Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Sagittarius |
Right ascension | 18h 21m 22.98643s [2] |
Declination | −18° 51′ 36.0018″ [2] |
Apparent magnitude (V) | 5.76 [3] |
Characteristics | |
Spectral type | F8 II [4] |
B−V color index | 0.67±0.02 [3] |
Variable type | Cepheid variable [4] |
Astrometry | |
Radial velocity (Rv) | −1.4±2.3 [3] km/s |
Proper motion (μ) | RA: −3.12 [2] mas/yr Dec.: −7.12 [2] mas/yr |
Parallax (π) | 2.13 ± 0.29 mas [5] |
Distance | approx. 1,500 ly (approx. 470 pc) |
Absolute magnitude (MV) | −2.06 [3] |
Details | |
Surface gravity (log g) | 1.80 [4] cgs |
Temperature | 5,967±26 [4] K |
Age | 330 [6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Y Sagittarii is a variable star in the constellation of Sagittarius. It is a Cepheid variable with an apparent magnitude that ranges around +5.77. The measure of its parallax by Hubble Space Telescope puts Y Sagittarii to 1,293 light-years away from the Solar System.
The brightness ranges in Y Sagittarii's apparent magnitude varies from +5.25 and +6.24 in a period of 5.7736 days. The spectral type of this star is F8II, while the effective temperature is 5370 K. It has a radius 50 times larger than the Sun, while its projected rotational velocity of 16 km / s and it has an estimated mass six times that of the Sun. The star's metal content is similar to Sun, with an index of metallicity [Fe / H] = +0.05. For other metals tested, it shows some overabundance of copper, zinc, yttrium and sodium; the level of the elements is almost double that of the Sun ([Na / H] = +0.27). [8]
There is evidence that Y Sagittarii may be a spectroscopic binary. It has been suggested that the orbital period for the system is on the order of 10,000 to 12,000 days. However, subsequent studies assume eccentricity zero for orbit, and they have failed to find a convincing orbital solution. Instead, it appears to be a distant visual companion. [9]
Alpha Sagittarii, also named Rukbat, is a star in the constellation of Sagittarius.
Gamma² Sagittarii, formally named Alnasl, is a 3rd-magnitude star in the zodiac constellation of Sagittarius. The location of this star is in the handle of the Bow of Sagittarius the Centaur. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 96.9 light-years from the Sun. It has an apparent visual magnitude of +2.98, making it the seventh-brightest star in the constellation.
W Sagittarii is a multiple star system star in the constellation Sagittarius, and a Cepheid variable star.
Phi Sagittarii, Latinized from φ Sagittarii, is a star in the southern constellation of Sagittarius. With an apparent visual magnitude of 3.17, it is the ninth-brightest star in the constellation and is readily visible to the naked eye. Parallax measurements place it at a distance of roughly 239 light-years from the Earth. It is receding with a radial velocity of +21.5 km/s.
Xi2 Sagittarii, Latinized from ξ2 Sagittarii, is a star in the zodiac constellation of Sagittarius. Data collected during the Hipparcos mission suggests it is an astrometric binary, although nothing is known about the companion. It is visible to the naked eye with a combined apparent visual magnitude of +3.51. Based upon an annual parallax shift of 8.93 mas as seen from Earth, this system is located around 370 light years from the Sun.
Theta1 Sagittarii (θ1 Sagittarii) is a close binary star system in the zodiac constellation of Sagittarius. It is visible to the naked eye with an apparent visual magnitude of 4.37. Based upon an annual parallax shift of 6.29 mas as seen from Earth, this star is located around 520 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.24 due to interstellar dust.
Theta2 Sagittarii, Latinized from θ2 Sagittarii, is a solitary star in the zodiac constellation of Sagittarius. It is faintly visible to the naked eye with an apparent visual magnitude of +5.30. The star is progressing in the general direction of the Sun with a radial velocity of −17.60 km/s. Based upon an annual parallax shift of 20.62 mas as seen from Earth, it is located around 158 light years from the Sun. The star is drifting closer with a radial velocity of −17.6 km/s.
59 Sagittarii is a single star in the southern constellation of Sagittarius, about a degree to the south of Omega Sagittarii near the constellation border with Capricornus. It has the Bayer designation b Sagittarii, or sometimes b1 Sagittarii, while 59 Sagittarii is the Flamsteed designation. The star is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.544. It forms the southeast corner of the asterism called the Terebellum. Based upon parallax measurements, the star is located approximately 830 light years away from the Sun. It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.
Upsilon Sagittarii is a spectroscopic binary star system in the constellation Sagittarius. Upsilon Sagittarii is the prototypical hydrogen-deficient binary (HdB), and one of only four such systems known. The unusual spectrum of hydrogen-deficient binaries has made stellar classification of Upsilon Sagittarii difficult.
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.
Psi Sagittarii, which is Latinized from ψ Sagittarii, is a triple star system in the zodiac constellation of Sagittarius. The star system is located at a distance of 298 light years from the Earth based on parallax, but is drifting closer with a heliocentric radial velocity of −12 km/s. The system is faintly visible to the naked eye has a combined apparent visual magnitude of +4.86.
V382 Carinae, also known as x Carinae, is a yellow hypergiant in the constellation Carina. It is a G-type star with a mean apparent magnitude of +3.93, and a variable star of low amplitude.
V Centauri is a Classical Cepheid variable, a type of variable star, in the constellation Centaurus. It is approximately 2,350 light-years away based on parallax.
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.
15 Sagittarii is a blue-hued binary star system in the southern zodiac constellation of Sagittarius. The estimated distance based upon photometry is around 4,200 ly (1,300 pc). It is faintly visible to the naked eye with an apparent visual magnitude of 5.37. The system is moving closer to the Sun with a heliocentric radial velocity of around −6 km/s.
16 Sagittarii is a multiple star system in the southern zodiac constellation of Sagittarius. It is near the lower limit of brightness for stars that can be seen with the naked eye, having an apparent visual magnitude of 6.02. The estimated distance to this system is about 4,600 light years. It is a member of the Sgr OB7 cluster. Along with the O-type star 15 Sgr, it is ionizing an H II region along the western edge of the molecular cloud L291.
BP Circini is a binary star system in the southern constellation of Circinus. It is located at a distance of approximately 3,300 light years from the Sun based on parallax.
U Sagittarii is a variable star in the southern constellation of Sagittarius, abbreviated U Sgr. It is a classical Cepheid variable that ranges in brightness from an apparent visual magnitude of 6.28 down to 7.15, with a pulsation period of 6.745226 days. At its brightest, this star is dimly visible to the naked eye. The distance to this star is approximately 2,080 light years based on parallax measurements, and it is drifting further away with a radial velocity of 2 km/s.
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.