HD 125612 is a binary star system with three exoplanetary companions[2][8] in the equatorial constellation of Virgo. It is too dim to be visible to the naked eye, having an apparent visual magnitude of 8.31.[2] The system is located at a distance of 188 light years from the Sun based on parallax measurements, but it is drifting closer with a radial velocity of −18 km/s.[1]

HD 125612
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Virgo
Right ascension 14h 20m 53.517665s[1]
Declination −17° 28′ 53.489700″[1]
Apparent magnitude (V) 8.31[2] / ?
Characteristics
Spectral type G3V[2] + M3- 4V[3]
Apparent magnitude (B) 8.938[4]
Apparent magnitude (J) 7.179±0.023[4]
Apparent magnitude (H) 6.950±0.059[4]
Apparent magnitude (K) 6.838±0.026[4]
B−V color index 0.628±0.018[4]
Astrometry
Radial velocity (Rv)−18.25±0.15[1] km/s
Proper motion (μ) RA: −60.260±0.034 mas/yr[1]
Dec.: −67.314±0.027 mas/yr[1]
Parallax (π)17.2897 ± 0.0279 mas[1]
Distance188.6 ± 0.3 ly
(57.84 ± 0.09 pc)
Absolute magnitude (MV)4.65[4]
Position (relative to HD 125612 A)[3]
ComponentHD 125612 B
Angular distance89.994±0.066
Position angle162.682±0.052°
Projected separation~4,750 AU
Details
Mass1.091±0.027 M[2]
1.133±0.025[5] M
Radius1.05±0.08[2] R
Luminosity1.09[2] L
Surface gravity (log g)4.41±0.05[2] cgs
Temperature5,900±18[2] K
Metallicity [Fe/H]0.23±0.014[2] dex
Rotational velocity (v sin i)3.2[6] km/s
Age1.351±1.127[5] Gyr
HD 125612 B
Mass0.184±0.012[3] M
Age1-5[3] Gyr
Other designations
BD−16˚ 3844, HD 125612, HIP 70123, SAO 158501, PPM 228650, GSC 06143-01696[7]
Database references
SIMBADdata
Exoplanet Archivedata

The yellow-hued primary component, designated HD 125612 A, is an ordinary G-type main-sequence star with a stellar classification of G3V,[2] which indicates it is generating energy through hydrogen fusion at its core. It is about 1.4[5] billion years old and is rich in heavy elements, having a 70% greater abundance of iron compared to the Sun. The star has 109% of the mass and 105% of the girth of the Sun. It is radiating 109% of the luminosity of the Sun from its photosphere at an effective temperature of 5,900 K.[2]

A red dwarf companion star, HD 125612 B, was detected in 2009 at a projected separation of 4750 AU. The possibility of a much closer companion to the primary star was also suggested, though this will need more observation to better define.[3]

Planetary system

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Diagram of the probable HD 125612 Star system.

There are three known exoplanets in orbit around HD 125612 A. The first was reported in 2007 and designated HD 125612 b, but it did not fully resolve the stellar velocity variations and it was clear there were other companions.[9] Two additional companions, HD 125612 c and d, were reported in 2009.[3] In 2022, the inclination and true mass of the outer planet HD 125612 d were measured via astrometry.[10]

The HD 125612 planetary system[11][10]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
c ≥0.055±0.01 MJ 0.0524±0.0031 4.15514±0.00026 0.049±0.038
b ≥3.1±0.4 MJ 1.372±0.083 557.04±0.35 0.4553±0.0055
d 7.178+0.932
−0.445
 MJ
3.982+0.159
−0.174
2822.7+15.0
−15.3
0.115±0.012 88.195+16.306
−15.980
°

See also

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References

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  1. ^ a b c d e f 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 f g h i j k l Lo Curto, G.; et al. (2015). "The HARPS search for southern extra-solar planets. XXII. Multiple planet systems from the HARPS volume limited sample". Astronomy and Astrophysics. 512. A48. arXiv:1411.7048. Bibcode:2010A&A...512A..48L. doi:10.1051/0004-6361/200913523.
  3. ^ a b c d e f Mugrauer, M.; Neuhäuser, R. (2009). "The multiplicity of exoplanet host stars New low-mass stellar companions of the exoplanet host stars HD 125612 and HD 212301". Astronomy and Astrophysics. 494 (1): 373–378. arXiv:0812.2561. Bibcode:2009A&A...494..373M. doi:10.1051/0004-6361:200810639. S2CID 15018915.
  4. ^ a b c d e f 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.
  5. ^ a b c Delgado Mena, E.; et al. (April 2019). "Abundance to age ratios in the HARPS-GTO sample with Gaia DR2. Chemical clocks for a range of [Fe/H]". Astronomy & Astrophysics. 624: 24. arXiv:1902.02127. Bibcode:2019A&A...624A..78D. doi:10.1051/0004-6361/201834783. S2CID 90259810. A78.
  6. ^ Costa Silva, A. R.; et al. (February 2020). "Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur". Astronomy & Astrophysics. 634: 10. arXiv:1912.08659. Bibcode:2020A&A...634A.136C. doi:10.1051/0004-6361/201936523. S2CID 209405391. A136.
  7. ^ "HD 125612". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-10-07.
  8. ^ Fischer, Debra A.; et al. (2007). "Five Intermediate-Period Planets from the N2K Sample". The Astrophysical Journal. 669 (2): 1336–1344. arXiv:0704.1191. Bibcode:2007ApJ...669.1336F. doi:10.1086/521869. S2CID 7774321.
  9. ^ Fischer, Debra A.; et al. (November 2007). "Five Intermediate-Period Planets from the N2K Sample". The Astrophysical Journal. 669 (2): 1336–1344. arXiv:0704.1191. Bibcode:2007ApJ...669.1336F. doi:10.1086/521869. S2CID 7774321.
  10. ^ 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.
  11. ^ Ment, Kristo; et al. (2018). "Radial Velocities from the N2K Project: Six New Cold Gas Giant Planets Orbiting HD 55696, HD 98736, HD 148164, HD 203473, and HD 211810". The Astronomical Journal. 156 (5). 213. arXiv:1809.01228. Bibcode:2018AJ....156..213M. doi:10.3847/1538-3881/aae1f5. S2CID 119243619.