The Boötes Dwarf Galaxy (Boo I dSph) is a galaxy discovered in 2006, which appears faint, with a luminosity of 100,000 L☉ and an absolute magnitude of –5.8. It lies about 197,000 light-years (60.4 kiloparsecs) away in the constellation Boötes. This dwarf spheroidal galaxy appears to be tidally disrupted[1] by the Milky Way Galaxy, which it orbits, and has two stellar tails that cross over to form a cross.[citation needed] Tidally disrupted galaxies usually only form one tail.[citation needed] The galaxy appears to be significantly elongated, with an ellipticity of ε = 0.68 ± 0.15.[3]
Like many of the ultrafaint dwarf spheroidals, the entire galaxy appears fainter than the Rigel system (absolute magnitude –7.84).[4] Even so, it is one of the more luminous UFDs.[5] It is metal-poor, like other UFDs, with a mean metallicity of −2.34.[5]
The stellar population of Boötes I is mostly very old stars. The two populations have essentially the same age, 13.4 billion and 13.3 billion years, respectively, with most of the stars being of the latter population.[6]
^ abcdefghBelokurov, V.; Zucker, D. B.; Evans, N. W.; Wilkinson, M. I.; et al. (2006). "A Faint New Milky Way Satellite in Bootes". The Astrophysical Journal. 647 (2): L111–L114. arXiv:astro-ph/0604355. Bibcode:2006ApJ...647L.111B. doi:10.1086/507324. S2CID 15348323.
^Longeard, Nicolas; Jablonka, Pascale; Arentsen, Anke; Thomas, Guillaume F.; Aguado, David S.; Carlberg, Raymond G.; Lucchesi, Romain; Malhan, Khyati; Martin, Nicolas; McConnachie, Alan W.; Navarro, Julio F.; Sánchez-Janssen, Rubén; Sestito, Federico; Starkenburg, Else; Yuan, Zhen (2022). "The Pristine dwarf galaxy survey – IV. Probing the outskirts of the dwarf galaxy Boötes I". Monthly Notices of the Royal Astronomical Society. 516 (2): 2348–2362. arXiv:2107.10849. Bibcode:2022MNRAS.516.2348L. doi:10.1093/mnras/stac1827.
^Shultz, M.; Wade, G. A.; Petit, V.; Grunhut, J.; Neiner, C.; Hanes, D.; MiMeS Collaboration (2014). "An observational evaluation of magnetic confinement in the winds of BA supergiants". Monthly Notices of the Royal Astronomical Society. 438 (2): 1114. arXiv:1311.5116. Bibcode:2014MNRAS.438.1114S. doi:10.1093/mnras/stt2260.
^ abJenkins, Sydney A.; Li, Ting S.; Pace, Andrew B.; Ji, Alexander P.; Koposov, Sergey E.; Mutlu-Pakdil, Burçin (2021). "Very Large Telescope Spectroscopy of Ultra-faint Dwarf Galaxies. I. Boötes I, Leo IV, and Leo V". The Astrophysical Journal. 920 (2): 92. arXiv:2101.00013. Bibcode:2021ApJ...920...92J. doi:10.3847/1538-4357/ac1353. S2CID 230433692.
^Brown, Thomas M.; Tumlinson, Jason; Geha, Marla; Simon, Joshua D.; Vargas, Luis C.; Vandenberg, Don A.; Kirby, Evan N.; Kalirai, Jason S.; Avila, Roberto J.; Gennaro, Mario; Ferguson, Henry C.; Muñoz, Ricardo R.; Guhathakurta, Puragra; Renzini, Alvio (2014). "The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization Era". The Astrophysical Journal. 796 (2): 91. arXiv:1410.0681. Bibcode:2014ApJ...796...91B. doi:10.1088/0004-637X/796/2/91. S2CID 10097277.
External links
The Universe within 500,000 light-years The Satellite Galaxies (Atlas of the Universe)
Two New Galaxies Orbiting the Milky Way (Ken Croswell) April 19, 2006
Strange satellite galaxies revealed around Milky Way Kimm Groshong (New Scientist) 17:00 24 April 2006
New Milky Way companions found: SDSS-II first to view two dim dwarf galaxies (SDSS) May 8, 2006
Astronomers Find Two New Milky Way Companions (SpaceDaily) May 10, 2006
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