Astronomy:AK Leporis

From HandWiki
Short description: Star in the constellation Lepus
AK Leporis
AKLepLightCurve.png
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
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)9.57±0.13[6] 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
Mass0.8[2] M
Radius0.8[2] R
Luminosity0.3[2] L
Surface gravity (log g)4.66±0.01[7] cgs
Temperature4,869±61[7] K
Metallicity [Fe/H]0.01±0.06[7] dex
Rotational velocity (v sin i)2.8±1.8[6] km/s
Age0.9[8] Gyr
Other designations
BD−22 1210, GJ 216 B, HD 38392, HR 1982, LTT 2363, SAO 170757,[9] γ Leporis B[1]
Database references
SIMBADdata

AK Leporis 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 visual double 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.[10] Both Gamma Leporis and AK Leporis are members of the Ursa Major Moving Group of stars that share a common motion through space.[6]

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.[11]

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.[8]

References

  1. 1.0 1.1 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. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 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 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. 
  7. 7.0 7.1 7.2 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. 
  8. 8.0 8.1 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. 
  9. "V* AK Lep". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=V%2A+AK+Lep. 
  10. Kaler, James B., "Gamma Leporis", Stars (University of Illinois), http://stars.astro.illinois.edu/sow/gammalep.html, retrieved 2015-04-02. 
  11. 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.