Astronomy:HD 175535

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Short description: Star in the constellation Draco
HD 175535
Observation data
Equinox J2000.0]] (ICRS)
Constellation Draco
Right ascension  18h 53m 13.55478s[1]
Declination +50° 42′ 59.1821″[1]
Apparent magnitude (V) 4.92[2]
Characteristics
Spectral type G7 IIIa Fe−1[3]
U−B color index 0.57[4]
B−V color index 0.90[2]
Astrometry
Radial velocity (Rv)+8.5[2] km/s
Proper motion (μ) RA: 0.938 mas/yr
Dec.: −24.171 mas/yr
Parallax (π)10.7890 ± 0.2187[1] mas
Distance302 ± 6 ly
(93 ± 2 pc)
Absolute magnitude (MV)−0.78[5]
Orbit[4]
Period (P)972.84±0.35 d
Eccentricity (e)0.342±0.006
Periastron epoch (T)53,678.2±2.4
Argument of periastron (ω)
(secondary)
190.0±1.1°
Semi-amplitude (K1)
(primary)
5.83±0.04 km/s
Details
Mass3.27[2] M
Radius13[6] R
Luminosity219[2] L
Surface gravity (log g)2.85±0.15[7] cgs
Temperature5,024±74[2] K
Metallicity [Fe/H]−0.07±0.07[7] dex
Rotational velocity (v sin i)2.3[8] km/s
Age320[2] Myr
Other designations
BD+50° 2686, HD 175535, HIP 92689, HR 7137, SAO 31241[9]
Database references
SIMBADdata

HD 175535 is a binary star system in the northern circumpolar constellation of Draco. It has an apparent visual magnitude of 4.92,[2] which is bright enough to be faintly visible to the naked eye. The system is located about 302 light years away, as determined from its annual parallax shift of 10.8 mas.[1] It is moving further from the Earth with a heliocentric radial velocity of +8.5 km/s.[2]

The binary nature of this system was announced by W. W. Campbell of the Lick Observatory in 1911. It is a single-lined spectroscopic binary with an orbital period of 2.66 years (972.84 d) and an eccentricity of 0.342. The a sin i value for the visible component is 73.4±0.6 Gm, where a is the semimajor axis and i is the (unknown) orbital inclination.[4] This indicates that the actual semimajor axis is larger than 0.49 astronomical unit|AU.[10]

The visible component appears to be an evolved giant star with a stellar classification of G7 IIIa Fe−1,[3] where the suffix notation indicates an underabundance of iron in the atmosphere. It is 320[2] million years old with 3.27[2] times the mass of the Sun and about 13[6] times the Sun's radius. The star is radiating 219[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,024 K.[2]

References

  1. 1.0 1.1 1.2 1.3 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. Bibcode2018A&A...616A...1G. 
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode2015AJ....150...88L. 
  3. 3.0 3.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode1989ApJS...71..245K 
  4. 4.0 4.1 4.2 Griffin, R. F. (October 2010), "Spectroscopic binary orbits from photoelectric radial velocities - Paper 214: HR 6790, HR 6886, HR 6901, and HR 7137", The Observatory 130: 299–314, Bibcode2010Obs...130..299G. 
  5. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  6. 6.0 6.1 Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition", Astronomy and Astrophysics 367 (2): 521–524, doi:10.1051/0004-6361:20000451, Bibcode2001A&A...367..521P. 
  7. 7.0 7.1 Prugniel, P. et al. (2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics 531: A165, doi:10.1051/0004-6361/201116769, Bibcode2011A&A...531A.165P. 
  8. De Medeiros, J. R. et al. (October 2002), "The Rotation of Binary Systems with Evolved Components", The Astrophysical Journal 578 (2): 943–950, doi:10.1086/342613, Bibcode2002ApJ...578..943D. 
  9. "HD 175535". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+175535. 
  10. The maximum value of the sine function is 1.0; hence, 'a' is no smaller than the value cited.