HD 38529 (138 G. Orionis) is a binary star approximately 138 light-years away in the constellation of Orion.

HD 38529 A/B
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Orion
HD 38529 A
Right ascension 05h 46m 34.91314s[1]
Declination +01° 10′ 05.5029″[1]
Apparent magnitude (V) +5.94
HD 38529 B
Right ascension 05h 46m 19.37663s[2]
Declination +01° 12′ 47.2640″[2]
Apparent magnitude (V) +13.35
Characteristics
Spectral type G4IV / M3.0V
U−B color index ? / ?
B−V color index 0.773 / 0.46
Variable type none / ?
Astrometry
HD 38529 A
Radial velocity (Rv)30.19±0.12[1] km/s
Proper motion (μ) RA: −77.806±0.041 mas/yr[1]
Dec.: −141.363±0.038 mas/yr[1]
Parallax (π)23.5714 ± 0.0422 mas[1]
Distance138.4 ± 0.2 ly
(42.42 ± 0.08 pc)
Absolute magnitude (MV)+2.81
HD 38529 B
Radial velocity (Rv)30.94±0.43[2] km/s
Proper motion (μ) RA: −78.612±0.017 mas/yr[2]
Dec.: −142.084±0.013 mas/yr[2]
Parallax (π)23.7139 ± 0.0168 mas[2]
Distance137.54 ± 0.10 ly
(42.17 ± 0.03 pc)
Absolute magnitude (MV)+10.23
Details[3][4]
HD 38529 A
Mass1.479±0.037 M
Radius2.678±0.026 R
Luminosity6.16±0.15 L
Surface gravity (log g)3.83±0.06 cgs
Temperature5619±44 K
Metallicity [Fe/H]0.38±0.03 dex
Rotational velocity (v sin i)3.20±0.50 km/s
Age3.07±0.39 Gyr
Other designations
RAG 1, WDS J05466+0110AB[5]
HD 38529 A: BD+01°1126, HIP 27253, HR 1988, WDS J05466+0110A[6]
HD 38529 B: WDS J05466+0110B, LP 598-99, 2MASS J05461937+0112471[7]
Database references
SIMBADdata

HD 38529 A

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HD 38529 A is a yellow subgiant star, which has also been classified as a main sequence dwarf of spectral type G4V. It is about 40% more massive than the Sun. Two substellar companions are known in orbit around this star, including one with a mass near the deuterium fusion limit that is often used as the dividing line between giant planets and brown dwarfs. There is a debris disk located at least 86 astronomical units from the star.[8] Its orbit is probably mildly misaligned with the planetary orbits, by 21−45°.[9]

Planetary system

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In 2002, the planet HD 38529 b was discovered orbiting the star HD 38529 A by Debra Fischer and collaborators who detected it using the doppler spectroscopy technique.[10] It has a mass 78% that of Jupiter and orbits very close to the star, just beyond the distance limit for hot Jupiters. One year later, a massive superjovian HD 38529 c was found orbiting at 3.68 AU with a minimum mass of 12.7 Jupiter masses.[11] Astrometric measurements from the Hipparcos satellite gave a best fit inclination of 160° and a true mass 37 times that of Jupiter, turning this planet into a brown dwarf.[12] Further study of the system using Hubble Space Telescope astrometry revised the mass of HD 38529 c downwards to 17.7 Jupiter masses and suggested the presence of an additional planet, orbiting in the gap between HD 38529 b and c.[13] The possible third planet was refuted after additional radial velocity measurements were collected.[3] A 2022 study estimated an even lower mass of 10.4 Jupiter masses for HD 38529 c. The authors state that their mass estimate is consistent with previous estimates, but with higher precision.[14]

The HD 38529 A planetary system[3][14]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b ≥0.8047±0.0139 MJ 0.1278±0.0006 14.30978±0.00033 0.259±0.016
c 10.380+1.025
−0.884
 MJ
3.226+0.131
−0.144
2127.6+1.5
−1.6
0.357±0.005 104.559+6.393
−8.722
°
Debris disk >86 AU

HD 38529 B

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HD 38529 B is a common proper motion stellar companion to HD 38529 A at a projected distance of about ~12000 Astronomical units. The star is a red dwarf of spectral type M3.0V.[15] Wide binary stars such as HD 38529 AB have been shown to be vulnerable to disruption by galactic tides and perturbations by passing stars.[16]

