Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Leo |
Right ascension | 09h23m 47.08736s[1] |
Declination | +20° 21′ 52.0282″[1] |
Apparent magnitude (V) | +7.73[2] |
Characteristics | |
Spectral type | G0V[2] |
B−V color index | 0.680±0.012 |
Astrometry | |
Radial velocity (Rv) | +49.270±0.0017[3] km/s |
Proper motion (μ) | RA: −151.258±0.093[1] mas/yr Dec.: +36.125±0.065[1] mas/yr |
Parallax (π) | 29.0122 ± 0.0649 mas[1] |
Distance | 112.4 ± 0.3 ly (34.47 ± 0.08 pc) |
Absolute magnitude (MV) | 5.12[4] |
Details[2] | |
Mass | 0.87 M☉ |
Radius | 0.91+0.01 −0.03[1] R☉ |
Luminosity | 0.76 L☉ |
Surface gravity (log g) | 4.48 cgs |
Temperature | 5,753 K |
Metallicity [Fe/H] | −0.06±0.03[4] dex |
Rotational velocity (v sin i) | 5.3 km/s |
Age | 8.68 Gyr |
Other designations | |
BD+20°2374, FK5 4836, GC 12951, HD 81040, HIP 46076, SAO 80800, PPM 99541[5] | |
Database references | |
SIMBAD | data |
HD 81040 is a star in the equatorial constellationofLeo. With an apparent visual magnitude of +7.73[2] it is too dim to be visible to the naked eye but can be viewed with a small telescope. The star is located at a distance of 112 light years from the Sun based on parallax. It is drifting further away with a radial velocity of +49 km/s,[3] having come to within 48 light-years some 527,000 years ago.
This is an ordinary G-type main-sequence star with a stellar classification of G0V.[2] The Sun somewhat dwarfs HD 81040 in terms of physical characteristics: it has 87% of the Sun's mass and 91% of the radius of the Sun. It is spinning with a projected rotational velocity of 5.3 km/s,[2] and has near solar metallicity.[4] The age of the star is not precisely known; the ELODIE spectrograph suggested 0.8 Gyr and found it to have a young dust disk.[6] Later measurements by modelling chromosperic activity suggested an age of 4.18 Gyr.[citation needed]
On November 24, 2005, a superjovian planet was announced by Sozzetti.
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥6.86±0.71 MJ | 1.94 | 1,001.7±7.0 | 0.526±0.042 | — | — |
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