6 Andromedae
6 Andromedae is an astrometric binary star[7] system in the northern constellation of Andromeda. The designation comes from the star catalogue of John Flamsteed, first published in 1712. Its apparent visual magnitude is 5.91,[2] which is just bright enough to be visible to the naked eye under good seeing conditions. Based upon an annual parallax shift of 34.1 mas as seen from Earth,[1] it is around 96 light years from the Sun. It is moving closer to the Sun with a radial velocity of −32.4 km/s.[2] The system has a relatively high proper motion, advancing across the celestial sphere at the rate of 0.272 arc seconds per annum.[8]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 23h 10m 27.23746s[1] |
| Declination | +43° 32′ 38.4336″[1] |
| Apparent magnitude (V) | 5.91[2] |
| Characteristics | |
| Spectral type | F5 V[3] |
| U−B color index | −0.05[3] |
| B−V color index | +0.450±0.004[2] |
| Astrometry | |
| Radial velocity (Rv) | −32.4±0.7[2] km/s |
| Proper motion (μ) | RA: +209.057[1] mas/yr Dec.: +138.052[1] mas/yr |
| Parallax (π) | 34.1008 ± 0.1650 mas[1] |
| Distance | 95.6 ± 0.5 ly (29.3 ± 0.1 pc) |
| Absolute magnitude (MV) | 3.71[2] |
| Orbit[3] | |
| Period (P) | 3,373±6 d |
| Periastron epoch (T) | 53116 ± 16 MJD |
| Argument of periastron (ω) (secondary) | 165.2±2.0° |
| Semi-amplitude (K1) (primary) | 8.75±0.09 km/s |
| Details | |
| Mass | 1.30[4] M☉ |
| Radius | 1.50+0.03 −0.06[1] R☉ |
| Luminosity | 3.090+0.018 −0.017[1] L☉ |
| Surface gravity (log g) | 4.09±0.14[4] cgs |
| Temperature | 6,425±218[4] K |
| Metallicity [Fe/H] | −0.19±0.03[2] dex |
| Rotational velocity (v sin i) | 18[5] km/s |
| Age | 2.91[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a single-lined spectroscopic binary with an orbital period of 9.2 years and an eccentricity of 0.3.[3] Some early observations of the star gave it a subgiant luminosity class and it was published in the Bright Star Catalogue as spectral class F5 IV. More modern measurements identify the visible component as an F-type main-sequence star with a stellar classification of F5 V.[3][9] The star is an estimated 2.9[4] billion years old with 1.3[4] times the mass of the Sun and 1.5[1] times the Sun's radius. It is radiating 3.1[1] times the Sun's luminosity from its photosphere at an effective temperature of around 6,425 K.[4] 6 Andromedae displays an infrared excess at a wavelength of 22 μm, which may indicate a circumstellar disk of warm dusty debris.[5]
The mass of the secondary component is roughly at or above that of the Sun. If it were a single, ordinary star, it should be readily visible as it would be just one magnitude fainter than the primary. The lack of conspicuous ultraviolet emission appears to rule out a white dwarf companion, so it may instead itself be a binary system consisting of two smaller stars having an orbital period between a week and a year.[3]
References edit
- ^ a b c d e f g h i j Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f g Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d e f Griffin, R. F. (April 2012), "Spectroscopic binary orbits from photoelectric radial velocities - Paper 223: HR 396, HR 7477, HR 7636, and 6 Andromedae", The Observatory, 132 (2): 76−97, Bibcode:2012Obs...132...76G.
- ^ a b c d e f g David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ a b Mizusawa, Trisha F.; et al. (November 2012), "Exploring the Effects of Stellar Rotation and Wind Clearing: Debris Disks around F Stars", The Astronomical Journal, 144 (5): 16, arXiv:1208.6248, Bibcode:2012AJ....144..135M, doi:10.1088/0004-6256/144/5/135, S2CID 41406330, 135.
- ^ "6 And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-01.
- ^ Frankowski, A.; et al. (March 2007), "Proper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data", Astronomy and Astrophysics, 464 (1): 377–392, arXiv:astro-ph/0612449, Bibcode:2007A&A...464..377F, doi:10.1051/0004-6361:20065526, S2CID 14010423.
- ^ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal, 129 (3): 1483–1522, arXiv:astro-ph/0412070, Bibcode:2005AJ....129.1483L, doi:10.1086/427854, S2CID 2603568.
- ^ Skiff, B. A. (2014). "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009-2016)". VizieR On-line Data Catalog: B/Mk. Originally Published in: Lowell Observatory (October 2014). 1. Bibcode:2014yCat....1.2023S.