19 Arietis (abbreviated 19 Ari) is a star in the northern constellation of Aries. 19 Arietis is the Flamsteed designation. It has an apparent visual magnitude of 5.70,[2] which means it is faintly visible to the naked eye. Based upon an annual parallax shift of 6.81 mas,[1] it is approximately 480 light-years (150 parsecs) away from Earth. At that distance, the brightness of the star is diminished by 0.21 in magnitude from extinction caused by interstellar gas and dust.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 02h 13m 03.30440s[1] |
| Declination | +15° 16′ 47.5005″[1] |
| Apparent magnitude (V) | 5.70[2] |
| Characteristics | |
| Spectral type | M0 III[3] |
| U−B color index | +1.95[2] |
| B−V color index | +1.55[2] |
| R−I color index | 0.97 |
| Variable type | Semiregular[4] |
| Astrometry | |
| Radial velocity (Rv) | 21.11 ± 0.26[5] km/s |
| Proper motion (μ) | RA: +97.95[1] mas/yr Dec.: -20.30[1] mas/yr |
| Parallax (π) | 6.81 ± 0.38 mas[1] |
| Distance | 480 ± 30 ly (147 ± 8 pc) |
| Details | |
| Radius | 39.36[6] R☉ |
| Luminosity | 301.969[6] L☉ |
| Temperature | 3838±125[6] K |
| Metallicity [Fe/H] | –0.02 ± 0.11[7] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a red giant star with a stellar classification of M0 III.[3] It is a semi-regular variable with periods of 32 and 275 days; the brightness of the star changes by an amplitude of 0.14 in magnitude during those intervals.[4] 19 Arietis has expanded to 39 times the size of the Sun, its photosphere radiates 300 times the luminosity of the Sun.[6] The effective temperature of the outer envelope is 3,838 K,[6] giving it the cool reddish glow of an M-type star.[9]