Gliese 445

Gliese 445 (Gl 445 or AC +79 3888) is an M-type main sequence star in the northern part of the constellation Camelopardalis.

Gliese 445

Image of AC +79 3888 (circled), also known as Gliese 445, located 17.1 light-years from Earth
Credit: Caltech/Palomar
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Camelopardalis
Right ascension 11h 47m 41.3885s[1]
Declination +78° 41′ 28.179″[1]
Apparent magnitude (V) 10.80[2]
Characteristics
Spectral type M4.0Ve[3]
B−V color index 1.572[2]
Astrometry
Radial velocity (Rv)−111.707[1] km/s
Proper motion (μ) RA: 748.111[1] mas/yr
Dec.: 480.804[1] mas/yr
Parallax (π)190.3251 ± 0.0194 mas[4]
Distance17.137 ± 0.002 ly
(5.2542 ± 0.0005 pc)
Absolute magnitude (MV)12.227[5]
Details
Mass0.14[6] M☉
Radius0.285[5] R☉
Luminosity0.008[7] L☉
Surface gravity (log g)4.72[7] cgs
Temperature3,507[1] K
Metallicity [Fe/H]−0.30[5] dex
Rotational velocity (v sin i)<2.5[8] km/s
Other designations
Gliese 445, Gl 445, G 254-29, AC+79 3888, HIP 57544, LFT 849, LHS 2459, LTT 13235, NLTT 28539, PLX 2722[9]
Database references
SIMBADdata
ARICNSdata
Gliese 445
Location of Gliese 445 in the constellation Camelopardalis

Location

It is currently 17.1 light-years from Earth and has an apparent magnitude of 10.8. It is visible from north of the Tropic of Cancer all night long, but not to the naked eye.[10] Because the star is a red dwarf with a mass only a quarter to a third of that of the Sun, scientists question the ability of this system to support life.[10] Gliese 445 is also a known X-ray source.[11]

The Voyager 1 probe will pass within 1.6 light-years of Gliese 445 in about 40,000 years.[12]

Solar encounter

While the Voyager probe moves through space towards a 1.6-light-year minimum distance from Gliese 445, the star is rapidly approaching the Sun. At the time the probe passes Gliese 445, the star will be about 1.059 parsecs (3.45 light-years) from the Sun,[13] but with less than half the brightness necessary to be seen with the naked eye.[10] At that time, Gliese 445 will be approximately tied with Ross 248 for being the closest star to the Sun (see List of nearest stars and brown dwarfs#Distant future and past encounters).

See also

References
  1. 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.
  2. Urban, S. E.; Zacharias, N.; Wycoff, Observatory G. L. U. S. Naval; Washington, 2004-2006 D. C. (2004). "VizieR Online Data Catalog: The UCAC2 Bright Star Supplement (Urban+, 2006)". VizieR On-line Data Catalog. Bibcode:2004yCat.1294....0U.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  3. Lépine, Sébastien; Hilton, Eric J.; Mann, Andrew W.; Wilde, Matthew; Rojas-Ayala, Bárbara; Cruz, Kelle L.; Gaidos, Eric (2013). "A Spectroscopic Catalog of the Brightest (J < 9) M Dwarfs in the Northern Sky". The Astronomical Journal. 145 (4): 102. arXiv:1206.5991. Bibcode:2013AJ....145..102L. doi:10.1088/0004-6256/145/4/102. S2CID 117144290.
  4. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  5. Houdebine, Éric R.; Mullan, D. J.; Doyle, J. G.; de la Vieuville, Geoffroy; Butler, C. J.; Paletou, F. (2019). "The Mass-Activity Relationships in M and K Dwarfs. I. Stellar Parameters of Our Sample of M and K Dwarfs". The Astronomical Journal. 158 (2): 56. arXiv:1905.07921. Bibcode:2019AJ....158...56H. doi:10.3847/1538-3881/ab23fe. S2CID 159041104.
  6. Gaidos, E.; Mann, A. W.; Lépine, S.; Buccino, A.; James, D.; Ansdell, M.; Petrucci, R.; Mauas, P.; Hilton, E. J. (2014). "Trumpeting M dwarfs with CONCH-SHELL: A catalogue of nearby cool host-stars for habitable exoplanets and life". Monthly Notices of the Royal Astronomical Society. 443 (3): 2561. arXiv:1406.7353. Bibcode:2014MNRAS.443.2561G. doi:10.1093/mnras/stu1313. S2CID 119234492.
  7. McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. S2CID 73594365.
  8. Stelzer, B.; Marino, A.; Micela, G.; López-Santiago, J.; Liefke, C. (2013). "The UV and X-ray activity of the M dwarfs within 10 pc of the Sun". Monthly Notices of the Royal Astronomical Society. 431 (3): 2063. arXiv:1302.1061. Bibcode:2013MNRAS.431.2063S. doi:10.1093/mnras/stt225. S2CID 119193975.
  9. "GJ 445". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved July 29, 2008.
  10. Mark Littmann (1 January 2004). Planets Beyond: Discovering the Outer Solar System. Courier Corporation. ISBN 978-0-486-43602-9.
  11. Schmitt JHMM; Fleming TA; Giampapa MS (September 1995). "The X-Ray View of the Low-Mass Stars in the Solar Neighborhood". Astrophys. J. 450 (9): 392–400. Bibcode:1995ApJ...450..392S. doi:10.1086/176149.
  12. "NASA – Voyager - Mission - Interstellar Mission". Jet Propulsion Laboratory. Archived from the original on 2009-10-15. Retrieved 2020-04-03.
  13. Bobylev, Vadim V. (March 2010). "Searching for Stars Closely Encountering with the Solar System". Astronomy Letters. 36 (3): 220–226. arXiv:1003.2160. Bibcode:2010AstL...36..220B. doi:10.1134/S1063773710030060. S2CID 118374161.
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