AK Leporis
Star in the constellation Lepus
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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]
| 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 | |
| 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 mas[2] |
| Distance | 29.000 ± 0.004 ly (8.892 ± 0.001 pc) |
| Absolute magnitude (MV) | 6.31[3] |
| Details | |
| Mass | 0.800+0.040 −0.048[2] M☉ |
| Radius | 0.793±0.017[2] R☉ |
| Luminosity | 0.300±0.005[2] L☉ |
| Surface gravity (log g) | 4.66±0.01[6] cgs |
| Temperature | 4,869±61[6] K |
| Metallicity [Fe/H] | 0.01±0.06[6] dex |
| Rotation | 17.3 days[7] |
| Rotational velocity (v sin i) | 2.8±1.8[8] km/s |
| Age | 0.9[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 | |
| 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.[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]