HD 79940

Last updated
HD 79940
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Vela
Right ascension 09h 15m 45.07943s [1]
Declination −37° 24 47.3124 [1]
Apparent magnitude  (V)4.63 [2]
Characteristics
Spectral type F3/5V [3] or F5III [4] [5]
B−V color index 0.473±0.002 [2]
Astrometry
Radial velocity (Rv)+5.8±2.8 [2]  km/s
Proper motion (μ)RA: +14.128 [1]   mas/yr
Dec.: −8.111 [1]   mas/yr
Parallax (π)20.5985 ± 0.1895  mas [1]
Distance 158 ± 1  ly
(48.5 ± 0.4  pc)
Absolute magnitude  (MV)1.12 [2]
Details [6]
Mass 1.36 [6]   M
Radius 4.35+0.11
−0.19
[1]   R
Luminosity 28.427±0.305 [1]   L
Surface gravity (log g)3.26±0.14 [6]   cgs
Temperature 6,388+143
−76
[1]   K
Metallicity [Fe/H]0.20±0.15 [2]   dex
Rotational velocity (v sin i)117.2±5.9 [7]  km/s
Age 2.76 [6]   Gyr
Other designations
k Vel, CD−36 5505, GJ  339.3, GJ  9293, HD  79940, HIP  45448, HR  3684, SAO  200163, WDS J09158-3725A [8]
Database references
SIMBAD data

HD 79940 is a single [9] star in the southern constellation of Vela. It has the Bayer designation of k Velorum; HD 79940 is the identifier from the Henry Draper Catalogue . This star has a yellow-white hue and is faintly visible to the naked eye as a point light source with an apparent visual magnitude of 4.63. [2] It is located at a distance of approximately 158  light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +6 km/s. [2]

There has been some disagreement over the stellar classification of this star. In 1975, S. Maladora found a class of F5III, suggesting an evolved F-type star, [4] matching an earlier (1957) classification by A. de Vaucouleurs. [5] N. Houk assigned it a class of F3/5V in 1979, matching an F-type main-sequence star. [3] It has a high rate of spin with a projected rotational velocity of 117.2±5.9 km/s. [7] This may explain why it was incorrectly classified as a spectroscopic binary in 1972. [9]

There is a faint magnitude 14.50 companion at an angular separation of 11.3 along a position angle of 126° from the brighter star. This was discovered by T. J. J. See in 1897. [10]

Related Research Articles

Kappa1 Sculptoris is a binary star system in the southern constellation of Sculptor. It is faintly visible to the naked eye, with a combined apparent visual magnitude of +5.51. Based upon an annual parallax shift of 12.91 mas as measured from Earth, it is located roughly 250 light years from the Sun.

Epsilon Sextantis, Latinized from ε Sextantis, is a solitary, yellow-white hued star in the equatorial constellation of Sextans. With an apparent visual magnitude of 5.24, it is faintly visible to the naked eye on a dark night. The distance to this star, based upon an annual parallax shift of 16.86 mas, is about 193 light years. It is drifting further away from the Sun with a radial velocity of +15 km/s.

<span class="mw-page-title-main">Tau Virginis</span> Star in the constellation Virgo

Tau Virginis is a single star in the zodiac constellation Virgo. With an apparent visual magnitude of 4.28, it is faintly visible to the naked eye. The distance to Tau Virginis, based upon parallax measurements, is approximately 225 light years with a margin of error of ±3 light years.

20 Aquarii, abbreviated 20 Aqr, is a star in the constellation Aquarius. 20 Aquarii is the Flamsteed designation. It is a dim star with an apparent visual magnitude of 6.38. Based upon an annual parallax shift of 15.34 mas, it is located 213 light years away but is moving closer to the Earth with a heliocentric radial velocity of −23 km/s. The star is predicted to come to within 110 light-years in around 1.9 million years.

<span class="mw-page-title-main">Nu Caeli</span> Star in the constellation Caelum

Nu Caeli is a yellow-white hued star in the constellation Caelum. It has an apparent visual magnitude of 6.07, which indicates it is near the lower limit on brightness that is visible to the naked eye. According to the Bortle scale, the star can be viewed from dark suburban skies. Based upon an annual parallax shift of 20.3 mas as seen from Earth, this star is located 161 light years from the Sun.

HD 111968, also known by the Bayer designation n Centauri, is a single star in the southern constellation of Centaurus. It is a white-hued star that is faintly visible to the naked eye with an apparent visual magnitude of +4.25. The star is located at a distance of approximately 149 light years from the Sun based on parallax. The radial velocity of the star is poorly constrained, with an estimated value of 2.5 km/s.

HD 220105 is a star in the northern constellation of Andromeda, and a member of the Sirius supercluster. It lies near the lower limit of visibility to the naked eye at an apparent visual magnitude of 6.24, and can be a challenge to spot under normal viewing conditions. The star is located 238 light years away, based upon an annual parallax shift of 13.78 mas. It is moving closer to the Earth with a heliocentric radial velocity of −2 km/s.

HD 6114 is a visual binary star system in the northern constellation of Andromeda. With a combined apparent magnitude of 6.46, the star can only be seen with the naked eye by keen-eyed observers even on the best of nights. Based upon an annual parallax shift of 10.4 mas as seen from Earth's orbit, the system is located approximately 108 parsecs (350 ly) distant.

<span class="mw-page-title-main">HD 149989</span> Star in the constellation Ara

HD 149989 is a single, variable star in the southern constellation of Ara, located near the western constellation border with Norma. It has the variable star designation V872 Arae, while HD 149989 is the identifier from the Henry Draper Catalogue. This is a dim star near the lower limit of visibility to the naked eye with an apparent visual magnitude that fluctuates around 6.30. It is located at a distance of 167 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 46 km/s.

