda (M31).[1]
Pisces Dwarf
editPisces Dwarf is an irregular dwarf galaxy that is part of the Local Group. The galaxy is also suspected of being a satellite galaxy of the Triangulum Galaxy.[2]
Andromeda II
editAndromeda II is a dwarf spheroidal galaxy about 2.22 Mly away in the constellation Andromeda. It is part of the Local group of galaxies and is a satellite galaxy of the Andromeda Galaxy (M31) but it is also situated closely to the Triangulum Galaxy (M33), it is not quite clear if it is a satellite of the one or the other galaxy.
Pisces VII
editPisces VII, also known as Triangulum III, is an ultra-faint dwarf galaxy in the constellation of Pisces.[3] Its distance has been found to be 2.99 Mly, meaning it is likely associated with the Triangulum Galaxy.[4]
Data
edit| Name | Type | Distance from Sun (million ly) |
Magnitude | Year discovered |
|---|---|---|---|---|
| Triangulum Galaxy | Spiral Sc | 2.88 | +6.27 | 1654? |
| Triangulum I (Andromeda XXII) | 2009 | |||
| Pisces Dwarf | Elliptical E3 | 2.51 | 1976 | |
| Andromeda II | Elliptical E3 | 2.13 | +13 | 1970 |
| Pisces VII (Triangulum III) | Dwarf UFD | 2.99 | 2021 |
References
edit- ^ Nicolas F. Martin, Alan W. McConnachie, Mike Irwin, Lawrence M. Widrow, Annette M. N. Ferguson, Rodrigo A. Ibata, John Dubinski, Arif Babul, Scott Chapman, Mark Fardal, Geraint F. Lewis, Julio Navarro, R. Michael Rich; "PAndAS' cubs: discovery of two new dwarf galaxies in the surroundings of the Andromeda and Triangulum galaxies"; The Astrophysical Journal, Volume 705, Issue 1, pp. 758-765 (2009); doi:10.1088/0004-637X/705/1/758; Bibcode:2009ApJ...705..758M; arXiv:0909.0399;
- ^ 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.
- ^ Martínez-Delgado, David; Karim, Noushin; Charles, Emily J E.; Boschin, Walter; Monelli, Matteo; Collins, Michelle L M.; Donatiello, Giuseppe; Alfaro, Emilio J. (2022). "Pisces VII: Discovery of a possible satellite of Messier 33 in the DESI legacy imaging surveys". Monthly Notices of the Royal Astronomical Society. 509 (1): 16–24. arXiv:2104.03859. Bibcode:2022MNRAS.509...16M. doi:10.1093/mnras/stab2797.
- ^ Collins, Michelle L M.; Karim, Noushin; Martinez-Delgado, David; Monelli, Matteo; Tollerud, Erik J.; Donatiello, Giuseppe; Navabi, Mahdieh; Charles, Emily; Boschin, Walter (2024). "Pisces VII/Triangulum III – M33's second dwarf satellite galaxy". Monthly Notices of the Royal Astronomical Society. 528 (2): 2614–2620. arXiv:2305.13966. Bibcode:2024MNRAS.528.2614C. doi:10.1093/mnras/stae199.