Astronomy:2 Equulei
2 Equulei is a double star system in the constellation of Equuleus.
The primary component of the 2 Equulei pair is an F-type star. As of 2015, the secondary had an angular separation of 2.90 arc seconds along a position angle of 213° from the primary.[2] They form a common proper motion pair, two stars at approximately the same distance and moving in the same direction.[4] Gaia DR3 gives them parallaxes of 8.8125±0.2471 mas and 8.5577±0.0298 mas respectively, although they are flagged as potentially unreliable.[1][3] These parallaxes correspond to a distance of around 380 ly, in contrast to the Hipparcos distance of 260±20 ly for the two stars as a pair.[9]
2 Equulei has been referred to in some sources as λ (Lambda) Equulei, although it was not given that designation by Bayer.[10]
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 4.0 4.1 Abt, Helmut A. (2008). "Visual Multiples. IX. MK Spectral Types". The Astrophysical Journal Supplement Series 176 (1): 216–217. doi:10.1086/525529. Bibcode: 2008ApJS..176..216A.
- ↑ Adams, Walter S.; Joy, Alfred H.; Humason, Milton L.; Brayton, Ada Margaret (1935). "The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars". The Astrophysical Journal 81: 187. doi:10.1086/143628. Bibcode: 1935ApJ....81..187A.
- ↑ 6.0 6.1 6.2 Casagrande, L. et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics 530 (A138): 21, doi:10.1051/0004-6361/201016276, Bibcode: 2011A&A...530A.138C.
- ↑ Holmberg, J. et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics 501 (3): 941–947, doi:10.1051/0004-6361/200811191, Bibcode: 2009A&A...501..941H.
- ↑ "2 Equ -- Double or multiple star", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=2+Equ, retrieved 2017-02-17.
- ↑ van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy 18 (3): 215. doi:10.1177/002182868701800305. Bibcode: 1987JHA....18..209W.
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