Astronomy:AK Leporis

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Short description: Star in the constellation Lepus
AK Leporis
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A visual band light curve for AK Leporis, adapted from Nitschelm et al. (2000)[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Lepus
Right ascension  05h 44m 26.537s[2]
Declination −22° 25′ 18.61″[2]
Apparent magnitude (V) 6.141[3]
Characteristics
Evolutionary stage main sequence[2]
Spectral type K2V[4]
U−B color index +0.74[5]
B−V color index +0.96[5]
Variable type BY Draconis[4]
Astrometry
Radial velocity (Rv)−9.80±0.12[2] km/s
Proper motion (μ) RA: −304.905[2] mas/yr
Dec.: −352.606[2] mas/yr
Parallax (π)112.4661 ± 0.0151[2] mas
Distance29.000 ± 0.004 ly
(8.892 ± 0.001 pc)
Absolute magnitude (MV)6.31[3]
Details
Mass0.800+0.040
−0.048
[2] M
Radius0.793±0.017[2] R
Luminosity0.300±0.005[2] L
Surface gravity (log g)4.66±0.01[6] cgs
Temperature4,869±61[6] K
Metallicity [Fe/H]0.01±0.06[6] dex
Rotation17.3 days[7]
Rotational velocity (v sin i)2.8±1.8[8] km/s
Age0.9[9] Gyr
Other designations
γ Lep B, AK Lep, BD−22 1210, GJ 216 B, HD 38392, HR 1982, SAO 170757, LTT 2363[10]
Database references
SIMBADdata

AK Leporis, also known as Gamma Leporis B, is a variable star in the southern constellation of Lepus the hare. It has an apparent visual magnitude of 6.141,[3] so, according to the Bortle scale, it is faintly visible from rural skies at night. This star forms a wide binary star system with Gamma Leporis—the two have an angular separation of 97, making them difficult to separate with the naked eye even under the best conditions.[11][12] Both Gamma Leporis and AK Leporis are members of the Ursa Major Moving Group of stars that share a common motion through space.[8]

This is a BY Draconis variable star that undergoes slight brightness variations due to stellar activity. Differential rotation causes changes to the periodicity of the variation depending on the latitude of the activity.[4] X-ray emission has been detected from AK Leporis, and it is located at or near a radio source.[13]

Infrared observation of this star shows a large excess at a wavelength of 24 μm. This may be explained by the proximity of Gamma Leporis to the line of sight, or there may be a red dwarf companion or a dust disc. There is no excess observed at 70 μm.[9]

See also

References

  1. Nitschelm, C.; des Etangs, A. Lecavelier; Vidal-Madjar, A.; Ferlet, R.; Olsen, E. H.; Dennefeld, M. (August 2000), "A three-year Strömgren photometric survey of suspected β Pictoris-like stars", Astronomy and Astrophysics Supplement Series 145 (2): 275–281, doi:10.1051/aas:2000243, Bibcode2000A&AS..145..275N. 
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 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. 3.0 3.1 3.2 Nordström, Andersen et al. (2004), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ~14000 F and G dwarfs", Publications of the Astronomical Society of Australia 21 (2): 129–133, doi:10.1071/AS04013, Bibcode2004PASA...21..129N. 
  4. 4.0 4.1 4.2 Lecavelier Des Etangs, A. et al. (August 2005), "A photometric survey of stars with circumstellar material", Astronomy and Astrophysics 439 (2): 571–574, doi:10.1051/0004-6361:20042401, Bibcode2005A&A...439..571L. 
  5. 5.0 5.1 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode1986EgUBV........0M. 
  6. 6.0 6.1 6.2 Prugniel, Ph. et al. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics 531: A165, doi:10.1051/0004-6361/201116769, Bibcode2011A&A...531A.165P. 
  7. Cincunegui, C.; Díaz, R. F.; Mauas, P. J. D. (2007). "Hα and the Ca II H and K lines as activity proxies for late-type stars". Astronomy and Astrophysics 469 (1): 309. doi:10.1051/0004-6361:20066503. Bibcode2007A&A...469..309C. 
  8. 8.0 8.1 Biazzo, K. et al. (December 2012), "Elemental abundances of low-mass stars in nearby young associations: AB Doradus, Carina Near and Ursa Major", Monthly Notices of the Royal Astronomical Society 427 (4): 2905–2916, doi:10.1111/j.1365-2966.2012.22132.x, Bibcode2012MNRAS.427.2905B. 
  9. 9.0 9.1 Lawler, S. M. et al. (November 2009), "Explorations Beyond the Snow Line: Spitzer/IRS Spectra of Debris Disks Around Solar-type Stars", The Astrophysical Journal 705 (1): 89–111, doi:10.1088/0004-637X/705/1/89, Bibcode2009ApJ...705...89L. 
  10. "V* AK Lep". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=V%2A+AK+Lep. 
  11. Kaler, James B., "Gamma Leporis", Stars (University of Illinois), http://stars.astro.illinois.edu/sow/gammalep.html, retrieved 2015-04-02. 
  12. Reylé, Céline; Jardine, Kevin; Fouqué, Pascal; Caballero, Jose A.; Smart, Richard L.; Sozzetti, Alessandro (30 April 2021), "The 10 parsec sample in the Gaia era", Astronomy & Astrophysics 650: A201, doi:10.1051/0004-6361/202140985, Bibcode2021A&A...650A.201R.  Data available at https://gruze.org/10pc/
  13. Lazio, T. Joseph W. et al. (January 2010), "A Blind Search for Magnetospheric Emissions from Planetary Companions to Nearby Solar-Type Stars", The Astronomical Journal 139 (1): 96–101, doi:10.1088/0004-6256/139/1/96, Bibcode2010AJ....139...96L.