Y Sagittarii

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Y Sagittarii
YSgrLightCurve.png
A light curve for Y Sagittarii, plotted from Hipparcos data [1]
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
57 G. Sgr, Y Sgr, BD−18° 4926, HD  168608, HIP  89968, HR  6863 [7]
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]

Related Research Articles

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<span class="mw-page-title-main">Phi Sagittarii</span> Blue-hued star in the constellation Sagittarius

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Xi<sup>2</sup> Sagittarii Star in the constellation Sagittarius

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.

Theta<sup>1</sup> Sagittarii Binary star system in the constellation Sagittarius

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Theta<sup>2</sup> Sagittarii Star in the constellation Sagittarius

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.

<span class="mw-page-title-main">59 Sagittarii</span> Star in the constellation Sagittarius

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<span class="mw-page-title-main">X Sagittarii</span> Variable star and possible binary star system in the constellation Sagittarius

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<span class="mw-page-title-main">9 Sagittarii</span> Star in the constellation Sagittarius

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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.

<span class="mw-page-title-main">BP Circini</span> Star in the constellation Circinus

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<span class="mw-page-title-main">U Sagittarii</span> Star in the constellation Sagittarius

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.

<span class="mw-page-title-main">RS Sagittarii</span> Eclipsing binary star system in the constellation Sagittarius

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.

References

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  3. 1 2 3 4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv: 1108.4971 , Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID   119257644.
  4. 1 2 3 4 Usenko, I. A.; et al. (July 2013), "Spectroscopic studies of southern-hemisphere Cepheids: Six objects in Centaurus (V Cen, V737 Cen) and Sagittarius (BB Sgr, W Sgr, X Sgr, Y Sgr)", Astronomy Letters, 39 (7): 432–445, Bibcode:2013AstL...39..432U, doi:10.1134/S1063773713070074, S2CID   121213614.
  5. Benedict, G. Fritz; et al. (January 2017), "Astrometry with Hubble Space Telescope Fine Guidance Sensors—A Review", Publications of the Astronomical Society of the Pacific, 129 (971): 012001, arXiv: 1610.05176 , Bibcode:2017PASP..129a2001B, doi:10.1088/1538-3873/129/971/012001, S2CID   118432032.
  6. "HIP 89968", Wolfram Alpha, retrieved 2012-09-17.
  7. "V* Y Sgr". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2012-09-17.
  8. J., Duncan (August 2013), "Changes in the spectrographic elements of Y Sagittarii", Astrophysical Journal, 56: 340–341, Bibcode:1922ApJ....56..340D, doi: 10.1086/142708 .
  9. Evans, Nancy Remage; et al. (December 2020), "Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids: Final Results", The Astrophysical Journal, 905 (1): 34, arXiv: 2010.07996 , Bibcode:2020ApJ...905...81E, doi:10.3847/1538-4357/abc1f1, S2CID   223953710, 81.