HD 90089 is a star located in the northern circumpolar constellation Camelopardalis. With an apparent magnitude of 5.25, it is faintly visible to the naked eye under ideal conditions. This star is located relatively close at a distance of 75 light years, but is drifting away at a rate of almost 8 km/s.

HD 201507, also designated HR 8095, is a white-hued star located in the equatorial constellation Equuleus. It has an apparent magnitude of 6.43, placing it near the limit for naked eye visibility. Parallax measurements place the object at a distance of 214 light years and it is currently drifting closer with a heliocentric radial velocity of −43 km/s.

HD 32309 is a single star in the southern constellation of Lepus. It has a blue-white hue and is visible to the naked eye with an apparent visual magnitude of 4.91. The distance to this object is 197 light years based on parallax. It is drifting further away from the Sun with a radial velocity of +24 km/s. This is a member of the Columba association of co-moving stars.

π2 Gruis, Latinised as Pi2 Gruis, is a binary star system in the southern constellation of Grus. It is faintly visible to the naked eye as a yellow-white hued star with an apparent visual magnitude of 5.622. Based upon an annual parallax shift of 25.1 mas as seen from the Earth, the system is located 130 light years from the Sun.

Sigma2 Gruis is a binary star system in the southern constellation of Grus. Its apparent visual magnitude is 5.86. The pair had an angular separation of 2.7 arc seconds along a position angle of 265°, as of 1991. Located around 215 ly (66 pc) distant, the white-hued primary component is an A-type main-sequence star of spectral type A1V, a star that is currently fusing its core hydrogen.

<span class="mw-page-title-main">TU Corvi</span> Star in the constellation Corvus

TU Corvi is a yellow-white hued star in the southern constellation of Corvus. It is a dimly visible to the naked eye with an apparent visual magnitude of 6.20. The distance to this star can be estimated from its annual parallax shift of 13.3 mas, yielding a range of about 246 light years. Based upon measured changes in its proper motion, it may be a close binary system.

53 Virginis is a single, yellow-white hued star in the zodiac constellation of Virgo. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.04. Based upon an annual parallax shift of 29.49±0.29 mas, it is located 111 light years away. The star is moving closer to the Sun with a heliocentric radial velocity of −12.7 km/s. It has a relatively high rate of proper motion, traversing the celestial sphere at the rate of 284±18 mas/yr along a position angle of 162.2°.

<span class="mw-page-title-main">Rho Octantis</span> High proper motion star in the constellation Octans

Rho Octantis, Latinized from ρ Octantis, is a star located in the southern circumpolar constellation Octans. With an apparent magnitude of 5.57, its faintly visible to the naked eye under ideal conditions. The star is located 215 light years away from the Solar System, but is drifting closer with a radial velocity of −11 km/s.

HD 196775 is a solitary star in the equatorial constellation Delphinus. It has an apparent magnitude of 5.98, allowing it to be faintly seen with the naked eye. The object is relatively far at a distance of 1,050 light years but is approaching the Solar System with a heliocentric radial velocity of −4.6 km/s. HD 196775 has a high peculiar velocity of 21.8+1.9
−4.1
 km/s
compared to neighboring stars, indicating that it may be a runaway star.

HD 208741, also known as HR 8380, is a yellowish-white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.91, making it faintly visible to the naked eye. Parallax measurements place it at a distance of 211 light years, and it is currently receding with a heliocentric radial velocity of 8 km/s.

<span class="mw-page-title-main">HD 36187</span> Star in the constellation of Columba

HD 36187, also known as HR 1835, is a solitary, bluish-white hued star located in the southern constellation Columba, the dove. It has an apparent magnitude of 5.55, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from the Gaia spacecraft, it is estimated to be 282 light years away from the Solar System. However, it is receding rapidly with a heliocentric radial velocity of 50 km/s. At its current distance, HD 36187's brightness is diminished by 0.21 magnitude due to interstellar dust.

References

  1. 1 2 3 4 5 6 7 8 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  2. 1 2 3 4 5 6 7 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv: 1108.4971 , Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID   119257644.
  3. 1 2 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
  4. 1 2 Malaroda, S. (August 1975), "Study of the F-type stars. I. MK spectral types.", Astronomical Journal, 80: 637–641, Bibcode:1975AJ.....80..637M, doi: 10.1086/111786 .
  5. 1 2 de Vaucouleurs, A. (1957). "Spectral types and luminosities of B, A and F southern stars". Monthly Notices of the Royal Astronomical Society. 117 (4): 449. Bibcode:1957MNRAS.117..449D. doi: 10.1093/mnras/117.4.449 .
  6. 1 2 3 4 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, arXiv: 1501.03154 , Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID   33401607.
  7. 1 2 Reiners, Ansgar (January 2006), "Rotation- and temperature-dependence of stellar latitudinal differential rotation", Astronomy and Astrophysics, 446 (1): 267–277, arXiv: astro-ph/0509399 , Bibcode:2006A&A...446..267R, doi:10.1051/0004-6361:20053911, S2CID   8642707
  8. "HD 79940". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-09-28.
  9. 1 2 Kunzli, M.; North, P. (January 1998), "Are metallic A-F giants evolved AM stars? Rotation and rate of binaries among giant F stars", Astronomy and Astrophysics Supplement, 127 (2): 277–294, arXiv: astro-ph/9710226 , Bibcode:1998A&AS..127..277K, doi:10.1051/aas:1998350, S2CID   7535170.
  10. Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi: 10.1086/323920 .