Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ara |
Right ascension | 16h 39m 44.726s [2] |
Declination | −56° 59′ 39.92″ [2] |
Apparent magnitude (V) | 6.17 (- 6.20) - 7.32 [3] |
Characteristics | |
Spectral type | B9Vp [4] (B5V + F1IV [5]) |
B−V color index | 0.10 [5] |
Variable type | Algol [4] |
Astrometry | |
Radial velocity (Rv) | +5.5 [5] km/s |
Proper motion (μ) |
RA: −4.991
[6]
mas/
yr Dec.: −17.810 [6] mas/ yr |
Parallax (π) | 3.3603 ± 0.0647 mas [6] |
Distance | 970 ± 20
ly (298 ± 6 pc) |
Absolute magnitude (MV) | −0.48 + 0.00 [5] |
Orbit [5] | |
Period (P) | 4.425 d |
Eccentricity (e) | 0 |
Inclination (i) | 78.0° |
Semi-amplitude (K1) (primary) | 55.3 km/s |
Semi-amplitude (K2) (secondary) | 181.6 km/s |
Details [5] | |
A | |
Mass | 5.0 M☉ |
Radius | 3.41 R☉ |
Luminosity | 257 L☉ |
Surface gravity (log g) | 4.07 cgs |
Temperature | 12,500 K |
Rotational velocity (v sin i) | 202 [5] km/s |
B | |
Mass | 1.5 M☉ |
Radius | 5.97 R☉ |
Luminosity | 78 L☉ |
Surface gravity (log g) | 3.07 cgs |
Temperature | 7,000 K |
Rotational velocity (v sin i) | 73 km/s |
Other designations | |
Database references | |
SIMBAD | data |
R Arae is an Algol-type eclipsing binary in the constellation Ara. Located approximately 298 parsecs (970 ly) distant, it normally shines at magnitude 6.17, but during eclipses can fall as low as magnitude 7.32. [3] It has been suggested by multiple studies that mass transfer is occurring between the two stars of this system, [7] [8] and the period of eclipses seems to be increasing over time. [8] The primary is a blue-white main sequence star of spectral type B5V that is 5 times as massive as the Sun, while the secondary is a yellow-white star of spectral type F1IV that is 1.5 times as massive as the Sun. Stellar material is being stripped off the secondary and accreting on the primary. [5]
R Arae has an 8th-magnitude companion 3 ″ away. [5] The companion star is at a similar distance. [9]