V3903 Sagittarii
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 18h 09m 17.6999s |
| Declination | −23° 59′ 18.2312″ |
| Apparent magnitude (V) | 7.00–7.45 |
| Characteristics | |
| Spectral type | O7V(n)z + B0:V: |
| U−B color index | −0.82 |
| B−V color index | +0.16 |
| Variable type | Algol |
| Astrometry | |
| Proper motion (μ) | RA: +0.87±0.67 mas/yr Dec.: −0.66±0.42 mas/yr |
| Parallax (π) | 0.8368±0.0258 mas |
| Distance | 3,900 ± 100 ly (1,200 ± 40 pc) |
| Absolute magnitude (MV) | −4.59 + −3.69 |
| Orbit | |
| Period (P) | 1.744204 days |
| Eccentricity (e) | 0 |
| Inclination (i) | 65.20° |
| Semi-amplitude (K1) (primary) | 236.6 km/s |
| Semi-amplitude (K2) (secondary) | 339.4 km/s |
| Details | |
| A | |
| Mass | 27.27 M☉ |
| Radius | 8.088 R☉ |
| Luminosity | 122,000 L☉ |
| Surface gravity (log g) | 4.058 cgs |
| Temperature | 38,000 K |
| Rotational velocity (v sin i) | 230 km/s |
| B | |
| Mass | 19.01 M☉ |
| Radius | 6.125 R☉ |
| Luminosity | 45,500 L☉ |
| Surface gravity (log g) | 4.143 cgs |
| Temperature | 34,100 K |
| Rotational velocity (v sin i) | 170 km/s |
| Age | 1.6 Myr |
| Other designations | |
| V3903 Sgr, CD−24°13962, HD 165921, HIP 88943, SAO 186366 | |
| Database references | |
| SIMBAD | data |
V3903 Sagittarii (also known as 11 Sagittarii, or its abbreviation 11 Sgr) is an eclipsing binary star system in the constellation Sagittiarus. It creates an H II region LBN 29 (Sh 2-29) 1,070 parsecs (3,500 light-years) away from the Sun.
John Flamsteed designated this star the Flamsteed designation 11 Sagittarii, although the designation 11 Sgr is now more often used to refer to the star he designated 1 Sagittarii.