Andromeda XXXVI
| Andromeda XXXVI | |
|---|---|
.png) Image of Andromeda XXXVI from Giuseppe Donatiello | |
| Observation data (J2000 epoch) | |
| Constellation | Andromeda |
| Right ascension | 01h 16m 40.3s[1] |
| Declination | +47° 39′ 22″[1] |
| Distance | 776 kpc (2.53 Mly)[2] |
| Absolute magnitude (V) | −5.9±0.1[2] |
| Characteristics | |
| Type | dSph |
| Half-light radius (physical) | 208+98 −62 ly (64+30 −19 pc)[2] |
| Half-light radius (apparent) | 0.284+0.132 −0.084[2] |
| Notable features | satellite galaxy of Andromeda Galaxy, one of the faintest discovered to date |
| Other designations | |
| And XXXVI, A36[2] | |
Andromeda XXXVI (And XXXVI) is an ultra-faint dwarf spheroidal galaxy located at a distance of 776 kiloparsecs, or 2.53 million light-years, from the Sun in the constellation of Andromeda, within the Local Group. It is one of the faintest ultra-faint dwarf galaxies of M31 discovered to date.[2][3]
Discovery
[edit]Andromeda XXXVI was first identified by astrophotographer and amateur astronomer Giuseppe Donatiello during a visual inspection of archival public data from the Pan-Andromeda Archaeological Survey (PAndAS), conducted with the Canada-France-Hawaii Telescope, and subsequently confirmed through observations using the Gran Telescopio Canarias. The results were published in the scientific journal Astronomy & Astrophysics on June 25, 2026.[2][3]
Physical characteristics
[edit]Andromeda XXXVI is classified as an ultra-faint dwarf spheroidal galaxy with an effective half-light radius of 208+98
−62 light-years (64+30
−19 parsecs). The galaxy’s ellipticity is extremely low, approximately 0.015+0.032
−0.012, which gives its projection on the sky a nearly perfect spherical shape.[2][3] The position angle of the major axis is θ = 78.6+29.7
−28.5.[2] The absolute magnitude of the galaxy in the visible range is estimated at MV = −5.9±0.1.[2][3]
Its projected distance from the center of the Andromeda Galaxy is about 388,000 light-years.[2][3] Given that the virial radius of M31’s gravitational influence is estimated at 850,000 light-years, Andromeda XXXVI lies deep within its halo and is a gravitationally bound satellite.[2][3]
Color-magnitude diagram modeling indicates that the system's stellar population is approximately 12.5 billion years old, with a metallicity [Fe/H] = -2.5.[2][3] Such a low abundance of elements heavier than helium suggests that the galaxy formed in the early Universe, underwent only a brief initial burst of star formation, and is completely devoid of the modern interstellar gas required to trigger the formation of new stars.[2][3]
See also
[edit]References
[edit]- 1 2 "NAME Andromeda XXXVI". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2 April 2011.
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Sakowska Dr, Joanna; Martínez-Delgado, David; L. M. Collins, Michelle; Monelli, Matteo; Donatiello, Giuseppe; Doliva-Dolinsky, Amandine; M. E. Santos-Santos, Isabel (2026). "Andromeda XXXVI: discovery of a new ultra-faint dwarf galaxy towards M31". Astronomy & Astrophysics. 710 (A342): 8. arXiv:2603.28492. Bibcode:2026A&A...710A.342S. doi:10.1051/0004-6361/202660151.
- 1 2 3 4 5 6 7 8 Tomasz Nowakowski (April 7, 2026). Baum, Stephanie; Egan, Robert (eds.). "Astronomers discover Andromeda XXXVI, an ultra-faint dwarf satellite galaxy". Phys.org. Retrieved 2026-03-30.
| Location | Andromeda Galaxy → Andromeda subgroup → Local Group → Local Sheet → Local Volume → Virgo Supercluster → Laniakea Supercluster → Pisces–Cetus Supercluster Complex → Local Hole → Observable universe → Universe Each → may be read as "within" or "part of". |  |
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*It is uncertain whether these are companion galaxies of the Andromeda Galaxy | |
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