Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Sagittarius |
Right ascension | 18h 09m 17.6999s [2] |
Declination | −23° 59′ 18.2312″ |
Apparent magnitude (V) | 7.00–7.45 [3] |
Characteristics | |
Spectral type | O7V(n)z + B0:V: [4] |
U−B color index | −0.82 [5] |
B−V color index | +0.16 [5] |
Variable type | Algol [6] |
Astrometry | |
Proper motion (μ) | RA: +0.87±0.67 [7] mas/yr Dec.: −0.66±0.42 [7] mas/yr |
Parallax (π) | 0.8368 ± 0.0258 mas [8] |
Distance | 3,900 ± 100 ly (1,200 ± 40 pc) |
Absolute magnitude (MV) | −4.59 + −3.69 [6] |
Orbit [6] | |
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 [6] | |
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 | |
Database references | |
SIMBAD | data |
V3903 Sagittarii (also known as 11Sagittarii, 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. [9]
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. [10]
The system consists of two hot main-sequence stars. The spectral types have historically been accepted as O7V and O9V, [11] but the more recent Galactic O-Star Spectroscopic Survey gives a spectral type of O7V(n)z + B0:V:. [4] The system is one of the youngest-known eclipsing binaries, and one of the few containing such massive stars that have not yet filled their roche lobes. Their likely age is around 1.6 million years, and they have current masses of 27 M☉ and 19 M☉. [6]
V3903 Sagittarii varies in brightness. The General Catalogue of Variable Stars lists it as a possible hot irregular Orion variable star, but it has been shown to be a detached eclipsing binary system. The two stars are detached, that is they do not fill their roche lobes, which makes it an Algol-type eclipsing variable. The period is one day, 18 hours, 52 minutes. [11] [6]
The distance derived from the annual parallax measured by the Hipparcos satellite is around 459 parsecs (1,500 ly), [7] but the distance calculated from the physical properties of the two stars is 1,500 pc. [6] Later measurements have resulted in refined distances estimates of 1,070 pc [9] and 1,200 pc. [8]
W Sagittarii is a multiple star system star in the constellation Sagittarius, and a Cepheid variable star.
X Sagittarii is a variable star and candidate binary star system in the southern constellation of Sagittarius, near the western constellation boundary with Ophiuchus. It has a yellow-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around 4.54. The star is located at a distance of approximately 950 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −10 km/s. The star has an absolute magnitude of around −2.85.
26 Andromedae, abbreviated 26 And, is a binary star system in the constellation Andromeda. 26 Andromedae is the Flamsteed designation. It has a combined apparent visual magnitude of 6.10, which is near the lower limit of visibility to the naked eye. The distance to this system can be estimated from its annual parallax shift of 5.35 mas, which yields a distance of about 600 light years. At that distance, the visual magnitude of the stars is diminished from an extinction of 0.04 due to interstellar dust. The system is moving further from the Earth with a heliocentric radial velocity of +3.3 km/s.
AR Aurigae, also known by its Flamsteed designation 17 Aurigae, is a binary star in the constellation Auriga. Based on parallax measurements made by the Hipparcos spacecraft, it is approximately 461 light-years from Earth.
CS Camelopardalis is a binary star in reflection nebula VdB 14, in the constellation Camelopardalis.
KW Sagittarii is a red supergiant star, located approximately 2,420 parsecs away from the Sun in the direction of the constellation Sagittarius. It is one of the largest known stars, with a diameter about 1,000 times larger than the Sun. If placed at the center of the Solar System, the star's surface would engulf Mars, coming close to Jupiter's orbit.
Zeta Cephei is a red supergiant star, located about 1000 light-years away in the constellation of Cepheus. Zeta Cephei marks the left shoulder of Cepheus, the King of Ethiopia. It is one of the fundamental stars of the MK spectral sequence, defined as type K1.5 Ib.
HD 95109 is a Classical Cepheid variable, a type of variable star, in the constellation Carina. Its apparent magnitude is 6.86.
S Monocerotis, also known as 15 Monocerotis, is a massive multiple and variable star system located in the constellation Monoceros. It is the brightest star in the Christmas Tree open cluster in the area catalogued as NGC 2264.
V4381 Sagittarii is a variable star in the constellation Sagittarius. A white supergiant of spectral type A2/A3Iab, it is an Alpha Cygni variable that varies between apparent photographic magnitudes 6.57 and 6.62. Its visual apparent magnitude is about 6.54.
1 Persei is an eclipsing binary star in the constellation Perseus. Its uneclipsed apparent magnitude is 5.49. The binary star consists of two B2 type main-sequence stars in a 25.9 day eccentric orbit. The stars are surrounded by a faint cloud of gas visible in mid-infrared, although whether they are the origin of the gas or simply passing through it is unclear.
QZ Puppis is a class B2.5V star in the constellation Puppis. Its apparent magnitude is 4.5 and it is approximately 650 light years away based on parallax.
9 Persei is a single variable star in the northern constellation Perseus, located around 4,300 light years away from the Sun. It has the Bayer designation i Persei; 9 Persei is the Flamsteed designation. This body is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of about 5.2. It is moving closer to the Sun with a heliocentric radial velocity of −15.2 km/s. The star is a member of the Perseus OB1 association of co-moving stars.
31 Cygni, also known as ο1 Cygni, Omicron1 Cygni, ο2 Cygni or V695 Cygni, is a ternary star system about 750 light years away in the constellation Cygnus.
ZZ Boötis is a star system in the constellation Boötes. It varies from magnitude 6.79 to 7.44 over five days. Based on its parallax, measured by the Gaia spacecraft, it is about 350 light-years away.
WR 20a is an eclipsing binary star belonging to or recently ejected from the young, massive cluster Westerlund 2. It was discovered in 2004 to be one of the most massive binary systems known, for which the masses of the components have been accurately measured.
Psi2 Orionis a binary star system in the equatorial constellation of Orion. It has an apparent visual magnitude of 4.6, indicating that it is visible to the naked eye. Based upon an annual parallax shift of 2.87 mass, it is roughly 1,100 light years distant from the Sun.
HD 151932, also known as WR 78, is a Wolf-Rayet star located in the constellation Scorpius, close to the galactic plane. Its distance is around 1,300 parsecs away from the Earth. Despite being a blue-colored Wolf-Rayet star, it is extremely reddened by interstellar extinction, so its apparent magnitude is brighter for longer-wavelength passbands. HD 151932 lies about 22′ west of the open cluster NGC 6231, the center of the OB association Scorpius OB1; it is not clear whether it is a part of the association or not. With an apparent magnitude of about 6.5, it is one of the few Wolf-Rayet stars that can be seen with the naked eye.
HD 150193 is a binary star system in the constellation of Ophiuchus. The primary star was identified as a Herbig Ae/Be star with a strong solar wind, losing approximately a tenth of solar mass per million years. It does host a very small debris disk, likely due to disk truncation by the nearby stellar companion. The disk is inclined 38±9° to the plane of sky. It appears to be highly evolved and asymmetric, with indications of flattening and grains growth.
RS Sagittarii is an eclipsing binary star system in the southern constellation of Sagittarius, abbreviated RS Sgr. It is a double-lined spectroscopic binary with an orbital period of 2.416 days, indicating that the components are too close to each other to be individually resolved. The system has a combined apparent visual magnitude of 6.01, which is bright enough to be faintly visible to the naked eye. During the primary eclipse the brightness drops to magnitude 6.97, while the secondary eclipse is of magnitude 6.28. The distance to this system is approximately 1,420 light years based on parallax measurements.