| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Dorado |
| Right ascension | 04h 55m 34.3416s[1] |
| Declination | −67° 30′ 02.683″[1] |
| Apparent magnitude (V) | 13.81[2] |
| Characteristics | |
| Evolutionary stage | Wolf-Rayet |
| Spectral type | WN4b[3] |
| U−B color index | −0.567[4] |
| B−V color index | −0.35[4] |
| Astrometry | |
| Proper motion (μ) | RA: 1.733[1] mas/yr Dec.: 0.367[1] mas/yr |
| Parallax (π) | −0.0083 ± 0.0166 mas[1] |
| Distance | 50,000 pc |
| Absolute magnitude (MV) | −5.02[3] |
| Details | |
| Mass | 25[3] M☉ |
| Radius | 1.1[3] R☉ |
| Luminosity | 692,000[3] L☉ |
| Temperature | 158,500[3] K |
| Rotational velocity (v sin i) | 160[5] km/s |
| Other designations | |
Brey 6, HD 32109, 2MASS J04553134-6730028 | |
| Database references | |
| SIMBAD | data |
BAT99-7 is a WN-type Wolf-Rayet star located in the Large Magellanic Cloud, in the constellation of Dorado, about 160,000 light years away. The star has a spectrum containing extremely broad emission lines, and is the prototype for the "round line" stars, Wolf-Rayet stars whose spectra are characterized by strong and broad emission lines with round line profiles. The broad emission lines hint at an extremely high temperature of nearly 160,000 Kelvin, which would make it the hottest of all WN stars with known temperatures, as well as an extraordinarily large mass loss rate for a Wolf-Rayet star in the LMC, at 10−4.48 M☉/yr, which means that every 30,200 years, the star loses 1 solar mass worth of mass.[3]
dr3 was invoked but never defined (see the help page).ucac4 was invoked but never defined (see the help page).hainich was invoked but never defined (see the help page).2mass was invoked but never defined (see the help page).shenar was invoked but never defined (see the help page).