HD 149382

Last updated
HD 149382
Observation data
Epoch J2000       Equinox J2000
Constellation Ophiuchus
Right ascension 16h 34m 23.33337s [1]
Declination −04° 00′ 52.0301″ [1]
Apparent magnitude  (V)8.943 [2]
Characteristics
Spectral type B5 VI [3]
U−B color index −1.143 [2]
B−V color index −0.282 [2]
V−R color index −0.127 [2]
R−I color index −0.135 [2]
Astrometry
Radial velocity (Rv)+3 [4] km/s
Proper motion (μ)RA: −6.234 [1] mas/yr
Dec.: −5.780 [1] mas/yr
Parallax (π)13.2407±0.0567  mas [1]
Distance 246 ± 1  ly
(75.5 ± 0.3  pc)
Details
Mass 0.29 –0.53 [5]   M☉
Radius 0.143 [6]   R☉
Luminosity 25.2 [6]   L☉
Surface gravity (log g)5.80±0.05 [5]   cgs
Temperature 35,500±500 [5]   K
Metallicity [Fe/H]−1.30 [3]   dex
Rotational velocity (v sin i)4.9±1.4 [5]  km/s
Other designations
BD−03°3967, HD 149382, HIP 81145, SAO 141250 [7]
Database references
SIMBAD data

HD 149382 is a hot subdwarf star in the constellation of Ophiuchus with an apparent visual magnitude of 8.943. [2] This is too faint to be seen with the naked eye even under ideal conditions, although it can be viewed with a small telescope. [8] Based upon parallax measurements, this star is located at a distance of about 246 light-years (75.5 parsecs ) from the Earth.

This is the brightest known B-type subdwarf star with a stellar classification of B5 VI. It is generating energy through the thermonuclear fusion of helium at its core (triple-alpha process). [3] The effective temperature of the star's outer envelope is about 35,500 K, giving it the characteristic blue-white hue of a B-type star. Although only about one seventh the diameter of the Sun, it radiates about 25 times as much due to its high temperature. HD 149382 has a visual companion located at an angular separation of 1 arcsecond. [9]

In 2009, a substellar companion, perhaps even a superjovian planet, was announced orbiting the star. This candidate object was estimated to have 8 to 23 times the mass of Jupiter. [5] In 2011, this discovery was thrown into doubt when an independent team of astronomers were unable to confirm the detection. Their observations rule out a companion with a mass greater than Jupiter orbiting with a period of less than 28 days. [9]

See also

References

  1. 1 2 3 4 5 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  2. 1 2 3 4 5 6 Landolt, Arlo U. (May 2009). "UBVRI Photometric Standard Stars Around the Celestial Equator: Updates and Additions". The Astronomical Journal. 137 (5): 4186–4269. arXiv: 0904.0638 . Bibcode:2009AJ....137.4186L. doi:10.1088/0004-6256/137/5/4186. S2CID   118627330. See table II.
  3. 1 2 3 Cenarro, A. J.; et al. (January 2007). "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters". Monthly Notices of the Royal Astronomical Society . 374 (2): 664–690. arXiv: astro-ph/0611618 . Bibcode:2007MNRAS.374..664C. doi: 10.1111/j.1365-2966.2006.11196.x . S2CID   119428437.
  4. ↑ Wilson, Ralph Elmer (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Washington: Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
  5. 1 2 3 4 5 Geier, S.; et al. (September 2009). "Discovery of a Close Substellar Companion to the Hot Subdwarf Star HD 149382—The Decisive Influence of Substellar Objects on Late Stellar Evolution". The Astrophysical Journal Letters . 702 (1): L96 –L99. arXiv: 0908.1025 . Bibcode:2009ApJ...702L..96G. doi:10.1088/0004-637X/702/1/L96. S2CID   119282460.
  6. 1 2 Stassun, Keivan G.; et al. (September 2018). "The TESS Input Catalog and Candidate Target List". The Astronomical Journal. 156 (3): 102. arXiv: 1706.00495 . Bibcode:2018AJ....156..102S. doi: 10.3847/1538-3881/aad050 . ISSN   0004-6256.
  7. ↑ "HD 149382 -- Star". SIMBAD. Centre de Données astronomiques de Strasbourg . Retrieved 2010-10-06.
  8. ↑ Sherrod, P. Clay; Koed, Thomas L. (2003). A Complete Manual of Amateur Astronomy: Tools and Techniques for Astronomical Observations. Astronomy Series. Courier Dover Publications. p. 9. ISBN   0-486-42820-6.
  9. 1 2 Norris, Jackson M.; et al. (December 2011). "Non-detection of the Putative Substellar Companion to HD 149382". The Astrophysical Journal. 743 (1): 88. arXiv: 1110.1384 . Bibcode:2011ApJ...743...88N. doi:10.1088/0004-637X/743/1/88. S2CID   118337277.
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