Lacaille 9352

From Wikipedia, the free encyclopedia
Jump to: navigation, search
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
Distance 10.68 ± 0.02 ly
(3.276 ± 0.008 pc)
Details
Mass 0.503 ± 0.025[3] M
Radius 0.459 ± 0.011[3] R
Luminosity (bolometric) 0.033[note 1] L
Temperature 3,626[3] K
Metallicity [Fe/H] −0.22 ± 0.09[6] 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.[7]

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[8] and is the closest star in the constellation Piscis Austrinus. The ChView simulation[9] shows that its closest neighbour is the EZ Aquarii triple star system at about 4.1 ly from Lacaille 9352.

Distance[edit]

Lacaille 9352 distance estimates

Source Parallax, mas Distance, pc Distance, ly Ref.
Woolley et al. (1970) 279 ± 16 3.58+0.22
−0.19
11.7+0.7
−0.6
[10]
Gliese & Jahreiß (1991) 284.3 ± 14.9 3.52+0.19
−0.18
11.5 ± 0.6 [11]
van Altena et al. (1995) 278.6 ± 8.6 3.59 ± 0.11 11.7 ± 0.4 [12]
Perryman et al. (1997) (Hipparcos) 303.90 ± 0.87 3.291 ± 0.009 10.732 ± 0.031 [13]
Perryman et al. (1997) (Tycho) (absents) [14]
van Leeuwen (2007) 305.26 ± 0.70 3.276+0.008
−0.007
10.685+0.025
−0.024
[15]
RECONS TOP100 (2012) 305.08 ± 0.70[note 2] 3.278 ± 0.008 10.691+0.025
−0.024
[16]

Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.

Properties[edit]

This star has the fourth highest known proper motion,[17] (which was first noticed by Benjamin Gould in 1881[18]) 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.[19] 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.[20]

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,[21] 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[edit]

Notes[edit]

  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.
  2. ^ Weighted parallax based on parallaxes from van Altena et al. (1995) and van Leeuwen (2007).

References[edit]

  1. ^ a b c d e f 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. ^ a b c d 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. ^ a b c d e f g h 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. ^ a b 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. ^ 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. 
  7. ^ "LACAILLE 9352 -- Pre-main sequence Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-01-20. 
  8. ^ Research Consortium on Nearby Stars. "The One Hundred Nearest Star Systems". Georgia State University. Retrieved 2010-01-20. 
  9. ^ "Solstation and ChView". Retrieved 2010-04-20. 
  10. ^ Woolley R.; Epps E. A.; Penston M. J.; Pocock S. B. (1970). "Woolley 887". Catalogue of stars within 25 parsecs of the Sun. Retrieved 2014-10-20. 
  11. ^ Gliese, W. and Jahreiß, H. (1991). "Gl 887". Preliminary Version of the Third Catalogue of Nearby Stars. Retrieved 2014-10-20. 
  12. ^ Van Altena W. F., Lee J. T., Hoffleit E. D. (1995). "GCTP 5584". The General Catalogue of Trigonometric Stellar Parallaxes, Fourth Edition. Retrieved 2014-10-20. 
  13. ^ Perryman et al. (1997). "HIP 114046". The Hipparcos and Tycho Catalogues. Retrieved 2014-10-20. 
  14. ^ Perryman et al. (1997). "HIP 114046". The Hipparcos and Tycho Catalogues. Retrieved 2014-10-20. 
  15. ^ van Leeuwen F. (2007). "HIP 114046". Validation of the new Hipparcos reduction. Retrieved 2014-10-20. 
  16. ^ "RECONS TOP100". THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars). 2012. Retrieved 2014-10-20. 
  17. ^ "High Proper Motion Stars in the Hipparcos Catalogue". European Space Agency. July 1, 2007. Retrieved 2010-01-20. 
  18. ^ 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. 
  19. ^ "ARICNS star page of Lacaille 9352". Astronomisches Rechen-Institut Heidelberg. Retrieved 2010-04-16. 
  20. ^ "Annotations on NAME LACAILLE 9352 object". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-04-16. 
  21. ^ Glindemann, Andreas; Paresce, Francesco. "Giant Eyes for the VLT Interferometer". European Southern Observatory. Retrieved 2010-01-20. 

External links[edit]