WR 86
Visual binary star system
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WR 86 is a visual binary in the constellation Scorpius consisting of a Wolf-Rayet star and a β Cephei variable. It lies 2° west of NGC 6357 on the edge of the Great Rift in the Milky Way in the tail of the Scorpion.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Scorpius[2] |
| Right ascension | 17h 18m 23.06137s[3] |
| Declination | −34° 24′ 30.6308″[3] |
| Apparent magnitude (V) | 9.27[4] |
| Characteristics | |
| Evolutionary stage | Wolf-Rayet star[5] |
| Spectral type | WC7 + B0III[5] |
| Apparent magnitude (J) | 7.436[6] |
| Apparent magnitude (K) | 6.666[7] |
| U−B color index | −0.07[8] |
| B−V color index | +0.63[8] |
| Variable type | β Cep[4] |
| Astrometry | |
| Proper motion (μ) | RA: −0.92[3] mas/yr Dec.: −4.80[3] mas/yr |
| Parallax (π) | 1.84±1.62 mas[3] |
| Distance | 2,100±800[5] pc |
| Absolute magnitude (MV) | −4.3 + −4.3[5] |
| Details | |
| WR | |
| Radius | 10[9] R☉ |
| Luminosity | 200,000[5][9] L☉ |
| Temperature | 56,000[9] K |
| B | |
| Mass | 19 M☉ |
| Radius | ~8.5 (SBL) R☉ |
| Luminosity | 63,000[5] L☉ |
| Temperature | 31,405[5] K |
| Age | 4.0[5] Myr |
| Other designations | |
| V1035 Scorpii, CD−34°11622, HD 156327, HIP 84655, 2MASS J17182306-3424306, WDS J17184-3425 | |
| Database references | |
| SIMBAD | data |
WR 86 is a binary with two components of equal visual brightness 0.3" apart.[10] One has the emission-line spectrum of a WC7 Wolf-Rayet star, while the other is a B0 giant. Peter Monderen et al. discovered that the star is a variable star, in April 1986.[11] It was given its variable star designation, V1035 Scorpii, in 1997.[12] The blue giant varies slightly in brightness every 3.5 hours. The WR star may also be slightly variable.[5]
The pulsations of the B-type giant are characteristic of a β Cephei variable. Analysis of its pulsations and comparison to the expected properties of a WC7 star suggest that both stars could have evolved without mass exchange. The WR and B stars would have had initial masses of 40 M☉ and 20 M☉ respectively four million years ago.[5]