Gliese 42
Gliese 42 is a star in the southern constellation of Sculptor. It is too faint to be seen with the naked eye, having an apparent visual magnitude of +7.3.[1] The annual parallax shift of 70.56 mas provides a distance estimate of 46 light years. It has a relatively high proper motion, advancing 0.62[10] arcseconds across the sky per annum, and is moving closer to the Sun with a radial velocity of −13 km/s.[3]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sculptor |
| Right ascension | 00h 53m 00.71555s[1] |
| Declination | −30° 21′ 25.1677″[1] |
| Apparent magnitude (V) | +7.3029[1] |
| Characteristics | |
| Spectral type | K2.5 V (k)[2] |
| B−V color index | 0.936[1] |
| Astrometry | |
| Radial velocity (Rv) | −13.021±0.0064[3] km/s |
| Proper motion (μ) | RA: +620.35[1] mas/yr Dec.: +30.26[1] mas/yr |
| Parallax (π) | 71.5472 ± 0.0573 mas[4] |
| Distance | 45.59 ± 0.04 ly (13.98 ± 0.01 pc) |
| Absolute magnitude (MV) | +6.39[5] |
| Details | |
| Radius | 0.660[6] R☉ |
| Luminosity | 0.29[5] L☉ |
| Surface gravity (log g) | 4.55[2] cgs |
| Temperature | 4,822[2] K |
| Metallicity [Fe/H] | −0.21[2] dex |
| Rotational velocity (v sin i) | 1.8[7] km/s |
| Age | 6.67±4.74[8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The spectrum of the star matches a stellar classification of K2.5 V (k),[2] indicating it is an ordinary K-type main-sequence star that is generating energy through hydrogen fusion at its core. It is radiating 29%[5] of the Sun's luminosity from its photosphere at an effective temperature of 4,822 K.[2] The star has 66%[6] of the Sun's radius.
Debris disk edit
An infrared excess has been detected around this star,[11] most likely indicating the presence of a circumstellar disk at a radius of 45.7 astronomical units (6.84×109 km; 4.25×109 mi). The temperature of this dust was initially estimated as 30 K (−243.2 °C; −405.7 °F)[6] according to measurement by Herschel Space Observatory. Later that measurement was deemed questionable,[12] and fixed temperature of 62 K (−211.2 °C; −348.1 °F) was obtained in 2020.[13]
References edit
- ^ a b c d e f g van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d e f Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
- ^ a b Soubiran, C.; et al. (April 2013). "The catalogue of radial velocity standard stars for Gaia. I. Pre-launch release". Astronomy & Astrophysics. 552: 11. arXiv:1302.1905. Bibcode:2013A&A...552A..64S. doi:10.1051/0004-6361/201220927. S2CID 56094559. A64.
- ^ 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 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 Cotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars", The Astrophysical Journal Supplement Series, 225 (1): 24, arXiv:1606.01134, Bibcode:2016ApJS..225...15C, doi:10.3847/0067-0049/225/1/15, S2CID 118438871, 15.
- ^ Andretta, Vincenzo; Giampapa, Mark S.; Covino, Elvira; Reiners, Ansgar; Beeck, Benjamin (2017), "ESTIMATES OF ACTIVE REGION AREA COVERAGE THROUGH SIMULTANEOUS MEASUREMENTS OF HE I λλ 5876 AND 10830 LINES", The Astrophysical Journal, 839 (2): 97, arXiv:1703.10060, Bibcode:2017ApJ...839...97A, doi:10.3847/1538-4357/aa6a14, S2CID 119201107
- ^ Pace, G. (March 2013), "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram", Astronomy & Astrophysics, 551: 4, arXiv:1301.5651, Bibcode:2013A&A...551L...8P, doi:10.1051/0004-6361/201220364, S2CID 56420519, L8.
- ^ "HD 5133". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-01.
- ^ Bakos, Gáspár Á.; et al. (July 2002), "Revised Coordinates and Proper Motions of the Stars in the Luyten Half-Second Catalog", The Astrophysical Journal Supplement Series, 141 (1): 187–193, arXiv:astro-ph/0202164, Bibcode:2002ApJS..141..187B, doi:10.1086/340115, S2CID 36667868.
- ^ Eiroa, C.; et al. (July 2013). "DUst around NEarby Stars. The survey observational results". Astronomy & Astrophysics. 555: A11. arXiv:1305.0155. Bibcode:2013A&A...555A..11E. doi:10.1051/0004-6361/201321050. S2CID 377244.
- ^ THE HERSCHEL COLD DEBRIS DISKS: CONFUSION WITH THE EXTRAGALACTIC BACKGROUND AT 160 μm
- ^ Su, Kate Y L.; Kennedy, Grant M.; Yelverton, Ben (2020), "No significant correlation between radial velocity planet presence and debris disc properties", Monthly Notices of the Royal Astronomical Society, 495 (2): 1943–1957, arXiv:2005.03573, doi:10.1093/mnras/staa1316, S2CID 218538179
External links edit
- University of Heidelberg, The. . Archived from the original on 28 September 2012. Retrieved 8 May 2012.
- University of Strasbourg, The. "SIMBAD star database". Retrieved 8 May 2012.
- University of Hamburg, The. "NEXXUS 2 - The database for Nearby X-ray and extreme UV emitting Stars". Retrieved 8 May 2012.
- Sol Stations, The. "K stars within 100 light-years". Retrieved 8 May 2012.