HD_89744

HD 89744

HD 89744

Star in the constellation Ursa Major


HD 89744 is a star in the northern circumpolar constellation of Ursa Major, positioned about 0.4° due south of the bright star Tania Australis (μ UMa).[13] This object has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.73.[2] The distance to this star has been measured using the parallax method, which locates it 126 light years from the Sun. It is drifting closer with a radial velocity of −4.4 km/s.[2] There are two known exoplanets orbiting this star.

Quick Facts Observation data Epoch J2000.0 Equinox J2000.0, Apparent magnitude (V) ...

At various times the star HD 89744 has been assigned a stellar classification of F7V,[4][14] F7IV-V,[15] and F8IV,[5][2] suggesting it is an F-type main-sequence star that is evolving onto the subgiant branch. It is ~8.4[9] billion years old with an inactive chromosphere[15] and is spinning with a projected rotational velocity of 9.3 km/s.[10] The star is 2.16[8] times the size of the Sun with 1.4[7] times the Sun's radius. It is a high metallicity star, showing a greater abundance of heavier elements than in the Sun. The star is radiating 6.4[9] times the luminosity of the Sun from its photosphere at an effective temperature of 6,381 K.[7]

This star was identified as a member of the AB Doradus moving group by J. López-Santiago and collaborators in 2006.[16] It was later shown that its evolutionary state is incompatible with membership.[17]

In 2001, a faint co-moving companion was identified at an angular separation of 63.1 from the primary.[18] This is equivalent to a linear projected separation of 2,456 AU (0.04 ly).[11] The companion, designated component B, is an L-class (~L0.5)[4] brown dwarf[18] with a mass of ~0.076 M.[11]

Planetary system

In April 2000, a planet was discovered using radial velocity measurements taken at Fred Lawrence Whipple Observatory and Lick Observatory.[14] The orbital parameters were updated in 2006 and 2007 using additional measurements.[19][20] A second planet with a much longer period was discovered in 2019.[21]

More information Companion (in order from star), Mass ...

See also


References

  1. 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. 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. Scholz, R. -D. (March 2016). "Overlooked wide companions of nearby F stars". Astronomy & Astrophysics. 587: 8. arXiv:1601.01896. Bibcode:2016A&A...587A..51S. doi:10.1051/0004-6361/201527965. S2CID 118348424. A51.
  4. Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
  5. Pizzolato, N.; et al. (September 2000). "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases". Astronomy and Astrophysics. 361: 614–628. Bibcode:2000A&A...361..614P.
  6. Sousa, S. G.; et al. (November 2018). "SWEET-Cat updated. New homogenous spectroscopic parameters". Astronomy & Astrophysics. 620: 13. arXiv:1810.08108. Bibcode:2018A&A...620A..58S. doi:10.1051/0004-6361/201833350. S2CID 119374557. A58.
  7. Metcalfe, Travis S.; Egeland, Ricky (January 2019). "Understanding the Limitations of Gyrochronology for Old Field Stars". The Astrophysical Journal. 871 (1): 6. arXiv:1811.11905. Bibcode:2019ApJ...871...39M. doi:10.3847/1538-4357/aaf575. S2CID 119405127. 39.
  8. Mugrauer, M.; et al. (2005). "Four new wide binaries among exoplanet host stars". Astronomy and Astrophysics. 440 (3): 1051–1060. arXiv:astro-ph/0507101. Bibcode:2005A&A...440.1051M. doi:10.1051/0004-6361:20042297.
  9. Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 2. Sky Publishing Corporation and the European Space Agency. p. 617. ISBN 0-933346-83-2.
  10. Korzennik, Sylvain G.; et al. (2000). "A High-Eccentricity Low-Mass Companion to HD 89744". The Astrophysical Journal Letters. 533 (2): L147–L150. arXiv:astro-ph/0003045. Bibcode:2000ApJ...533L.147K. doi:10.1086/312611. PMID 10770711.
  11. Wright, J. T. (September 2004). "Do We Know of Any Maunder Minimum Stars?". The Astronomical Journal. 128 (3): 1273–1278. arXiv:astro-ph/0406338. Bibcode:2004AJ....128.1273W. doi:10.1086/423221. S2CID 118975831.
  12. Lopez‐Santiago, J.; et al. (2006). "The Nearest Young Moving Groups". The Astrophysical Journal. 643 (2): 1160–1165. arXiv:astro-ph/0601573. Bibcode:2006ApJ...643.1160L. doi:10.1086/503183.
  13. Schaefer, G. H.; et al. (2018-05-07). "AB Dor Moving Group Stars Resolved with the CHARA Array". The Astrophysical Journal. 858 (2) 71. Bibcode:2018ApJ...858...71S. doi:10.3847/1538-4357/aaba71.
  14. Wilson, J. C.; et al. (October 2001). "Three Wide-Separation L Dwarf Companions from the Two Micron All Sky Survey: Gliese 337C, Gliese 618.1B, and HD 89744B". The Astronomical Journal. 122 (4): 1989–2000. arXiv:astro-ph/0108424. Bibcode:2001AJ....122.1989W. doi:10.1086/323134. S2CID 17789028.
  15. Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv:astro-ph/0607493. Bibcode:2006ApJ...646..505B. doi:10.1086/504701.
  16. Wittenmyer, Robert A.; et al. (2019). "Truly eccentric – I. Revisiting eight single-eccentric planetary systems". Monthly Notices of the Royal Astronomical Society. 484 (4): 5859–5867. arXiv:1901.08471. Bibcode:2019MNRAS.484.5859W. doi:10.1093/mnras/stz290.

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