Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Sculptor |
Right ascension | 00h 53m 00.71555s[1] |
Declination | −30° 21′ 25.1677″[1] |
Apparent magnitude (V) | +7.3029[1] |
Characteristics | |
Spectral type | K2.5 V (k)[2] |
B−V color index | 0.936[1] |
Astrometry | |
Radial velocity (Rv) | −13.021±0.0064[3] km/s |
Proper motion (μ) | RA: +620.35[1] mas/yr Dec.: +30.26[1] mas/yr |
Parallax (π) | 71.5472 ± 0.0573 mas[4] |
Distance | 45.59 ± 0.04 ly (13.98 ± 0.01 pc) |
Absolute magnitude (MV) | +6.39[5] |
Details | |
Radius | 0.660[6] R☉ |
Luminosity | 0.29[5] L☉ |
Surface gravity (log g) | 4.55[2] cgs |
Temperature | 4,822[2] K |
Metallicity [Fe/H] | −0.21[2] dex |
Rotational velocity (v sin i) | 1.8[7] km/s |
Age | 6.67±4.74[8] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Gliese 42 is a star in the southern constellation of Sculptor. It is too faint to be seen with the naked eye, having an apparent visual magnitude of +7.3.[1] The annual parallax shift of 70.56 mas provides a distance estimate of 46 light years. It has a relatively high proper motion, advancing 0.62[10] arcseconds across the sky per annum, and is moving closer to the Sun with a radial velocity of −13 km/s.[3]
The spectrum of the star matches a stellar classification of K2.5 V (k),[2] indicating it is an ordinary K-type main-sequence star that is generating energy through hydrogen fusion at its core. It is radiating 29%[5] of the Sun's luminosity from its photosphere at an effective temperature of 4,822 K.[2] The star has 66%[6] of the Sun's radius.
An infrared excess has been detected around this star,[11] most likely indicating the presence of a circumstellar disk at a radius of 45.7 astronomical units (6.84×109 km; 4.25×109 mi). The temperature of this dust was initially estimated as 30 K (−243.2 °C; −405.7 °F)[6] according to measurement by Herschel Space Observatory. Later that measurement was deemed questionable,[12] and fixed temperature of 62 K (−211.2 °C; −348.1 °F) was obtained in 2020.[13]