Beta Scuti

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β Scuti
Scutum constellation map.svg
Red circle.svg

Location of β Scuti (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scutum
Right ascension 18h 47m 10.47250s[1]
Declination −4° 44′ 52.3271″[1]
Apparent magnitude (V) 4.22[2]
Spectral type G4IIa[3]
U−B color index +0.84[4]
B−V color index +1.09[4]
Radial velocity (Rv) -21.30[5] km/s
Proper motion (μ) RA: -8.44[1] mas/yr
Dec.: -16.37[1] mas/yr
Parallax (π) 3.56 ± 0.43[1] mas
Distance approx. 900 ly
(approx. 280 pc)
Absolute magnitude (MV) -2.99[6]
Primary Beta Scuti A
Companion Bet 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)
Luminosity 1,270[2] L
Surface gravity (log g) 0.94[8] cgs
Temperature 4,622[2] K
Metallicity [Fe/H] -0.16[6] dex
Rotational velocity (v sin i) 7.8[9] km/s
Other designations
BD-04°4582, FK5 1489, GC 25730, GSC 05122-01426, HIP 92175, HR 7063, HD 173764, SAO 142618, CCDM 18472-0445
Database references

Beta Scuti (β Sct, β Scuti) is a star in the constellation Scutum. It is approximately 920 light years from Earth.[1] The primary star is radiating about 1,270 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 4,622 K.[2] The star is a yellow G-type bright giant[3][10] with an apparent magnitude of +4.22.

It is a spectroscopic binary with an orbit of 2.3 years and eccentricity around 0.35;[11] the secondary is about 3.3 magnitudes dimmer than the primary and estimated as type B9 based on the far-ultraviolet light from the secondary.[12]

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.[13] This detection was significant as observations with the Hubble Space Telescope which indicated a companion star was present were not definitive.[14] With an orbit and a parallax the sum of the masses of the two stars can be determined via a dynamical parallax. [15] This eventually can yield a precise mass for the evolved giant primary star.

Beta Scuti was a latter designation of 6 Aquilae.[16]


  1. ^ a b c d e f Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.  Vizier catalog entry
  2. ^ a b c d Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M 
  3. ^ a b 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. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. 
  4. ^ a b 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. Bibcode:2002yCat.2237....0D. 
  5. ^ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727. arXiv:astro-ph/0406573Freely accessible. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. 
  6. ^ a b Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971Freely accessible. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.  Vizier catalog entry
  7. ^ Ren, Shulin (2013). "Hipparcos Photocentric Orbits of 72 Single-lined Spectroscopic Binaries". The Astronomical Journal. 145 (3). Bibcode:2013AJ....145...81R. doi:10.1088/0004-6256/145/3/81. 
  8. ^ Soubiran, Caroline; Le Campion, Jean-François; Brouillet, Nathalie; Chemin, Laurent (2016). "The PASTEL catalogue: 2016 version". Astronomy & Astrophysics. 591: A118. arXiv:1605.07384Freely accessible. Bibcode:2016A&A...591A.118S. doi:10.1051/0004-6361/201628497. 
  9. ^ 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. Bibcode:1999A&AS..139..433D. doi:10.1051/aas:1999401.  Vizier catalog entry
  10. ^ "Giant star - New World Encyclopedia". Retrieved 2017-03-29. 
  11. ^ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. 
  12. ^ 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: 83. Bibcode:1998ApJS..119...83P. doi:10.1086/313152. 
  13. ^ 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). Bibcode:2016ApJS..227....4H. doi:10.3847/0067-0049/227/1/4. 
  14. ^ 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. Bibcode:2005AJ....129.1700P. doi:10.1086/427853. 
  15. ^ Heintz, Wulff D. Double Stars - Springer. doi:10.1007/978-94-009-9836-0. 
  16. ^ Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy, Vol.18, NO. 3/AUG, P.209, 1987. 18: 212. Bibcode:1987JHA....18..209W. doi:10.1177/002182868701800305.