Astronomy:Gliese 42

From HandWiki
Short description: Star in the constellation of Sculptor
Gliese 42
Observation data
Equinox J2000.0]] (ICRS)
Constellation Sculptor[1]
Right ascension  00h 53m 01.1349s[2]
Declination −30° 21′ 24.891″[2]
Apparent magnitude (V) +7.17[3]
Characteristics
Evolutionary stage main sequence[2]
Spectral type K2.5 V (k)[4]
B−V color index 0.936[5]
Astrometry
Radial velocity (Rv)−13.021±0.0064[6] km/s
Proper motion (μ) RA: +620.243[2] mas/yr
Dec.: +31.770[2] mas/yr
Parallax (π)71.7259 ± 0.0267[2] mas
Distance45.47 ± 0.02 ly
(13.942 ± 0.005 pc)
Absolute magnitude (MV)+6.39[1]
Details
Mass0.81[7] M☉
Radius0.74[7] R☉
Luminosity0.29[7] L☉
Surface gravity (log g)4.60[7] cgs
Temperature4,921[7] K
Metallicity [Fe/H]−0.21[4] dex
Rotational velocity (v sin i)1.8[8] km/s
Age6.67±4.74[9] Gyr
Other designations
BD−31°325, GJ 42, HD 5133, HIP 4148, SAO 192793, LTT 498, 2MASS J00530108-3021249[10]
Database references
SIMBADdata

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 +7.2. The annual parallax shift of 71.7 mas provides a distance estimate of 45 light years. It has a relatively high proper motion, advancing 0.62 arcseconds across the sky per annum,[11] and is moving closer to the Sun with a radial velocity of −13 km/s.[6]

The spectrum of the star matches a stellar classification of K2.5 V (k),[4] indicating it is an ordinary K-type main-sequence star that is generating energy through hydrogen fusion at its core. It is radiating 29% of the Sun's luminosity from its photosphere at an effective temperature of 4,921 K.[7] The star has 74% of the Sun's radius.[7]

Debris disk

An infrared excess has been detected around this star,[12] most likely indicating the presence of a circumstellar disk at a radius of 45.7 Astronomy:astronomical unit|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)[13] according to measurement by Herschel Space Observatory. Later that measurement was deemed questionable,[14] and fixed temperature of 62 K (−211.2 °C; −348.1 °F) was obtained in 2020.[15]

References

  1. ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A  XHIP record for this object at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 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.
  3. ↑ Koen, C.; Kilkenny, D.; Van Wyk, F.; Marang, F. (2010). "UBV(RI)C JHK observations of Hipparcos-selected nearby stars". Monthly Notices of the Royal Astronomical Society 403 (4): 1949. doi:10.1111/j.1365-2966.2009.16182.x. Bibcode: 2010MNRAS.403.1949K. 
  4. ↑ 4.0 4.1 4.2 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, doi:10.1086/504637, Bibcode: 2006AJ....132..161G. 
  5. ↑ van Leeuwen, F. (November 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. 
  6. ↑ 6.0 6.1 Soubiran, C. et al. (April 2013). "The catalogue of radial velocity standard stars for Gaia. I. Pre-launch release". Astronomy & Astrophysics 552: 11. doi:10.1051/0004-6361/201220927. A64. Bibcode: 2013A&A...552A..64S. 
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S. 
  8. ↑ Andretta, Vincenzo; Giampapa, Mark S.; Covino, Elvira; Reiners, Ansgar; Beeck, Benjamin (2017). "Estimates of Active Region Area Coverage through Simultaneous Measurements of the He I λλ 5876 and 10830 Lines". The Astrophysical Journal 839 (2): 97. doi:10.3847/1538-4357/aa6a14. Bibcode: 2017ApJ...839...97A. 
  9. ↑ Pace, G. (March 2013), "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram", Astronomy & Astrophysics 551: 4, doi:10.1051/0004-6361/201220364, L8, Bibcode: 2013A&A...551L...8P. 
  10. ↑ "HD 5133". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+5133. 
  11. ↑ 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, doi:10.1086/340115, Bibcode: 2002ApJS..141..187B. 
  12. ↑ Eiroa, C. et al. (July 2013). "DUst around NEarby Stars. The survey observational results". Astronomy & Astrophysics 555: A11. doi:10.1051/0004-6361/201321050. Bibcode: 2013A&A...555A..11E. 
  13. ↑ Cotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars", The Astrophysical Journal Supplement Series 225 (1): 24, doi:10.3847/0067-0049/225/1/15, 15, Bibcode: 2016ApJS..225...15C. 
  14. ↑ Gáspár, András; Rieke, George H. (2014). "The Herschel Cold Debris Disks: Confusion with the Extragalactic Background at 160 μm". The Astrophysical Journal 784 (1): 33. doi:10.1088/0004-637X/784/1/33. Bibcode: 2014ApJ...784...33G. 
  15. ↑ 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, doi:10.1093/mnras/staa1316 



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Gliese_42&oldid=3927348"