Astronomy:Beta Scuti

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Short description: Star in the constellation Scutum
β Scuti
Scutum constellation map.svg
Red circle.svg
Location of β Scuti (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Scutum
Right ascension  18h 47m 10.47250s[1]
Declination −4° 44′ 52.3271″[1]
Apparent magnitude (V) 4.22[2]
Characteristics
Spectral type G4IIa[3]
U−B color index +0.84[4]
B−V color index +1.09[4]
Astrometry
Proper motion (μ) RA: −8.44[1] mas/yr
Dec.: −16.37[1] mas/yr
Parallax (π)3.56 ± 0.43[1] mas
Distanceapprox. 900 ly
(approx. 280 pc)
Absolute magnitude (MV)−2.99[5]
Orbit[6]
PrimaryBeta Scuti A
CompanionBet Scuti B
Period (P)834 days
Semi-major axis (a)2.8 mas
Eccentricity (e)0.350
Inclination (i)105.9°
Longitude of the node (Ω)288.1°
Periastron epoch (T)2422480.9
Argument of periastron (ω)
(secondary)
33.9°
Details
Luminosity1,270[2] L
Surface gravity (log g)0.94[7] cgs
Temperature4,622[2] K
Metallicity [Fe/H]-0.16[5] dex
Rotational velocity (v sin i)7.8[8] km/s
Other designations
β Sct, BD-04°4582, FK5 1489, GC 25730, GSC 05122-01426, HIP 92175, HR 7063, HD 173764, SAO 142618, CCDM 18472-0445
Database references
SIMBADdata

Beta Scuti, Latinized from β Scuti, is a binary star system in the southern constellation Scutum. Based upon an annual parallax shift of 3.56 mas as seen from Earth,[1] it is located approximately 920 light years from the Sun. The primary component has an apparent visual magnitude of +4.22 and is radiating about 1,270 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 4,622 K.[2] This yellow-hued star is a G-type bright giant with a stellar classification of G4 IIa.[3]

This is a spectroscopic binary with an orbital period of 2.3 years and eccentricity around 0.35.[9] The secondary is about 3.3 magnitudes dimmer than the primary and estimated as type B9 based on the flux of far-ultraviolet radiation.[10]

The secondary was directly detected with a magnitude difference of 3.6 at a separation of about 17 milli-arcseconds using observations from the Navy Precision Optical Interferometer.[11] This detection was significant as observations with the Hubble Space Telescope which indicated a companion star was present were not definitive.[12] With an orbit and a parallax the sum of the masses of the two stars can be determined via a dynamical parallax.[13] This eventually can yield a precise mass for the evolved giant primary star.

Beta Scuti was a latter designation of 6 Aquilae.[14]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V.  Vizier catalog entry
  2. 2.0 2.1 2.2 2.3 Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics 352: 495–507, Bibcode1999A&A...352..495M 
  3. 3.0 3.1 Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". The Astrophysical Journal Supplement Series 71: 245. doi:10.1086/191373. Bibcode1989ApJS...71..245K. 
  4. 4.0 4.1 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode2002yCat.2237....0D. 
  5. 5.0 5.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A.  Vizier catalog entry
  6. Ren, Shulin (2013). "Hipparcos Photocentric Orbits of 72 Single-lined Spectroscopic Binaries". The Astronomical Journal 145 (3): 81. doi:10.1088/0004-6256/145/3/81. Bibcode2013AJ....145...81R. 
  7. Soubiran, Caroline; Le Campion, Jean-François; Brouillet, Nathalie; Chemin, Laurent (2016). "The PASTEL catalogue: 2016 version". Astronomy & Astrophysics 591: A118. doi:10.1051/0004-6361/201628497. Bibcode2016A&A...591A.118S. 
  8. De Medeiros, J. R.; Mayor, M. (1999). "A catalog of rotational and radial velocities for evolved stars". Astronomy and Astrophysics Supplement Series 139 (3): 433. doi:10.1051/aas:1999401. Bibcode1999A&AS..139..433D.  Vizier catalog entry
  9. Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G. et al. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics 424 (2): 727–732. doi:10.1051/0004-6361:20041213. Bibcode2004A&A...424..727P. 
  10. Parsons, Sidney B.; Ake, Thomas B. (1998). "Ultraviolet and Optical Studies of Binaries with Luminous Cool Primaries and Hot Companions. V. The Entire IUE Sample". The Astrophysical Journal Supplement Series 119 (1): 83. doi:10.1086/313152. Bibcode1998ApJS..119...83P. 
  11. Hutter, D. J.; Zavala, R. T.; Tycner, C.; Benson, J. A.; Hummel, C. A.; Sanborn, J.; Franz, O. G.; Johnston, K. J. (2016). "Surveying the Bright Stars by Optical Interferometry. I. A Search for Multiplicity among Stars of Spectral Types F-K". Astrophysical Journal Supplement Series 227 (1): 4. doi:10.3847/0067-0049/227/1/4. Bibcode2016ApJS..227....4H. 
  12. Parsons, S. B.; Franz, O. G.; Wassermann, L. H. (2005). "The Fine Guidance Sensor Orbit of the G4 Bright Giant HD 173764". Astronomical Journal 129 (3): 1700. doi:10.1086/427853. Bibcode2005AJ....129.1700P. 
  13. Heintz, Wulff D. (1978) (in en). Double Stars - Springer. 15. doi:10.1007/978-94-009-9836-0. ISBN 978-90-277-0886-1. Bibcode1978GAM....15.....H. 
  14. Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy 18 (3): 212. doi:10.1177/002182868701800305. Bibcode1987JHA....18..209W.