CD−73°375
Binary star in the constellation Volans
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CD−73°375 is a binary star located in the constellation Volans about 820 light years away. The two components, HR 2979 and HR 2980, are separated by two arc-seconds. The pair has a combined apparent magnitude of 6.34. It has a radial velocity of about 13 km/s, which means it is drifting away from the Solar System.
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Volans |
| A | |
| Right ascension | 07h 35m 21.656s[1] |
| Declination | −74° 16′ 29.83″[1] |
| Apparent magnitude (V) | 7.08[2] |
| B | |
| Right ascension | 07h 35m 22.036s[3] |
| Declination | −74° 16′ 30.96″[3] |
| Apparent magnitude (V) | 7.02[2] |
| Characteristics | |
| Evolutionary stage | subgiant |
| Spectral type | B9IV + B9IV[4] |
| Astrometry | |
| A | |
| Radial velocity (Rv) | +13.0[5] km/s |
| Proper motion (μ) | RA: −2.527±0.040 mas/yr[1] Dec.: 21.791±0.033 mas/yr[1] |
| Parallax (π) | 3.9430±0.0292 mas[1] |
| Distance | 827 ± 6 ly (254 ± 2 pc) |
| B | |
| Radial velocity (Rv) | +10.8[5] km/s |
| Proper motion (μ) | RA: −3.650±0.032 mas/yr[3] Dec.: 18.164±0.034 mas/yr[3] |
| Parallax (π) | 3.9907±0.0274 mas[3] |
| Distance | 817 ± 6 ly (251 ± 2 pc) |
| Details | |
| A | |
| Mass | 3.5[6] M☉ |
| Radius | 3.6[7] R☉ |
| Luminosity | 582[8] L☉ |
| Surface gravity (log g) | 3.96[6] cgs |
| Temperature | 13,005[6] K |
| Metallicity [Fe/H] | −0.15[6] dex |
| Rotational velocity (v sin i) | 17[8] km/s |
| B | |
| Mass | 3.4[6] M☉ |
| Surface gravity (log g) | 3.93[6] cgs |
| Temperature | 12,640[6] K |
| Metallicity [Fe/H] | −0.15[6] dex |
| Other designations | |
| CD−73°375, HIP 36914, WDS J07354-7417 | |
| A: HD 62153, HR 2979 | |
| B: HD 62154, HR 2980 | |
| Database references | |
| SIMBAD | data |
| A | |
| B | |
Properties
The two stars making up CD−73°375 are both B9 subgiants with almost identical properties. HR 2979 is generally designated as the primary because of its higher mass, although HR 2980 is marginally brighter at magnitude 7.02. They are 1.9″ apart and have an assumed orbit of 3,760 years.[9]
Each star has a mass about three and a half times the Sun's and a temperature of about 13,000 K.