109 Tauri
Star in the constellation Taurus
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109 Tauri, or n Tauri, is a single,[6] yellow-hued star in the zodiac constellation of Taurus. It has an apparent visual magnitude of 4.96[2] and is faintly visible to the naked eye. The star has an annual parallax shift of 13.19±0.30 mas,[1] putting it around 247 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.24 due to interstellar dust.[4] It is moving further from the Sun with a heliocentric radial velocity of +19 km/s.[4]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 05h 19m 16.60169s[1] |
| Declination | +22° 05′ 47.3740″[1] |
| Apparent magnitude (V) | 4.96[2] |
| Characteristics | |
| Spectral type | G8 III[3] |
| B−V color index | 0.937±0.001[2] |
| Astrometry | |
| Radial velocity (Rv) | +19.03±0.01[4] km/s |
| Proper motion (μ) | RA: +18.91[1] mas/yr Dec.: −81.57[1] mas/yr |
| Parallax (π) | 13.19±0.30 mas[1] |
| Distance | 247 ± 6 ly (76 ± 2 pc) |
| Absolute magnitude (MV) | 0.56[2] |
| Details[4] | |
| Mass | 2.47±0.08 M☉ |
| Radius | 8.14±0.46 R☉ |
| Luminosity | 60+10 −12 L☉ |
| Surface gravity (log g) | 2.96±0.01 cgs |
| Temperature | 5,035±23 K |
| Metallicity [Fe/H] | 0.10±0.04 dex |
| Rotational velocity (v sin i) | 1.15±0.62 km/s |
| Age | 600±50 Myr |
| Other designations | |
| n Tau, 109 Tau, BD+21°816, FK5 2398, HD 34559, HIP 24822, HR 1739, SAO 77097[5] | |
| Database references | |
| SIMBAD | data |
This is an evolved giant star with a stellar classification of G8 III,[3] having consumed the hydrogen at its core and moved off the main sequence. At the age of 600[4] million years, it has become a red clump giant, indicating that it is on the horizontal branch and is generating energy through helium fusion at its core.[7] The star has an estimated 2.47 times the mass of the Sun and has expanded to around eight times the Sun's radius. It is radiating about 60 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,035 K.[4]