Lacaille 9352

Lacaille 9352
Observation data
Epoch J2000      Equinox J2000
Constellation Piscis Austrinus
Right ascension 23h 05m 52.03604s[1]
Declination −35° 51′ 11.0475″[1]
Apparent magnitude (V) 7.34[2]
Characteristics
Spectral type M0.5V[3]
U−B color index +1.18[2]
B−V color index +1.50[2]
Variable type Suspected[4]
Astrometry
Radial velocity (Rv)+9.7[5] km/s
Proper motion (μ) RA: +6,768.20[1] mas/yr
Dec.: +1,327.52[1] mas/yr
Parallax (π)305.26 ± 0.70[1] mas
Distance10.68 ± 0.02 ly
(3.276 ± 0.008 pc)
Absolute magnitude (MV)9.8[6]
Details
Mass0.503 ± 0.025[3] M☉
Radius0.459 ± 0.011[3] R☉
Luminosity (bolometric)0.033[note 1] L☉
Temperature3,626[3] K
Metallicity [Fe/H]−0.22 ± 0.09[7] dex
Rotational velocity (v sin i)1[5] km/s
Other designations
HD 217987, CD -36°15693, GCTP 5584, GJ 887, LHS 70, SAO 214301, LTT 9348, LFT 1758, Cordoba 31353, NSV 14420, HIP 114046, UGPMF 591.[8]
Database references
SIMBADdata
ARICNSdata

Lacaille 9352 (Lac 9352) is a star in the southern constellation of Piscis Austrinus. With an apparent visual magnitude of 7.34,[2] this star is too faint to be viewed with the naked eye even under excellent seeing conditions. Parallax measurements place it at a distance of about 10.74 light-years (3.29 parsecs) from Earth.[1] It is the eleventh closest star system to the Solar System[9] and is the closest star in the constellation Piscis Austrinus. The ChView simulation[10] shows that its closest neighbour is the EZ Aquarii triple star system at about 4.1 ly from Lacaille 9352.

Properties

This star has the fourth highest known proper motion,[11] (which was first noticed by Benjamin Gould in 1881[12]) moving a total of 6.9 arcseconds per year. However, this is still a very small movement overall, as there are 3,600 arcseconds in a degree of arc. The space velocity components of this star are (U, V, W) = (−93.9, −14.1, −51.4) km/s.[13] If the radial velocity (Vr) equals +9.7 km/s then about 2,700 years ago Lacaille 9352 was at its minimal distance of approximately 10.63 ly (3.26 pc) from the Sun.[14]

The spectrum of Lacaille 9352 places it at a stellar classification of M0.5V,[3] indicating it is a type of main sequence star known as a red dwarf. This was the first red dwarf star to have its angular diameter measured,[15] with the physical diameter being about 46% of the Sun's radius.[3] It has around half the mass of the Sun[3] and the outer envelope has an effective temperature of about 3,626 K.[3]

See also

Notes

  1. ↑ From L=4πR2σTeff4, where L is the luminosity, R is the radius, Teff is the effective surface temperature and σ is the Stefan–Boltzmann constant.

References

  1. 1 2 3 4 5 6 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
  2. 1 2 3 4 Cousins, A. W. J. (1973). "UBV photometry of some southern stars". Monthly Notes of the Astronomical Society of Southern Africa 32: 11. Bibcode:1973MNSSA..32...11C.
  3. 1 2 3 4 5 6 7 8 Demory, B.-O.; et al. (October 2009), "Mass-radius relation of low and very low-mass stars revisited with the VLTI", Astronomy and Astrophysics 505 (1): 205–215, arXiv:0906.0602, Bibcode:2009A&A...505..205D, doi:10.1051/0004-6361/200911976
  4. ↑ Micela, G.; Pye, J.; Sciortino, S. (April 1997). "Coronal properties of nearby old disk and halo dM stars". Astronomy and Astrophysics 320: 865–877. Bibcode:1997A&A...320..865M.
  5. 1 2 Torres, C. A. O. (December 2006). "Search for associations containing young stars (SACY). I. Sample and searching method". Astronomy and Astrophysics 460 (3): 695–708. arXiv:astro-ph/0609258. Bibcode:2006A&A...460..695T. doi:10.1051/0004-6361:20065602.
  6. ↑ Murdin, Paul, ed. (November 2000). "Lacaille 9352". Encyclopedia of Astronomy and Astrophysics. Bristol: Institute of Physics Publishing. Bibcode:2000eaa..bookE5158. doi:10.1888/0333750888/5158. ISBN 0333750888. absolute magnitude is 9.8
  7. ↑ López-Morales, Mercedes (May 2007). "On the Correlation between the Magnetic Activity Levels, Metallicities, and Radii of Low-Mass Stars". The Astrophysical Journal 660 (1): 732–739. arXiv:astro-ph/0701702. Bibcode:2007ApJ...660..732L. doi:10.1086/513142.
  8. ↑ "LACAILLE 9352 -- Pre-main sequence Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-01-20.
  9. ↑ Research Consortium on Nearby Stars. "The One Hundred Nearest Star Systems". Georgia State University. Retrieved 2010-01-20.
  10. ↑ "Solstation and ChView". Retrieved 2010-04-20.
  11. ↑ "High Proper Motion Stars in the Hipparcos Catalogue". European Space Agency. July 1, 2007. Retrieved 2010-01-20.
  12. ↑ Gould, B. A. (1881). "Corrigenda in the Uranometria Argentina. Star with large proper motion". Astronomische Nachrichten 100: 7–10. Bibcode:1881AN....100....7G. doi:10.1002/asna.18811000104.
  13. ↑ "ARICNS star page of Lacaille 9352". Astronomisches Rechen-Institut Heidelberg. Retrieved 2010-04-16.
  14. ↑ "Annotations on NAME LACAILLE 9352 object". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-04-16.
  15. ↑ Glindemann, Andreas; Paresce, Francesco. "Giant Eyes for the VLT Interferometer". European Southern Observatory. Retrieved 2010-01-20.

External links

This article is issued from Wikipedia - version of the Monday, October 05, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.