Astronomy:19 Aquarii

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Short description: White-hued hydrogen-burning star in the constellation Aquarius
19 Aquarii
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquarius[1]
Right ascension  21h 25m 13.01629s[2]
Declination −09° 44′ 54.7923″[2]
Apparent magnitude (V) +5.713[3]
Characteristics
Evolutionary stage main sequence[4]
Spectral type A8V[5]
B−V color index +0.20[6]
Astrometry
Radial velocity (Rv)−20.6±1.8[7] km/s
Proper motion (μ) RA: +25.943[2] mas/yr
Dec.: −167.548[2] mas/yr
Parallax (π)12.5593 ± 0.1676[2] mas
Distance260 ± 3 ly
(80 ± 1 pc)
Absolute magnitude (MV)0.90[1]
Details
Mass1.86[8] M☉
Radius2.76+0.18
−0.16[2] R☉
Luminosity26.1+0.4
−0.4[2] L☉
Surface gravity (log g)4.13[8] cgs
Temperature8,078±275[8] K
Rotational velocity (v sin i)102[9] km/s
Age788[8] Myr
Other designations
19 Aqr, BD−10°5668, HD 203875, HIP 105761, HR 8195, SAO 145382[10]
Database references
SIMBADdata

19 Aquarii is a star in the zodiac constellation of Aquarius. With an apparent magnitude of about 5.7,[3] the star is barely visible to the naked eye as a white-hued star (see Bortle scale). Parallax estimates put it at a distance of about 260 light years away from the Sun.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[7]

This object is an A-type main-sequence star with a stellar classification of A8V.[5] It is around 788[8] million years old with a fairly fast rotation rate, as its projected rotational velocity is about 155 km/s,[9] so it must be rotating at least that fast. It has 1.86[8] times the mass of the Sun and 2.76[2] times the Sun's radius. 19 Aquarii is radiating 26[2] times the luminosity of the Sun from its photosphere at an effective temperature of 8,078 K.[8] Eggen has this star flagged as a blue straggler and a member of the HR 1614 supercluster.[11]

References

  1. ↑ 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A  XHIP record for this object at VizieR.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 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. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  3. ↑ 3.0 3.1 Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode: 2000A&A...355L..27H. 
  4. ↑ Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode: 2012A&A...537A.120Z. 
  5. ↑ 5.0 5.1 Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5". Michigan Spectral Survey 5: 0. Bibcode: 1999MSS...C05....0H. 
  6. ↑ Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99. Bibcode: 1966CoLPL...4...99J. 
  7. ↑ 7.0 7.1 Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode: 2006AstL...32..759G. 
  8. ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 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. Bibcode: 2015ApJ...804..146D. 
  9. ↑ 9.0 9.1 Royer, F.; Zorec, J.; Gómez, A. E. (2007). "Rotational velocities of A-type stars". Astronomy and Astrophysics 463 (2): 671. doi:10.1051/0004-6361:20065224. Bibcode: 2007A&A...463..671R. 
  10. ↑ "* 19 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+19+Aqr. 
  11. ↑ Eggen, Olin J. (October 1996). "Star Streams and Galactic Structure". Astronomical Journal 112: 1595. doi:10.1086/118126. Bibcode: 1996AJ....112.1595E. 

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