15 Arietis
Single, variable star in the constellation Aries
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15 Arietis (abbreviated 15 Ari) is a single[9] variable star in the northern constellation of Aries. 15 Arietis is the Flamsteed designation; it also bears the variable star designation AV Arietis. It has an apparent visual magnitude of 5.74,[9] which is just bright enough to be visible to the naked eye from dark suburban skies. An annual parallax shift of 5.84 mas[2] corresponds to a physical distance of approximately 560 light-years (170 parsecs) from Earth. At that distance, the star's brightness is reduced by 0.33[6] in magnitude because of extinction from interstellar gas and dust.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 02h 10m 37.59642s[2] |
| Declination | +19° 30′ 01.2099″[2] |
| Apparent magnitude (V) | 5.67 - 5.74[3] |
| Characteristics | |
| Evolutionary stage | AGB[4] |
| Spectral type | M3 III[1] |
| U−B color index | +1.91[5] |
| B−V color index | +1.64[5] |
| Variable type | SRs[3] |
| Astrometry | |
| Radial velocity (Rv) | +62.04 ± 0.22[6] km/s |
| Proper motion (μ) | RA: +87.88[2] mas/yr Dec.: -27.82[2] mas/yr |
| Parallax (π) | 5.84±0.49 mas[2] |
| Distance | 560 ± 50 ly (170 ± 10 pc) |
| Absolute magnitude (MV) | −0.9[7] |
| Details | |
| Mass | 1.4[7] M☉ |
| Radius | 87[7] R☉ |
| Luminosity | 781[8] L☉ |
| Temperature | 3,565[8] K |
| Other designations | |
| AV Arietis, BD+18°277, FK5 1056, HD 13325, HIP 10155, HR 631, SAO 92822 | |
| Database references | |
| SIMBAD | data |
This is a red giant star with a stellar classification of M3 III.[1] The measured angular diameter of this star is 3.67 ± 0.11 mas.[10] At its estimated distance,[2] this yields a physical size of about 67 times the radius of the Sun.[11] The radius determined from the observed brightness and colour of the star is 87 R☉.[7]
15 Arietis is a short period semiregular variable with the designation AV Arietis. The period given in the General Catalogue of Variable Stars is 5.032 days.[3] Longterm photometry finds that the strongest pulsation period is 18.1 days with an amplitude of 0.028 magnitudes, while a second is 21.9 days and 0.030 in magnitude.[1]
