From Wikipedia, the free encyclopedia
Gliese 42
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]
Distance45.59 ± 0.04  ly
(13.98 ± 0.01  pc)
Absolute magnitude (MV)+6.39 [5]
Details
Radius0.660 [6]  R
Luminosity0.29 [5]  L
Surface gravity (log g)4.55 [2]  cgs
Temperature4,822 [2]  K
Metallicity [Fe/H]−0.21 [2]  dex
Rotational velocity (v sin i)1.8 [7] km/s
Age6.67±4.74 [8]  Gyr
Other designations
BD−31° 325, Gaia DR2 5031808453624044800, GJ 42, HD 5133, HIP 4148, SAO 192793, LTT 498, 2MASS J00530108-3021249 [9]
Database references
SIMBAD data

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]

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

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

  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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
  8. ^ 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.
  9. ^ "HD 5133". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-01.
  10. ^ 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.
  11. ^ 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.
  12. ^ "THE HERSCHEL COLD DEBRIS DISKS: CONFUSION WITH THE EXTRAGALACTIC BACKGROUND AT 160 μm". Archived from the original on 2022-08-06. Retrieved 2020-10-16.
  13. ^ 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

From Wikipedia, the free encyclopedia
Gliese 42
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]
Distance45.59 ± 0.04  ly
(13.98 ± 0.01  pc)
Absolute magnitude (MV)+6.39 [5]
Details
Radius0.660 [6]  R
Luminosity0.29 [5]  L
Surface gravity (log g)4.55 [2]  cgs
Temperature4,822 [2]  K
Metallicity [Fe/H]−0.21 [2]  dex
Rotational velocity (v sin i)1.8 [7] km/s
Age6.67±4.74 [8]  Gyr
Other designations
BD−31° 325, Gaia DR2 5031808453624044800, GJ 42, HD 5133, HIP 4148, SAO 192793, LTT 498, 2MASS J00530108-3021249 [9]
Database references
SIMBAD data

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]

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

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

  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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
  8. ^ 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.
  9. ^ "HD 5133". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-01.
  10. ^ 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.
  11. ^ 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.
  12. ^ "THE HERSCHEL COLD DEBRIS DISKS: CONFUSION WITH THE EXTRAGALACTIC BACKGROUND AT 160 μm". Archived from the original on 2022-08-06. Retrieved 2020-10-16.
  13. ^ 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


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