See also

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References

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  1. ^ a b c d e 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. ^ a b c d e 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.
  3. ^ a b c Henry, Gregory W.; et al. (2013). "Host Star Properties and Transit Exclusion for the HD 38529 Planetary System". The Astrophysical Journal. 768 (2). 155. arXiv:1303.4735. Bibcode:2013ApJ...768..155H. doi:10.1088/0004-637X/768/2/155.
  4. ^ Ball, Warrick H.; Chaplin, William J.; Nielsen, Martin B.; González-Cuesta, Lucia; Mathur, Savita; Santos, Ângela R G.; García, Rafael; Buzasi, Derek; Mosser, Benoît; Deal, Morgan; Stokholm, Amalie; Mosumgaard, Jakob Rørsted; Silva Aguirre, Victor; Nsamba, Benard; Campante, Tiago; Cunha, Margarida S.; Ong, Joel; Basu, Sarbani; Örtel, Sibel; Çelik Orhan, Z.; Yıldız, Mutlu; Stassun, Keivan; Kane, Stephen R.; Huber, Daniel (2020), "Robust asteroseismic properties of the bright planet host HD 38529", Monthly Notices of the Royal Astronomical Society, 499 (4): 6084–6093, arXiv:2010.07323, Bibcode:2020MNRAS.499.6084B, doi:10.1093/mnras/staa3190, S2CID 222378164
  5. ^ "WDS J05466+0110AB". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-07.
  6. ^ "HD 38529". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-09.
  7. ^ "HD 38529 B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-09.
  8. ^ Hillenbrand, Lynne A.; et al. (2008). "The Complete Census of 70 μm-bright Debris Disks within "the Formation and Evolution of Planetary Systems" Spitzer Legacy Survey of Sun-like Stars". The Astrophysical Journal. 677 (1): 630–656. arXiv:0801.0163. Bibcode:2008ApJ...677..630H. doi:10.1086/529027.
  9. ^ Xuan, Jerry W.; Kennedy, Grant M.; Wyatt, Mark C.; Yelverton, Ben (2020), "Mutual inclinations between giant planets and their debris discs in HD 113337 and HD 38529", Monthly Notices of the Royal Astronomical Society, 499 (4): 5059–5074, arXiv:2010.02961, Bibcode:2020MNRAS.499.5059X, doi:10.1093/mnras/staa3155, S2CID 222177269
  10. ^ Fischer, Debra A.; et al. (2001). "Planetary Companions to HD 12661, HD 92788, and HD 38529 and Variations in Keplerian Residuals of Extrasolar Planets". The Astrophysical Journal. 551 (2): 1107–1118. Bibcode:2001ApJ...551.1107F. doi:10.1086/320224.
  11. ^ Fischer, Debra A.; et al. (2003). "A Planetary Companion to HD 40979 and Additional Planets Orbiting HD 12661 and HD 38529". The Astrophysical Journal. 586 (2): 1394–1408. Bibcode:2003ApJ...586.1394F. doi:10.1086/367889.
  12. ^ Reffert, S.; Quirrenbach, A. (2006). "Hipparcos astrometric orbits for two brown dwarf companions: HD 38529 and HD 168443". Astronomy and Astrophysics. 449 (2): 699–702. Bibcode:2006A&A...449..699R. doi:10.1051/0004-6361:20054611. hdl:1887/7483.
  13. ^ Benedict, G. Fritz; et al. (2010). "The Mass of HD 38529c from Hubble Space Telescope Astrometry and High-precision Radial Velocities". The Astronomical Journal. 139 (5): 1844–1856. arXiv:1003.0421. Bibcode:2010AJ....139.1844B. doi:10.1088/0004-6256/139/5/1844.
  14. ^ a b Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (21): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID 251864022.
  15. ^ Raghavan, Deepak; et al. (2006). "Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems". The Astrophysical Journal. 646 (1): 523–542. arXiv:astro-ph/0603836. Bibcode:2006ApJ...646..523R. doi:10.1086/504823.
  16. ^ Correa-Otto, J. A.; Gil-Hutton, R. A. (2017). "Galactic perturbations on the population of wide binary stars with exoplanets". Astronomy and Astrophysics. 608. A116. arXiv:1710.00766. Bibcode:2017A&A...608A.116C. doi:10.1051/0004-6361/201731229. hdl:11336/41265.
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