Astronomy:Omega Andromedae
Observation data Equinox J2000.0]] (ICRS) | |
---|---|
Constellation | Andromeda |
Right ascension | 01h 27m 39.38072s[1] |
Declination | +45° 24′ 24.0651″[1] |
Apparent magnitude (V) | +4.83[2][3] |
Characteristics | |
Spectral type | F5 IVe[4] or F3 V + F5 V[5] |
U−B color index | +0.00[3] |
B−V color index | +0.42[3] |
Astrometry | |
Radial velocity (Rv) | +14.7[2] km/s |
Proper motion (μ) | RA: 357.564(127)[1] mas/yr Dec.: −110.039(118)[1] mas/yr |
Parallax (π) | 34.7332 ± 0.1341[1] mas |
Distance | 93.9 ± 0.4 ly (28.8 ± 0.1 pc) |
Absolute magnitude (MV) | +2.57[2] |
Details | |
ω And A | |
Mass | 0.963±0.049[5] M☉ |
Radius | 2.2[6] R☉ |
Luminosity | 7.1[7] L☉ |
Temperature | 6,628[7] K |
Metallicity [Fe/H] | −0.16[2] dex |
Rotational velocity (v sin i) | 57.1[8] km/s |
Age | 2.1[2] Gyr |
ω And B | |
Mass | 0.860±0.051[5] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
Omega Andromedae (ω And, ω Andromedae) is the Bayer designation for a slowly co-rotating[failed verification] binary star system[9] in the northern constellation of Andromeda. Parallax measurements made during the Gaia mission make this system to be approximately 93.9 light-years (28.8 parsecs) from Earth. Its apparent visual magnitude is +4.83,[2] which makes it bright enough to be seen with the naked eye.
The primary component has a stellar classification of F5 IVe.[4] The IV luminosity class indicates that it is probably a subgiant star that is in the process of evolving away from the main sequence as the supply of hydrogen at its core depletes. However, Abt (1985) gives a classification of F3 V, suggesting it is an F-type main-sequence star.[5] The measured angular diameter of the primary star is 0.70 ± 0.03 mas.[10] At the system's estimated distance this yields a size of about 2.2 times that of the Sun.[6] It is emitting about seven times solar luminosity from its outer atmosphere at an effective temperature of 6,628 K.[7] This heat gives it the yellow-white-hued glow of an F-type star.[11]
In 2008, the companion star was resolved using adaptive optics at the Lick Observatory. Later observations showed the magnitude difference between the two stars is 3.65 ± 0.03 and they are separated by 0.669 arcsecond.[9] Abt (1985) lists the class as F5 V.[5]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Nordström, B. et al. (May 2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14 000 F and G dwarfs", Astronomy and Astrophysics 418: 989–1019, doi:10.1051/0004-6361:20035959, Bibcode: 2004A&A...418..989N.
- ↑ 3.0 3.1 3.2 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
- ↑ 4.0 4.1 4.2 "ome And". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ome+And.
- ↑ 5.0 5.1 5.2 5.3 5.4 Farrington, C. D. et al. (September 2014), "Separated Fringe Packet Observations with the CHARA Array. II. ω Andromeda, HD 178911, and ξ Cephei", The Astronomical Journal 148 (3): 8, doi:10.1088/0004-6256/148/3/48, 48, Bibcode: 2014AJ....148...48F.
- ↑ 6.0 6.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41. The radius (R*) is given by:
- [math]\displaystyle{ \begin{align} 2\cdot R_* & = \frac{(28.6\cdot 0.70\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 4.31\cdot R_{\bigodot} \end{align} }[/math]
- ↑ 7.0 7.1 7.2 do Nascimento, J. D. Jr. et al. (July 2003), "On the link between rotation, chromospheric activity and Li abundance in subgiant stars", Astronomy and Astrophysics 405 (2): 723–731, doi:10.1051/0004-6361:20030633, Bibcode: 2003A&A...405..723D.
- ↑ Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo", Astronomy and Astrophysics 493 (3): 1099–1107, doi:10.1051/0004-6361:200810377, Bibcode: 2009A&A...493.1099S, http://goedoc.uni-goettingen.de/goescholar/bitstream/handle/1/9690/aa10377-08.pdf?sequence=2[yes|permanent dead link|dead link}}]
- ↑ 9.0 9.1 Gladysz, Szymon; Christou, Julian C. (June 2009), "Reference-Less Detection, Astrometry, and Photometry of Faint Companions with Adaptive Optics", The Astrophysical Journal 698 (1): 28–42, doi:10.1088/0004-637X/698/1/28, Bibcode: 2009ApJ...698...28G.
- ↑ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode: 2005A&A...431..773R
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16.
External links
![]() | Original source: https://en.wikipedia.org/wiki/Omega Andromedae.
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