HD 154577
Star in the constellation Ara
From Wikipedia, the free encyclopedia
HD 154577 (Gliese 656) is a K-type main-sequence star in the southern constellation of Ara. It is a high proper motion star and, based upon an annual parallax shift of 73.41 mas,[2] is located about 44 light years from the Sun. The star is too faint to be readily visible to the naked eye, having an apparent visual magnitude of 7.4.[3] It is moving away from the Sun with a radial velocity of +9 km/s.[6]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Ara[1] |
| Right ascension | 17h 10m 10.35091s[2] |
| Declination | −60° 43′ 43.5757″[2] |
| Apparent magnitude (V) | 7.385[3] |
| Characteristics | |
| Spectral type | K2.5Vk:[4] |
| U−B color index | +0.53[5] |
| B−V color index | +0.89[5] |
| Astrometry | |
| Radial velocity (Rv) | +8.8[6] km/s |
| Proper motion (μ) | RA: 70.96[2] mas/yr Dec.: 589.86[2] mas/yr |
| Parallax (π) | 73.41±0.70 mas[2] |
| Distance | 44.4 ± 0.4 ly (13.6 ± 0.1 pc) |
| Absolute magnitude (MV) | 6.71[3] |
| Details | |
| Mass | 0.68[7] M☉ |
| Radius | 0.68[8] R☉ |
| Luminosity | 0.24[9] L☉ |
| Surface gravity (log g) | 4.70[4] cgs |
| Temperature | 4,850[4] K |
| Metallicity [Fe/H] | −0.70[10] dex |
| Rotational velocity (v sin i) | 0.2[11] km/s |
| Age | 3.2[12] Gyr |
| Other designations | |
| CD−60 6576, GCTP, GJ 656, HD 154577, HIP 83990, LHS 3268, LTT 6833, SAO 253819[13] | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
This star has only 68% of the Sun's mass and radius, an effective temperature of 4,850 K and a stellar classification of K2.5Vk:,[4] which indicates it is a K-type main sequence star. (The 'k' suffix indicates there are interstellar absorption features in the spectra, while ':' means there is some uncertainty about the classification.) It is about 3.2[12] billion years old and appears to be spinning slowly with a projected rotational velocity of 0.2 km/s.[11] The star is radiating 24%[9] of the Sun's luminosity from its photosphere at an effective temperature of 4,850 K.[4]
As of 2005, this star is not known to host any planets.[7] No excess of infrared radiation has been detected of the type that would indicate the presence of an orbiting debris disk.[12]