Astronomy:Theta Sagittae
Observation data {{#ifeq:J2000.0|J2000.0 (ICRS)|Epoch J2000.0 Equinox J2000.0 (ICRS)| [[History:Epoch|Epoch J2000.0]] [[Astronomy:Equinox (celestial coordinates)|Equinox J2000.0}} | |
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Constellation | Sagitta |
A | |
Right ascension | 20h 09m 56.6470s[1] |
Declination | +20° 54′ 54.094″[1] |
Apparent magnitude (V) | +6.516[2] |
B | |
Right ascension | 20h 09m 56.2405s[3] |
Declination | +20° 55′ 04.228″[3] |
Apparent magnitude (V) | +8.769[2] |
Characteristics | |
A | |
Spectral type | F3V[4] |
U−B color index | −0.04[5] |
B−V color index | +0.38[5] |
B | |
Spectral type | G5V[6] |
B−V color index | +0.732[2] |
Astrometry | |
A | |
Radial velocity (Rv) | −40.92[1] km/s |
Proper motion (μ) | RA: +58.387[1] mas/yr Dec.: +98.274[1] mas/yr |
Parallax (π) | 22.3262 ± 0.0326[1] mas |
Distance | 146.1 ± 0.2 ly (44.79 ± 0.07 pc) |
Absolute magnitude (MV) | +3.24[7] |
B | |
Radial velocity (Rv) | −43.0[8] km/s |
Proper motion (μ) | RA: +64.726[3] mas/yr Dec.: +101.800[3] mas/yr |
Parallax (π) | 22.3841 ± 0.0305[3] mas |
Distance | 145.7 ± 0.2 ly (44.67 ± 0.06 pc) |
Absolute magnitude (MV) | +5.58[7] |
Details | |
A | |
Mass | 1.52[9] M☉ |
Radius | 1.45[1] R☉ |
Luminosity | 4.0[1] L☉ |
Surface gravity (log g) | 4.32[9] cgs |
Temperature | 6,750±229[9] K |
Metallicity [Fe/H] | −0.17[8] dex |
Rotational velocity (v sin i) | 33.6[10] km/s |
Age | 2.089[9] Gyr |
B | |
Mass | 0.95[11] M☉ |
Radius | 0.82[3] R☉ |
Luminosity | 0.516[3] L☉ |
Surface gravity (log g) | 4.526[12] cgs |
Temperature | 5,394[3] K |
Other designations | |
A: {{{names2}}} | |
B: {{{names3}}} | |
Database references | |
SIMBAD | A |
B |
Theta Sagittae (θ Sagittae) is a double star in the northern constellation of Sagitta.[14] With a combined apparent visual magnitude of +6, it is near the limit of stars that can be seen with the naked eye. According to the Bortle scale the star is visible in dark suburban/rural skies. Based upon an annual parallax shift of 22.15 mas as seen from Earth,[15] it is located roughly 147 light years from the Sun.
The binary pair consists of two stars separated by 502 astronomical unit|AU.[16] The primary, component A,[17] is an F-type main sequence star with a stellar classification of F3V.[4] This star is about two billion years old[9] with 52% more mass than the Sun.[9] It forms a double star with a magnitude 8.85 companion,[17] which is located at an angular separation of 11.58 arc seconds along a position angle of 331.1°, as of 2011.[14] The star is sometimes described as a triple star, with a 7th magnitude companion 91″ away.[17] This is an unrelated giant star much further away than the close pair.[18] A fainter star separated by nearly 3′ was also listed as a companion by Struve,[17] again just an accidental optical association.[19]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics 355: L27, Bibcode: 2000A&A...355L..27H.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 4.0 4.1 Abt, H. A. (September 1985), "Visual multiples. VIII. 1000 MK types", Astrophysical Journal Supplement Series 59: 95–112, doi:10.1086/191064, Bibcode: 1985ApJS...59...95A.
- ↑ 5.0 5.1 Hoffleit, Dorrit; Jaschek, Carlos (1991), "The Bright star catalogue", New Haven, Bibcode: 1991bsc..book.....H.
- ↑ Adams, Walter S. et al. (April 1935), "The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars", Astrophysical Journal 81: 187, doi:10.1086/143628, Bibcode: 1935ApJ....81..187A.
- ↑ 7.0 7.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 8.0 8.1 Casagrande, L. et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics 530 (A138): 21, doi:10.1051/0004-6361/201016276, Bibcode: 2011A&A...530A.138C.
- ↑ 9.0 9.1 9.2 9.3 9.4 9.5 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ do Nascimento, J. D. Jr. et al. (July 2003), "On the link between rotation, chromospheric activity and Li abundance in subgiant stars", Astronomy and Astrophysics 405 (2): 723–731, doi:10.1051/0004-6361:20030633, Bibcode: 2003A&A...405..723D.
- ↑ Allende Prieto, C.; Lambert, D. L. (1999), "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures", Astronomy and Astrophysics 352: 555–562, Bibcode: 1999A&A...352..555A.
- ↑ McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017), "Fundamental parameters and infrared excesses of Tycho–Gaia stars", Monthly Notices of the Royal Astronomical Society 471 (1): 770–791, doi:10.1093/mnras/stx1433, Bibcode: 2017MNRAS.471..770M.
- ↑ "tet Sge". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=tet+Sge.
- ↑ 14.0 14.1 Mason, Brian D. et al. (May 2012), "Speckle Interferometry at the U.S. Naval Observatory. XVIII", The Astronomical Journal 143 (5): 6, doi:10.1088/0004-6256/143/5/124, 124, Bibcode: 2012AJ....143..124M, http://www.dtic.mil/get-tr-doc/pdf?AD=ADA561759.
- ↑ van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ Halbwachs, J.-L. et al. (May 2012), "Double stars with wide separations in the AGK3 - I. Components that are themselves spectroscopic binaries", Monthly Notices of the Royal Astronomical Society 422 (1): 14–24, doi:10.1111/j.1365-2966.2012.20308.x, Bibcode: 2012MNRAS.422...14H.
- ↑ 17.0 17.1 17.2 17.3 Mason, B. D. et al. (2014), The Washington Visual Double Star Catalog, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M
- ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
![]() | Original source: https://en.wikipedia.org/wiki/Theta Sagittae.
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