40 Arietis is a probable binary star[3] system in the northern constellation of Aries. 40 Arietis is the Flamsteed designation. Their combined apparent magnitude is 5.82,[2] putting the system near the limit of naked eye visibility. Based upon an annual parallax shift of just 7.33 mas,[1] it is 445 light-years (136 parsecs) away from the Sun. At that distance, its brightness is diminished by 0.21 in magnitude from extinction caused by interstellar gas and dust.[9]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aries |
Right ascension | 02h 48m 32.08864s[1] |
Declination | +18° 17′ 01.6491″[1] |
Apparent magnitude (V) | 5.82[2] |
Characteristics | |
Spectral type | K1 III[3] |
U−B color index | 1.13 |
B−V color index | +1.20[2] |
R−I color index | 0.44 |
Variable type | suspected[4] |
Astrometry | |
Radial velocity (Rv) | +47.1[5] km/s |
Proper motion (μ) | RA: +41.250[1] mas/yr Dec.: −32.585[1] mas/yr |
Parallax (π) | 7.3266 ± 0.1215 mas[1] |
Distance | 445 ± 7 ly (136 ± 2 pc) |
Absolute magnitude (MV) | 0.09[6] |
Details[7] | |
Mass | 1.60±0.48 M☉ |
Radius | 19.74+0.29 −0.96[1] R☉ |
Luminosity | 127.98±2.52[1] L☉ |
Surface gravity (log g) | 2.09±0.11 cgs |
Temperature | 4,473±92 K |
Metallicity [Fe/H] | −0.21±0.05 dex |
Age | 2.63+1.00 −0.72 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
This is a suspected spectroscopic binary with an angular separation of 0.2″ between the two components.[3] The visible component is an evolved giant star with a stellar classification of K1 III.[3] It is a suspected variable star of unknown type,[4] and is around 2.6 billion years old with 1.6 times the mass of the Sun.[7] With the supply of hydrogen at its core exhausted, the star has expanded to 20 times the Sun's radius.[1] It is radiating 128 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,473 K.[7]