Astronomy:42 Persei
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Perseus |
| Right ascension | 03h 49m 32.68952s[1] |
| Declination | 33° 05′ 28.9603″[1] |
| Apparent magnitude (V) | 5.05 - 5.18[2] |
| Characteristics | |
| Spectral type | A3V[3] + MV[4] |
| U−B color index | +0.11[5] |
| B−V color index | +0.07[5] |
| Variable type | Ellipsoidal[4] |
| Astrometry | |
| Radial velocity (Rv) | −12.40[6] km/s |
| Proper motion (μ) | RA: −28.483[7] mas/yr Dec.: +6.260[7] mas/yr |
| Parallax (π) | 10.8041 ± 0.1504[7] mas |
| Distance | 302 ± 4 ly (93 ± 1 pc) |
| Absolute magnitude (MV) | 0.57[8] |
| Orbit[4] | |
| Period (P) | 1.7653511 ± 0.000002 d |
| Semi-major axis (a) | 8.207 R☉ |
| Eccentricity (e) | 0.056 |
| Inclination (i) | 65.3° |
| Argument of periastron (ω) (secondary) | 257° |
| Semi-amplitude (K1) (primary) | 34.34 km/s |
| Details | |
| 42 Per A | |
| Mass | 2.0[4] M☉ |
| Radius | 3.48[4] R☉ |
| Luminosity | 59[9] L☉ |
| Surface gravity (log g) | 3.78[10] cgs |
| Temperature | 8,892[9] K |
| Metallicity [Fe/H] | 0.00[11] dex |
| Rotational velocity (v sin i) | 91[9] km/s |
| 42 Per B | |
| Mass | 0.38[4] M☉ |
| Temperature | 3,500[4] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
42 Persei is a binary star system in the northern constellation of Perseus. It has the Bayer designation n Persei, while 42 Persei is the Flamsteed designation. The system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.11.[5] It is located around 93 parsecs (302 ly) distant from the Sun,[1] but is drifting closer with a radial velocity of −12.4 km/s.[6]
42 Persei is a single-lined spectroscopic binary with an orbital period of 1.77 days and an eccentricity of just 0.056.[4] It is a variable star, ranging in brightness from magnitude 5.05 to 5.18, and was assumed at discovery to be a close, but detached, eclipsing variable.[2] Closer studies of the light variations and the orbit have shown that the main brightness changes are due to rotation of the distorted primary star, although it is predicted from the likely inclination of the orbit that shallow eclipses could also occur.[4]
The visible component is an A-type main-sequence star with a stellar classification of A3V;[3] a star that is fusing its core hydrogen. It has been reported as a mild Am star,[13] but this is considered questionable.[14] The star has twice[4] the mass of the Sun and 3.5[4] times the Sun's radius. It has a high rate of spin, showing a projected rotational velocity of 91 km/s.[9] The star is radiating 59[9] times the luminosity of the Sun from its photosphere at an effective temperature of 8,892 K.[9] The unseen companion star is likely to be a dim red dwarf with 38% of the Sun's mass.[4]
In Chinese astronomy, 42 Persei is called 天讒, Pinyin: Tiānchán, meaning Celestial Slander, because this star is marking itself and stand alone in Celestial Slander asterism, Hairy Head mansion (see : Chinese constellation).[15]
References
- ↑ 1.0 1.1 1.2 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. Vizier catalog entry
- ↑ 2.0 2.1 Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1. Bibcode: 2009yCat....102025S.
- ↑ 3.0 3.1 Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H 5050. Bibcode: 1995yCat.5050....0H.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 Martin, Brian E. (1990). "The ellipsoidal variable 42 Persei - Observations and model". Astronomical Society of the Pacific 102: 1153–1160. doi:10.1086/132746. Bibcode: 1990PASP..102.1153M.
- ↑ 5.0 5.1 5.2 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode: 2002yCat.2237....0D.
- ↑ 6.0 6.1 Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G. et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics 424 (2): 727–732. doi:10.1051/0004-6361:20041213. Bibcode: 2004A&A...424..727P.
- ↑ 7.0 7.1 7.2 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. Vizier catalog entry
- ↑ 9.0 9.1 9.2 9.3 9.4 9.5 Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode: 2012A&A...537A.120Z.
- ↑ 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. doi:10.1088/0004-637X/804/2/146. Bibcode: 2015ApJ...804..146D. Vizier catalog entry
- ↑ Gontcharov, G. A. (2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters 38 (12): 771–782. doi:10.1134/S1063773712120031. Bibcode: 2012AstL...38..771G.
- ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html.
- ↑ Margoni, R.; Munari, U.; Stagni, R. (1992). "Spectroscopic orbits of AM stars. I. Seven field stars". Astronomy and Astrophysics Supplement Series 93: 545. Bibcode: 1992A&AS...93..545M.
- ↑ Renson, P.; Manfroid, J. (2009). "Catalogue of Ap, HGMN and Am stars". Astronomy and Astrophysics 498 (3): 961. doi:10.1051/0004-6361/200810788. Bibcode: 2009A&A...498..961R.
- ↑ Ian Ridpath's Startales - Perseus
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