7 Arietis
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Aries |
| Right ascension | 01h 55m 51.03925s[1] |
| Declination | +23° 34′ 38.3465″[1] |
| Apparent magnitude (V) | 5.76[2] |
| Characteristics | |
| Spectral type | K1 III[3] |
| U−B color index | +1.04[4] |
| B−V color index | +1.185[4] |
| Astrometry | |
| Radial velocity (Rv) | +15.95[5] km/s |
| Proper motion (μ) | RA: +11.44[1] mas/yr Dec.: -10.05[1] mas/yr |
| Parallax (π) | 5.85 ± 0.46[1] mas |
| Distance | 560 ± 40 ly (170 ± 10 pc) |
| Details | |
| Radius | 21[6] R☉ |
| Rotational velocity (v sin i) | 1.8 ± 1.0[7] km/s |
| Other designations | |
7 Arietis (abbreviated 7 Ari) is a binary star[3] system in the northern constellation of Aries. 7 Arietis is the Flamsteed designation. The pair have a combined apparent visual magnitude of 5.76,[2] making it faintly visible to the naked eye from dark suburban skies. Based upon an annual parallax shift of 5.85 mas,[1] it is approximately 560 light-years (170 parsecs) distant from the Earth, give or take a 40 light-year margin of error.
This is an eclipsing binary system with a period of 47.9 days and has the variable star designation RR Arietis. During each eclipse of the primary star, the magnitude of the system decreases by 0.40. The eclipse of the secondary reduces the magnitude by 0.35.[8] The primary component of the system is an evolved giant star with a stellar classification of K1 III.[3] The measured angular diameter of this star is 1.14 ± 0.02 mas.[2] At the estimated distance of 7 Arietis,[1] this yields a physical size of about 21 times the radius of the Sun.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 3.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 4.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 6.0 6.1 Lua error in package.lua at line 80: module 'strict' not found. The radius (R*) is given by:
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
