19 Aquarii

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19 Aquarii
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 21h 25m 13.02688s[1]
Declination −09° 44′ 54.7897″[1]
Apparent magnitude (V) +5.713[2]
Spectral type A8V[3]
B−V color index +0.20[4]
Radial velocity (Rv)−20.60 ± 1.8[5] km/s
Proper motion (μ) RA: 16.42[1] mas/yr
Dec.: −169.81[1] mas/yr
Parallax (π)10.89 ± 0.63[1] mas
Distance300 ± 20 ly
(92 ± 5 pc)
Rotational velocity (v sin i)102[6] km/s
Other designations
19 Aqr, BD−10° 5668, HD 203875, HIP 105761, HR 8195, SAO 145382[7]
Database references

19 Aquarii is a star in the constellation of Aquarius. With an apparent magnitude of about 5.7,[2] the star is barely visible to the naked eye (see Bortle scale). Parallax estimates made by the Hipparcos spacecraft put it at a distance of about 300 light years (92 parsecs) away from the Earth.[1]

19 Aquarii has a spectral type of A8V,[3] meaning it is an A-type main-sequence star. These types of stars are bluish-white colored, and have effective temperatures between 7100 and 11500 K.[8] It rotates fairly fast, as its projected rotational velocity is about 155 km/s,[6] so it must be rotating at least that fast.


  1. ^ a b c d e f van Leeuwen, F.; et al. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Archived from the original on 2016-04-02. 
  2. ^ a b Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. 
  3. ^ a b 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. 
  4. ^ Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99. Bibcode:1966CoLPL...4...99J. 
  5. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053Freely accessible. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. 
  6. ^ a b Royer, F.; Zorec, J.; Gómez, A. E. (2007). "Rotational velocities of A-type stars". Astronomy and Astrophysics. 463 (2): 671. arXiv:astro-ph/0610785Freely accessible. Bibcode:2007A&A...463..671R. doi:10.1051/0004-6361:20065224. 
  7. ^ "* 19 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 22 March 2017. 
  8. ^ Adelman, Saul J. (2004). "The physical properties of normal A stars". Proceedings of the International Astronomical Union. 2004: 1. Bibcode:2004IAUS..224....1A. doi:10.1017/S1743921304004314.