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]
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.
Zeta Andromedae is a star system in the constellation Andromeda. It is approximately 189 light-years from Earth.
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.
7 Arietis is a binary star system in the northern constellation of Aries. 7 Arietis is the Flamsteed designation. The pair have a combined apparent visual magnitude of 5.76, making it faintly visible to the naked eye from dark suburban skies. Based upon an annual parallax shift of 5.39 mas, it is approximately 600 light-years distant from the Earth, give or take a 30 light-year margin of error. It is drifting further away from the Sun with a radial velocity of +16 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.
3 Centauri is a triple star system in the southern constellation of Centaurus, located approximately 300 light years from the Sun. It is visible to the naked eye as a faint, blue-white hued star with a combined apparent visual magnitude of 4.32. As of 2017, the two visible components had an angular separation of 7.851″ along a position angle of 106°. The system has the Bayer designation k Centauri; 3 Centauri is the Flamsteed designation. It is a suspected eclipsing binary with a variable star designation V983 Centauri.
KW Sagittarii is a red supergiant, located approximately 1,900 parsecs away from the Sun in the direction of the constellation Sagittarius. It is one of the largest-known stars. If placed at the center of the Solar System, the star's surface would engulf Mars.
32 Cygni is the Flamsteed designation for a binary star system in the Cygnus constellation. It is a 4th magnitude star, which can be seen with the naked eye under suitably dark skies. Parallax measurements give an estimated distance of 1,100 light-years (320 parsecs) from the Earth. However, Schröder et al. (2007) suggest the actual value, after correcting for Malmquist bias, may be closer to 1,174 light-years (360 parsecs). Although it is a spectrsocopic binary with components that cannot be separated visually, it has two entries in the Henry Draper Catalogue, with identical magnitudes and positions, but showing the spectral types of the two components.
R Arae is an Algol-type eclipsing binary in the constellation Ara. Located approximately 298 parsecs (970 ly) distant, it normally shines at magnitude 6.17, but during eclipses can fall as low as magnitude 7.32. It has been suggested by multiple studies that mass transfer is occurring between the two stars of this system, and the period of eclipses seems to be increasing over time. The primary is a blue-white main sequence star of spectral type B5V that is 5 times as massive as the Sun, while the secondary is a yellow-white star of spectral type F1IV that is 1.5 times as massive as the Sun. Stellar material is being stripped off the secondary and accreting on the primary.
101 Virginis is a red giant variable star in the Boötes constellation, currently on the asymptotic giant branch. It was originally catalogued as 101 Virginis by Flamsteed due to an error in the position. When it was confirmed as a variable star, it was actually within the border of the constellation Bootes and given the name CY Boötis.
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.
9 Sagittarii is a massive binary star in the constellation Sagittarius. It has an apparent magnitude of 5.97. Both components are highly luminous O-type main-sequence stars.
43 Sagittarii is a single star in the southern constellation of Sagittarius. It has the Bayer designation d Sagittarii, while 43 Sagittarii is the Flamsteed designation. This object is visible to the naked eye as a faint, yellow-hued star with an apparent visual magnitude of 4.88. From parallax measurements, it is estimated to lie around 470 light years away from the Sun. The star is drifting further from the Earth with a heliocentric radial velocity of +15.2 km/s. It is located near the ecliptic and thus is subject to lunar occultations.
14 Lacertae is a binary star system in the northern constellation Lacerta, located around 1,600 light years away. It has the variable star designation V360 Lacertae; 14 Lacertae is the Flamsteed designation. The system is barely visible to the naked eye in good seeing conditions, having a peak apparent visual magnitude of 5.91. It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.
42 Persei is a binary star system in the northern constellation of Perseus. It has the Bayer designation n Persei, while 42 Persei is the Flamsteed designation. The system is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude of 5.11. It is located around 93 parsecs (302 ly) distant from the Sun, but is drifting closer with a radial velocity of −12.4 km/s.
31 Cygni, also known as ο1 Cygni, Omicron1 Cygni, or V695 Cygni, is a triple star system about 750 light years away in the constellation Cygnus.
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.
16 Lacertae is a triple star system in the northern constellation of Lacerta, located about 1,580 light years from the Sun. It has the variable star designation EN Lacertae; 16 Lacertae is the Flamsteed designation. This system is visible to the naked eye as a faint blue-white hued star with a maximum apparent visual magnitude of +5.587. It is moving closer to the Earth with a heliocentric radial velocity of –12 km/s.
HD 139319 is a ternary system composed of the binary Algol variable star known as TW Draconis, and a main-sequence companion star at a separation of 3 arcseconds. The system lies in the constellation of Draco about 540 light years away.
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.