Astronomy:32 Aquarii

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Short description: Binary star system in the constellation Aquarius
32 Aquarii
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Aquarius
Right ascension  22h 04m 47.42197s[1]
Declination −00° 54′ 22.8469″[1]
Apparent magnitude (V) 5.29[2]
Characteristics
Spectral type A5 IV[3] or Am (A5/A9V/F2)[4]
B−V color index 0.231±0.004[2]
Astrometry
Radial velocity (Rv)18.9±4.2[2] km/s
Proper motion (μ) RA: −19.69[5] mas/yr
Dec.: −42.15[5] mas/yr
Parallax (π)14.4329 ± 0.1784[1] mas
Distance226 ± 3 ly
(69.3 ± 0.9 pc)
Absolute magnitude (MV)1.12[2]
Orbit[6]
Period (P)7.83238±0.00002 d
Eccentricity (e)0
Periastron epoch (T)53,420.2304±0.0001 HJD
Argument of periastron (ω)
(secondary)
Semi-amplitude (K1)
(primary)
7.2150±0.4 km/s
Details
Mass1.69[7] M
Radius2.97+0.17
−0.07
[1] R
Luminosity29.4±0.4[1] L
Surface gravity (log g)4.11[7] cgs
Temperature7,976±271[7] K
Metallicity [Fe/H]0.26±0.12[8] dex
Rotational velocity (v sin i)9.6[6] km/s
Age465[7] Myr
Other designations
32 Aqr, BD−01°4242, HD 209625, HIP 108991, HR 8410, SAO 145853[9]
Database references
SIMBADdata

32 Aquarii is a binary star system in the zodiac constellation of Aquarius. 32 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim, white-hued star with an apparent visual magnitude of 5.29.[2] This system is moving away from the Earth with a heliocentric radial velocity of +19 km/s,[2] and is a possible member of the corona of the Ursa Major flow.[10]

This is a single-lined spectroscopic binary with an (assumed) circular orbit having a period of only 7.8 days. It has an a sin i value of 0.777 Gm (0.00519 astronomical unit|AU),[6] where a is the semimajor axis and i is the orbital inclination. Since the sine function can be no larger than one, this provides a lower bound on the true semimajor axis of their orbit.

The primary component is a metallic-line (Am) star[6] with the calcium K line of an A3 star, the hydrogen lines of an F1 star, and the metal lines of an F2 star.[4] It is a sharp-lined, slowly rotating star[11] with a projected rotational velocity of 9.6 km/s[6] and is about 465 million years old.[7] The star has 1.69[7] times the mass of the Sun and three[1] times the Sun's radius. It is radiating 29[1] times the luminosity of the Sun from its photosphere at an effective temperature of 7,976 K.[7]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  3. Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey 5, Bibcode1999MSS...C05....0H. 
  4. 4.0 4.1 Abt, Helmut A. (January 2009), "MK Classifications of Spectroscopic Binaries", The Astrophysical Journal Supplement 180 (1): 117–118, doi:10.1088/0067-0049/180/1/117, Bibcode2009ApJS..180..117A. 
  5. 5.0 5.1 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. 
  6. 6.0 6.1 6.2 6.3 6.4 Carrier, F. et al. (August 2007), "A search for solar-like oscillations in the Am star HD 209625", Astronomy and Astrophysics 470 (3): 1009–1012, doi:10.1051/0004-6361:20067022, Bibcode2007A&A...470.1009C. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 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, Bibcode2015ApJ...804..146D. 
  8. Hui-Bon-Hoa, A. (June 2000), "Metal abundances of field A and Am stars", Astronomy and Astrophysics Supplement 144 (2): 203–209, doi:10.1051/aas:2000207, Bibcode2000A&AS..144..203H. 
  9. "32 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=32+Aqr. 
  10. Chupina, N. V. et al. (June 2006), "Kinematic structure of the corona of the Ursa Major flow found using proper motions and radial velocities of single stars", Astronomy and Astrophysics 451 (3): 909–916, doi:10.1051/0004-6361:20054009, Bibcode2006A&A...451..909C. 
  11. Kocer, D. et al. (July 1987), "Optical region elemental abundance analyses of B and A stars. VII - The metallic-lined star 32 Aquarii", Astronomy and Astrophysics Supplement Series 70 (1): 49–56, Bibcode1987A&AS...70...49K.