AK Leporis
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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| 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 mas[2] |
| Distance | 29.000 ± 0.004 ly (8.892 ± 0.001 pc) |
| Absolute magnitude (MV) | 6.31[3] |
| Details | |
| Mass | 0.8[2] M☉ |
| Radius | 0.8[2] R☉ |
| Luminosity | 0.3[2] L☉ |
| Surface gravity (log g) | 4.66±0.01[7] cgs |
| Temperature | 4,869±61[7] K |
| Metallicity [Fe/H] | 0.01±0.06[7] dex |
| Rotational velocity (v sin i) | 2.8±1.8[6] km/s |
| Age | 0.9[8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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 edit
- ^ a b 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, Bibcode:2000A&AS..145..275N, doi:10.1051/aas:2000243.
- ^ a b c d e f g h Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c 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, Bibcode:2004PASA...21..129N, doi:10.1071/AS04013.
- ^ a b c Lecavelier Des Etangs, A.; et al. (August 2005), "A photometric survey of stars with circumstellar material", Astronomy and Astrophysics, 439 (2): 571–574, Bibcode:2005A&A...439..571L, doi:10.1051/0004-6361:20042401.
- ^ a b Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ a b c 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, arXiv:1209.2591, Bibcode:2012MNRAS.427.2905B, doi:10.1111/j.1365-2966.2012.22132.x, S2CID 118617986.
- ^ a b c Prugniel, Ph.; et al. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics, 531: A165, arXiv:1104.4952, Bibcode:2011A&A...531A.165P, doi:10.1051/0004-6361/201116769, S2CID 54940439.
- ^ a b 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, arXiv:0909.0058, Bibcode:2009ApJ...705...89L, doi:10.1088/0004-637X/705/1/89, S2CID 1272803.
- ^ "V* AK Lep", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2015-04-02.
- ^ Kaler, James B., "Gamma Leporis", Stars, University of Illinois, retrieved 2015-04-02.
- ^ 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, arXiv:0910.3938, Bibcode:2010AJ....139...96L, doi:10.1088/0004-6256/139/1/96, S2CID 118537554.