L 97-12

From Wikipedia, the free encyclopedia
  (Redirected from Gliese 293)
Jump to: navigation, search

Coordinates: Sky map 07h 53m 08.15s, −67° 47′ 31.4″

L 97-12
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Volans
Right ascension 07h 53m 08.15s[1]
Declination −67° 47′ 31.4″[1]
Apparent magnitude (V) 13.96[2]
Characteristics
Spectral type DC8.8,[3] or DC10.3[4]
Apparent magnitude (B) 14.75[1]
Apparent magnitude (V) 13.96[2]
Apparent magnitude (RKC) 13.58[2]
Apparent magnitude (IKC) 13.20[2]
Apparent magnitude (J) 12.726 ± 0.023[1]
Apparent magnitude (H) 12.476 ± 0.026[1]
Apparent magnitude (KS) 12.362 ± 0.024[1]
Astrometry
Proper motion (μ) RA: 1462[2] mas/yr
Dec.: −1504[2] mas/yr
Parallax (π) 126.25 ± 1.34[2] mas
Distance 25.8 ± 0.3 ly
(7.92 ± 0.08 pc)
Absolute magnitude (MV) 14.47 ± 0.04[2]
Details
Mass 0.59 ± 0.01[2] M
Radius 0.0128[2][note 1] R
Surface gravity (log g) 8.00 ± 0.02[2] cgs
Temperature 5700 ± 90[2] K
Age 2.65 ± 0.10[2][note 2] Gyr
Other designations
Gliese 293, LHS 34, LFT 555, LTT 2981, L 97-12,[5] WD 0752-676, EGGR 56, 2MASS J07530814-6747314[1]
Database references
SIMBAD data

L 97-12 (or WD 0752-676, or LHS 34, or Gliese 293) is a nearby degenerate star (white dwarf), located in the constellation Volans, the single known component of the system.

Distance[edit]

Possibly, L 97-12 is the ninth closest white dwarf after Sirius B, Procyon B, van Maanen's star, Gliese 440, 40 Eridani B, Stein 2051 B, GJ 1221 and Gliese 223.2. (However, there is probability, that white dwarfs GJ 1087,[5] Gliese 518[5] and (with lesser probability) Gliese 915[2] may be located closer). Trigonometric parallax of L 97-12 was included in the YPC (Yale Parallax Catalog), and subsequently it was measured more precisely in CTIOPI (Cerro Tololo Inter-American Observatory (CTIO) Parallax Investigation) 0.9 m telescope program:

L 97-12 parallax measurements

Source Paper Parallax, mas Distance, pc Distance, ly Ref.
YPC van Altena et al., 1995 141.2 ± 8.4 7.08 ± 0.42 23.10 ± 1.37 [5]
CTIOPI 0.9 m TSN-21 (Subasavage et al., 2009) 126.25 ± 1.34 7.92 ± 0.08 25.83 ± 0.27 [2]

Physical parameters[edit]

The mass of L 97-12 is 0.59 ± 0.01 Solar masses,[2] and its surface gravity is 108.00 ± 0.02 cm·s−2,[2] or approximately 102 000 of Earth's, corresponding to a radius 8887 km, or 139% of Earth's.

L 97-12 has temperature 5700 ± 90 K,[2] almost like the Sun, and cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star) 2.65 ± 0.10 Gyr.[2] Despite it is classified as "white dwarf", it should appear yellow, not white, nearly the same color as the Sun.

Notes[edit]

  1. ^ From surface gravity and mass.
  2. ^ White dwarf cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star)

References[edit]

  1. ^ a b c d e f g "GJ 293 -- White Dwarf". Centre de Données astronomiques de Strasbourg. Retrieved 2011-10-30. 
  2. ^ a b c d e f g h i j k l m n o p q r s Subasavage, John P.; Jao; Henry; Bergeron; Dufour; Ianna; Costa; Mendez (2009). "THE SOLAR NEIGHBORHOOD. XXI. PARALLAX RESULTS FROM THE CTIOPI 0.9 m PROGRAM: 20 NEW MEMBERS OF THE 25 PARSEC WHITE DWARF SAMPLE". The Astronomical Journal 137: 4547–4560. Bibcode:2009AJ....134.4547S. doi:10.1088/0004-6256/137/6/4547. 
  3. ^ Holberg, J. B.; Sion; Oswalt; McCook; Foran; Subasavage (2008). "A NEW LOOK AT THE LOCAL WHITE DWARF POPULATION". The Astronomical Journal 135: 1225–1238. Bibcode:2008AJ....135.1225H. doi:10.1088/0004-6256/135/4/1225. 
  4. ^ Sion, Edward M.; Holberg; Oswalt; McCook; Wasatonic (2009). "THE WHITE DWARFS WITHIN 20 PARSECS OF THE SUN: KINEMATICS AND STATISTICS". The Astronomical Journal 138: 1681–1689. arXiv:0910.1288. Bibcode:2009AJ....138.1681S. doi:10.1088/0004-6256/138/6/1681. 
  5. ^ a b c d Yale Trigonometric Parallaxes, Fourth Edition (van Altena+ 1995)