HR 4796
A dust ring encircles HR 4796's primary star | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| A | |
| Right ascension | 12h 36m 01.0318s |
| Declination | −39° 52′ 10.223″ |
| Apparent magnitude (V) | 5.77 |
| B | |
| Right ascension | 12h 36m 00.5491s |
| Declination | −39° 52′ 15.694″ |
| Apparent magnitude (V) | 13.30 |
| Characteristics | |
| A | |
| Evolutionary stage | main sequence |
| Spectral type | A0 V |
| B−V color index | +0.01 |
| B | |
| Evolutionary stage | pre-main-sequence |
| Spectral type | M2.5 V |
| Astrometry | |
| A | |
| Radial velocity (Rv) | +10.95±0.59 km/s |
| Proper motion (μ) | RA: −55.653 mas/yr Dec.: −23.880 mas/yr |
| Parallax (π) | 14.1300±0.0471 mas |
| Distance | 230.8 ± 0.8 ly (70.8 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.46 |
| B | |
| Radial velocity (Rv) | +6.27±6.72 km/s |
| Proper motion (μ) | RA: −59.064 mas/yr Dec.: −30.026 mas/yr |
| Parallax (π) | 14.1490±0.0220 mas |
| Distance | 230.5 ± 0.4 ly (70.7 ± 0.1 pc) |
| Absolute magnitude (MV) | +8.99 |
| Details | |
| Component A | |
| Mass | 2.18±0.10 M☉ |
| Radius | 1.68 R☉ |
| Luminosity | 23 L☉ |
| Surface gravity (log g) | 4.43 cgs |
| Temperature | 9,378 K |
| Metallicity [Fe/H] | –0.03 dex |
| Rotational velocity (v sin i) | 152 km/s |
| Age | 8±2 Myr |
| Component B | |
| Mass | 0.3 M☉ |
| Radius | 0.89 R☉ |
| Luminosity | 0.130 L☉ |
| Surface gravity (log g) | 4.26 cgs |
| Temperature | 3,664 K |
| Rotational velocity (v sin i) | 12.1 km/s |
| Age | 8±2 Myr |
| Other designations | |
| CD−39°7717, CPD−39°5622, GC 17164, HD 109573, HIP 61498, HR 4796, SAO 203621, CCDM J12360-3952, 2MASS J12360103-3952102 | |
| Database references | |
| SIMBAD | data |
HR 4796 is a binary star system in the southern constellation of Centaurus. Parallax measurements put it at a distance of 235 light-years (72 parsecs) from the Earth. The two components of this system have an angular separation of 7.7 arcseconds, which, at their estimated distance, is equivalent to a projected separation of about 560 Astronomical Units (AU), or 560 times the separation of the Earth from the Sun. The star and its ring resemble an eye, and it is sometimes known by the nickname "Sauron's Eye".