HD 154088

HD 154088
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ophiuchus
Right ascension 17h 04m 27.84s ± 5.62[1]
Declination −28° 34′ 57.64″ ± 3.16[1]
Apparent magnitude (V) 6.7258 ± 0.005[1]
Characteristics
Spectral type K0V
B−V color index 0.814 ± 0.034[1]
Astrometry
Radial velocity (Rv)14.2972 ± 0.0003[2] km/s
Proper motion (μ) RA: 83.76 ± 0.64[1] mas/yr
Dec.: -268.69 ± 0.36[1] mas/yr
Parallax (π)56.06 ± 0.50 mas[1]
Distance58.2 ± 0.5 ly
(17.8 ± 0.2 pc)
Absolute magnitude (MV)5.47 ± 0.02
Details
Mass0.97 ± 0.05[3] M☉
Radius0.95 ± 0.03[4] R☉
Luminosity0.68 +0.06
−0.05 (log -0.169 ± 0.033)[5] L☉
Surface gravity (log g)4.40 ± 0.11[3] cgs
Temperature5423 ± 51[3] K
Metallicity [Fe/H]0.31 ± 0.03[3] dex
Rotation42.6 ± 4.4[6]
Rotational velocity (v sin i)1.9 ± 0.5[5] km/s
Age3 - 8[3] Gyr
Other designations
CD−28° 12769, GJ 652, HIP 83541, SAO 184990
Database references
SIMBADdata

HD 154088 is a seventh magnitude metal-rich K-type main sequence star that lies approximately 58 light-years away in the constellation of Ophiuchus. The star is orbited by a hot Super-Earth.

Properties

The position of HD 154088 on the Hertzsprung-Russell diagram.

HD 154088 is a modestly bright star that lies at the bottom of Ophiuchus, near to the border with Scorpius and near to the plane of the Milky Way. The star was recognised as a high proper motion star during the last century, and early Earth-based parallax measurements such as that of the Gliese Catalogue of Nearby Stars indicated a distance of about 50 light-years.

The star has a spectral type of K0V, indicating that it is a main sequence star that is about 350 degrees cooler than the Sun. On the Hertzsprung-Russell diagram (left), the star lies slightly above the main sequence. This is because the star is very metal-rich; with an Fe/H of 0.3 dex the star has about twice the solar abundance of iron, which makes HD 154088 fall into the somewhat vague group of super metal-rich (SMR) stars. The giant planet occurrence rate of Fe/H = 0.3 stars is on the order of 30%, but HD 154088 is not currently known to host any giant planets.

HD 154088 has a pronounced magnetic field.[3] It also has a magnetic cycle similar to the Sun,[6] though its length is not well constrained.

The survey in 2015 have ruled out the existence of any additional stellar companions at projected distances from 8 to 119 astronomical units.[7]

Planetary system

A planet orbiting HD 154088 discovered with the HARPS spectrograph was announced in September 2011. With a minimum mass of 6 Earth masses, the companion falls into the regime of Super-Earths.

The HD 154088 planetary system[2]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b ≥6.15 ± 0.86 M🜨 0.1316 ± 0.0021 18.596 ± 0.021 0.38 ± 0.15 — —

HD 154088 is also being observed under the Keck Eta-Earth radial velocity survey.[8] HD 154088 b is a close match for planet candidate 1 (orbital period = 18.1 days, minimum mass = 6.5 M🜨), so they may be the same detection. The planet existence was finally confirmed in 2021.[9]

References

  1. ^ a b c d e f g van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  2. ^ a b Mayor, M.; et al. (2011). "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets". arXiv:1109.2497. Bibcode:2011arXiv1109.2497M. {{cite journal}}: Cite journal requires |journal= (help)
  3. ^ a b c d e f Fossati, L.; et al. (2013). "Detection of a magnetic field in three old and inactive solar-like planet-hosting stars". Astronomy. 551: A85. arXiv:1302.0879. Bibcode:2013A&A...551A..85F. doi:10.1051/0004-6361/201220997. S2CID 53377473.
  4. ^ Takeda, Genya; et al. (2007). "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog". The Astrophysical Journal Supplement Series. 168 (2): 297–318. arXiv:astro-ph/0607235. Bibcode:2007ApJS..168..297T. doi:10.1086/509763. S2CID 18775378.
  5. ^ a b Valenti, J. A.; Fischer, D. A. (2005). "Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs". The Astrophysical Journal Supplement Series. 159 (1): 141–166. Bibcode:2005ApJS..159..141V. doi:10.1086/430500.
  6. ^ a b Lovis, C.; et al. (2011). "The HARPS search for southern extra-solar planets. XXXI. Magnetic activity cycles in solar-type stars: statistics and impact on precise radial velocities". arXiv:1107.5325. Bibcode:2011arXiv1107.5325L. {{cite journal}}: Cite journal requires |journal= (help)
  7. ^ Mugrauer, M.; Ginski, C. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 450 (3): 3127–3136. Bibcode:2015MNRAS.450.3127M. doi:10.1093/mnras/stv771. hdl:1887/49340. Retrieved 19 June 2020.
  8. ^ Howard, Andrew A.; et al. (2010). "The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters". Science. 330 (6004): 653–655. arXiv:1011.0143. Bibcode:2010Sci...330..653H. doi:10.1126/science.1194854. PMID 21030652. S2CID 34792507.
  9. ^ Unger, N.; Ségransan, D.; Queloz, D.; Udry, S.; Lovis, C.; Mordasini, C.; Ahrer, E.; Benz, W.; Bouchy, F.; Delisle, J.-B.; Díaz, R. F.; Dumusque, X.; Lo Curto, G.; Marmier, M.; Mayor, M.; Pepe, F.; Santos, N. C.; Stalport, M.; Alonso, R.; Collier Cameron, A.; Deleuil, M.; Figueira, P.; Gillon, M.; Moutou, C.; Pollacco, D.; Pompei, E. (2021), "The HARPS search for southern extra-solar planets", Astronomy & Astrophysics, 654: A104, arXiv:2108.10198, Bibcode:2021A&A...654A.104U, doi:10.1051/0004-6361/202141351