Astronomy:HD 89744

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Short description: Star in the constellation Ursa Major
HD 89744
Observation data
{{#ifeq:J2000.0|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| Epoch J2000.0      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000.0}}
Constellation Ursa Major
A
Right ascension  10h 22m 10.5619s[1]
Declination +41° 13′ 46.310″[1]
Apparent magnitude (V) 5.73[2]
B
Right ascension  10h 22m 14.8721s[3]
Declination +41° 14′ 26.514″[3]
Apparent magnitude (V)
Characteristics
Evolutionary stage Main sequence
Spectral type F7V[4] or F8IV[5]
B−V color index 0.531±0.003[2]
Astrometry
A
Radial velocity (Rv)−4.35±0.12[2] km/s
Proper motion (μ) RA: −120.285(42)[1] mas/yr
Dec.: −138.171(50)[1] mas/yr
Parallax (π)25.9334 ± 0.0436[1] mas
Distance125.8 ± 0.2 ly
(38.56 ± 0.06 pc)
Absolute magnitude (MV)2.83[6]
B
Proper motion (μ) RA: −119.215(647) mas/yr
Dec.: −140.390(457) mas/yr
Parallax (π)26.0070 ± 0.4713[3] mas
Distance125 ± 2 ly
(38.5 ± 0.7 pc)
Details
A
Mass1.37±0.09[7] M
Radius2.16+0.06
−0.01
[8] R
Luminosity6.38±0.02[9] L
Surface gravity (log g)4.27±0.05[7] cgs
Temperature6,381±43[7] K
Metallicity [Fe/H]0.30±0.03[7] dex
Rotation~9 days[9]
Rotational velocity (v sin i)9.3[10] km/s
Age8.4[9] Gyr
B
Mass0.076[11] M
Other designations
BD+41°2076, GJ 9326, HD 89744, HIP 50786, HR 4067, WDS J10222+4114[12]
A: {{{names1}}}
B: {{{names2}}}
Database references
A
SIMBADdata
Exoplanet Archivedata
ARICNSdata
B
SIMBADdata

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.

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 astronomical unit|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]

The HD 89744 planetary system[21]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b >8.35±0.18 MJ 0.917±0.009 256.78±0.02 0.677±0.003
c (unconfirmed) >5.36±4.57 MJ 8.3±1.8 6,974±2,161 0.29±0.12

See also

References

  1. 1.0 1.1 1.2 1.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 3.2 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  4. 4.0 4.1 4.2 Scholz, R. -D. (March 2016). "Overlooked wide companions of nearby F stars". Astronomy & Astrophysics 587: 8. doi:10.1051/0004-6361/201527965. A51. Bibcode2016A&A...587A..51S. 
  5. 5.0 5.1 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. doi:10.1086/504637. Bibcode2006AJ....132..161G. 
  6. 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. Bibcode2000A&A...361..614P. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 Sousa, S. G. et al. (November 2018). "SWEET-Cat updated. New homogenous spectroscopic parameters". Astronomy & Astrophysics 620: 13. doi:10.1051/0004-6361/201833350. A58. Bibcode2018A&A...620A..58S. 
  8. 8.0 8.1 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  9. 9.0 9.1 9.2 9.3 9.4 Metcalfe, Travis S.; Egeland, Ricky (January 2019). "Understanding the Limitations of Gyrochronology for Old Field Stars". The Astrophysical Journal 871 (1): 6. doi:10.3847/1538-4357/aaf575. 39. Bibcode2019ApJ...871...39M. 
  10. 10.0 10.1 Morris, Brett M. et al. (September 2019). "Stellar Properties of Active G and K Stars: Exploring the Connection between Starspots and Chromospheric Activity". The Astronomical Journal 158 (3): 16. doi:10.3847/1538-3881/ab2e04. 101. Bibcode2019AJ....158..101M. 
  11. 11.0 11.1 11.2 Mugrauer, M. et al. (2005). "Four new wide binaries among exoplanet host stars". Astronomy and Astrophysics 440 (3): 1051–1060. doi:10.1051/0004-6361:20042297. Bibcode2005A&A...440.1051M. 
  12. "HD 89744". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+89744. 
  13. Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. 2. Sky Publishing Corporation and the European Space Agency. p. 617. ISBN 0-933346-83-2. 
  14. 14.0 14.1 Korzennik, Sylvain G. et al. (2000). "A High-Eccentricity Low-Mass Companion to HD 89744". The Astrophysical Journal Letters 533 (2): L147–L150. doi:10.1086/312611. PMID 10770711. Bibcode2000ApJ...533L.147K. 
  15. 15.0 15.1 Wright, J. T. (September 2004). "Do We Know of Any Maunder Minimum Stars?". The Astronomical Journal 128 (3): 1273–1278. doi:10.1086/423221. Bibcode2004AJ....128.1273W. 
  16. Lopez‐Santiago, J. et al. (2006). "The Nearest Young Moving Groups". The Astrophysical Journal 643 (2): 1160–1165. doi:10.1086/503183. Bibcode2006ApJ...643.1160L. 
  17. Schaefer, G. H. et al. (2018-05-07). "AB Dor Moving Group Stars Resolved with the CHARA Array". The Astrophysical Journal 858 (2). doi:10.3847/1538-4357/aaba71. Bibcode2018ApJ...858...71S. 
  18. 18.0 18.1 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. doi:10.1086/323134. Bibcode2001AJ....122.1989W. 
  19. Butler, R. P. et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal 646 (1): 505–522. doi:10.1086/504701. Bibcode2006ApJ...646..505B. 
  20. Wittenmyer, Robert A. et al. (2007). "Dynamical and Observational Constraints on Additional Planets in Highly Eccentric Planetary Systems". The Astronomical Journal 134 (3): 1276–1284. doi:10.1086/520880. Bibcode2007AJ....134.1276W. 
  21. 21.0 21.1 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. doi:10.1093/mnras/stz290. Bibcode2019MNRAS.484.5859W. 

Coordinates: Sky map 10h 11m 10.5621s, +41° 13′ 46.308″