Astronomy:Alpha Scuti
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Scutum |
| Right ascension | 18h 35m 12.42776s[1] |
| Declination | −8° 14′ 38.6529″[1] |
| Apparent magnitude (V) | 3.83[2] |
| Characteristics | |
| Spectral type | K3III[3] |
| U−B color index | +1.53[2] |
| B−V color index | +1.34[2] |
| Astrometry | |
| Radial velocity (Rv) | +36.50[4] km/s |
| Proper motion (μ) | RA: −17.00[1] mas/yr Dec.: −313.52[1] mas/yr |
| Parallax (π) | 16.38 ± 0.22[1] mas |
| Distance | 199 ± 3 ly (61.1 ± 0.8 pc) |
| Absolute magnitude (MV) | −0.08[5] |
| Details | |
| Mass | 1.33[6] M☉ |
| Radius | 20[6] R☉ |
| Luminosity | 186[5] L☉ |
| Surface gravity (log g) | 1.96[6] cgs |
| Temperature | 4,315[7] K |
| Metallicity [Fe/H] | −0.04[5] dex |
| Rotational velocity (v sin i) | 1.7[8] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Alpha Scuti, Latinized from α Scuti, is an orange-hued star in the southern constellation of Scutum. Originally part of the Aquila constellation, Alpha Scuti was a latter designation of 1 Aquilae.[9] It is faintly visible to the naked eye with an apparent visual magnitude of 3.83.[2] Based upon an annual parallax shift of 16.38 mas as seen from the Earth,[1] it is located around 199 light years from the Sun. It is moving away from the Sun with a radial velocity of +36.5 km/s.[4]
Properties
With a stellar classification of K3 III,[3] the spectrum indicates it is an evolved giant star of type K. Alpha Scuti is a suspected variable star with magnitude range reported as 3.81 to 3.87.[10] The star has an estimated 1.33 times the mass of the Sun, but the outer envelope has expanded to 20 times the Sun's radius.[6] It is radiating 186[5] times the Sun's luminosity from its inflated photosphere at an effective temperature of 4,315 K.[7]
References
- ↑ 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. Bibcode: 2007A&A...474..653V. Vizier catalog entry
- ↑ 2.0 2.1 2.2 2.3 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.
- ↑ 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. Bibcode: 1989ApJS...71..245K.
- ↑ 4.0 4.1 Massarotti, Alessandro; Latham, David W.; Stefanik, Robert P.; Fogel, Jeffrey (2008). "Rotational and Radial Velocities for a Sample of 761 Hipparcos Giants and the Role of Binarity". The Astronomical Journal 135 (1): 209–231. doi:10.1088/0004-6256/135/1/209. Bibcode: 2008AJ....135..209M.
- ↑ 5.0 5.1 5.2 5.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. Vizier catalog entry
- ↑ 6.0 6.1 6.2 6.3 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. Vizier catalog entry
- ↑ 7.0 7.1 Martínez, M. Isabel Pérez; Schröder, K.-P.; Cuntz, M. (2011). "The basal chromospheric Mg ii h+k flux of evolved stars: Probing the energy dissipation of giant chromospheres". Monthly Notices of the Royal Astronomical Society 414 (1): 418–427. doi:10.1111/j.1365-2966.2011.18421.x. Bibcode: 2011MNRAS.414..418P. Vizier catalog entry
- ↑ De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics 561: A126. doi:10.1051/0004-6361/201220762. Bibcode: 2014A&A...561A.126D. Vizier catalog entry
- ↑ Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy 18 (3): 212. doi:10.1177/002182868701800305. Bibcode: 1987JHA....18..209W.
- ↑ Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1. Bibcode: 2009yCat....102025S.
External links
- EAAS: Scutum
- Kaler, James B. (April 29, 2011), "Alpha Scuti", STARS (University of Illinois), http://stars.astro.illinois.edu/sow/alphasct.html, retrieved 2017-11-09.
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