Astronomy:HD 24040

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Short description: Star in the constellation Taurus
HD 24040
Observation data
Equinox J2000.0]] (ICRS)
Constellation Taurus
Right ascension  03h 50m 22.9678s[1]
Declination +17° 28′ 34.9254″[1]
Apparent magnitude (V) 7.50[2]
Characteristics
Evolutionary stage Main sequence
Spectral type G2V[3]
B−V color index 0.653±0.003[2]
Astrometry
Radial velocity (Rv)−9.36±0.08[2] km/s
Proper motion (μ) RA: 113.433[1] mas/yr
Dec.: −251.101[1] mas/yr
Parallax (π)21.4719 ± 0.0241[1] mas
Distance151.9 ± 0.2 ly
(46.57 ± 0.05 pc)
Absolute magnitude (MV)4.16[2]
Details
Mass1.14±0.02[4] M
Radius1.28±0.03[4] R
Luminosity1.81±0.01[4] L
Surface gravity (log g)4.27±0.02[4] cgs
Temperature5,917±52[4] K
Metallicity [Fe/H]0.206±0.030[5] dex
Rotational velocity (v sin i)2.39±0.050[5] km/s
Age4.8±0.8[4] Gyr
Other designations
BD+17°638, HD 24040, HIP 17960, SAO 93630, LTT 11274, NLTT 11955[6]
Database references
SIMBADdata

HD 24040 is a star with two orbiting exoplanets in the equatorial constellation of Taurus. The star is too faint to be viewed with the naked eye, having an apparent visual magnitude of 7.50.[2] Based on parallax measurements, it is located at a distance of 152 light years. However, it is drifting closer to the Sun with a radial velocity of −9.4 km/s.[2]

This is a G-type main-sequence star with a stellar classification of G2V.[3] It is a metal-rich star with an age of around 4.8 billion years. The star has 14% more mass than the Sun and 128% of the Sun's radius. It is radiating 1.8 times the luminosity of the Sun from its photosphere at an effective temperature of 5,917 K.[4] The star is spinning slowly with a projected rotational velocity of 2.4 km/s.[5]

Planetary system

A long period planet was discovered in 2006 based on observations made at the W. M. Keck Observatory in Hawaii. However because the observations covered less than one complete orbit there were only weak constraints on the period and mass.[5] The first reliable orbit for HD 24040b was obtained by astronomers at Haute-Provence Observatory in 2012 who combined the keck measurements with ones from the SOPHIE and ELODIE spectrographs.[7] The most recent orbit published in 2015 added additional keck measurements and refined the orbital parameters.[8]

A linear trend in the radial velocities indicating a possible additional companion was detected at Haute-Provence Observatory and was also detected at keck but at a much smaller amplitude.[7][8] The linear trend was confirmed in 2021, together with the discovery of another planet, HD 24040 c.[9]

Planet c is in the habitable zone, with an ecc of <0.2, and may have a habitable moon.

The HD 24040 planetary system[8][9]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
c ≥0.201±0.027 MJ 1.3±0.021 515.4+2.2−2.5 0.11+0.120−0.079
b >4.10±0.12 MJ 4.637±0.067 3490±25 0.047±0.020

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 Sharma, Kaushal et al. (January 2020). "Application of convolutional neural networks for stellar spectral classification". Monthly Notices of the Royal Astronomical Society 491 (2): 2280–2300. doi:10.1093/mnras/stz3100. Bibcode2020MNRAS.491.2280S. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Bonfanti, A. et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics 575: A18. doi:10.1051/0004-6361/201424951. Bibcode2015A&A...575A..18B. http://www.aanda.org/articles/aa/full_html/2015/03/aa24951-14/aa24951-14.html. 
  5. 5.0 5.1 5.2 5.3 Wright, J. T. et al. (2007). "Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars". The Astrophysical Journal 657 (1): 533–545. doi:10.1086/510553. Bibcode2007ApJ...657..533W. 
  6. "HD 24040". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+24040. 
  7. 7.0 7.1 Boisse, Isabelle et al. (2012), "The SOPHIE search for northern extrasolar planets V. Follow-up of ELODIE candidates: Jupiter-analogs around Sun-like stars", Astronomy and Astrophysics 545: A55, doi:10.1051/0004-6361/201118419, Bibcode2012A&A...545A..55B 
  8. 8.0 8.1 8.2 Feng, Y. Katherina et al. (2015). "The California Planet Survey IV: A Planet Orbiting the Giant Star HD 145934 and Updates to Seven Systems with Long-period Planets". The Astrophysical Journal 800 (1): 22. doi:10.1088/0004-637X/800/1/22. Bibcode2015ApJ...800...22F. 
  9. 9.0 9.1 Rosenthal, Lee J. et al. (2021), "The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades", The Astrophysical Journal Supplement Series 255 (1): 8, doi:10.3847/1538-4365/abe23c, Bibcode2021ApJS..255....8R 

External links

Coordinates: Sky map 03h 50m 22.9681s, +17° 28′ 34.919″