Astronomy:HD 154088
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ophiuchus[1] |
| Right ascension | 17h 04m 27.843s[2] |
| Declination | −28° 34′ 57.64″[2] |
| Apparent magnitude (V) | 6.584±0.010[3] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | K0IV-V[4] |
| B−V color index | 0.814±0.034[1] |
| Astrometry | |
| Radial velocity (Rv) | 14.2972±0.0003[5] km/s |
| Proper motion (μ) | RA: +83.309[2] mas/yr Dec.: −268.614[2] mas/yr |
| Parallax (π) | 54.726 ± 0.0236[2] mas |
| Distance | 59.60 ± 0.03 ly (18.273 ± 0.008 pc) |
| Absolute magnitude (MV) | 5.33[1] |
| Details | |
| Mass | 0.91±0.02[6] M☉ |
| Radius | 0.95±0.03[7] R☉ |
| Luminosity | 0.68+0.06−0.05[8] L☉ |
| Surface gravity (log g) | 4.37±0.07[6] cgs |
| Temperature | 5,374±43[6] K |
| Metallicity [Fe/H] | +0.28±0.03[6] dex |
| Rotation | 42.6±4.4[9] days |
| Rotational velocity (v sin i) | 1.9±0.5[8] km/s |
| Age | 8±2[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 154088 is a seventh magnitude metal-rich K-type subgiant that lies 59.6 light-years away in the constellation of Ophiuchus. The star is orbited by a hot Super-Earth.
Properties
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 K0IV-V, indicating that it has characteristics intermediate to a subgiant and 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.[citation needed] 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.[10] It also has a magnetic cycle similar to the Sun,[9] though its length is not well constrained.
A survey in 2015 ruled out the existence of any additional stellar companions at projected distances from 8 to 119 astronomical units.[11]
Planetary system
A planet orbiting HD 154088 discovered with the HARPS spectrograph was announced in a September 2011 preprint. With a minimum mass of 6 M⊕, the companion falls into the regime of Super-Earths.[5] HD 154088 has also been observed under the Keck Eta-Earth radial velocity survey. A 2010 paper about this survey listed a "Candidate 1" that has similar properties to HD 154088 b (orbital period = 18.1 days, minimum mass = 6.5 M⊕), and so may be the same detection.[12] The planet's existence was finally confirmed and formally published in 2021.[6]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥6.6±0.8 M⊕ | 0.134±0.002 | 18.56±0.01 | <0.344 | — | — |
References
- ↑ 1.0 1.1 1.2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 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.
- ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars" (in en). Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode: 2000A&A...355L..27H.
- ↑ Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal 132 (1): 161. doi:10.1086/504637. Bibcode: 2006AJ....132..161G.
- ↑ 5.0 5.1 "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets". 2011. arXiv:1109.2497 [astro-ph.EP].
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Unger, N.; Ségransan, D.; Queloz, D.; Udry, S.; Lovis, C.; Mordasini, C.; Ahrer, E.; Benz, W. et al. (2021). "The HARPS search for southern extra-solar planets". Astronomy & Astrophysics 654: A104. doi:10.1051/0004-6361/202141351. Bibcode: 2021A&A...654A.104U.
- ↑ Takeda, Genya (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. doi:10.1086/509763. Bibcode: 2007ApJS..168..297T.
- ↑ 8.0 8.1 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. doi:10.1086/430500. Bibcode: 2005ApJS..159..141V.
- ↑ 9.0 9.1 "The HARPS search for southern extra-solar planets. XXXI. Magnetic activity cycles in solar-type stars: statistics and impact on precise radial velocities". 2011. arXiv:1107.5325 [astro-ph.SR].
- ↑ Fossati, L. (2013). "Detection of a magnetic field in three old and inactive solar-like planet-hosting stars". Astronomy 551: A85. doi:10.1051/0004-6361/201220997. Bibcode: 2013A&A...551A..85F.
- ↑ 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. doi:10.1093/mnras/stv771. Bibcode: 2015MNRAS.450.3127M.
- ↑ Howard, Andrew A. (2010). "The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters". Science 330 (6004): 653–655. doi:10.1126/science.1194854. PMID 21030652. Bibcode: 2010Sci...330..653H.
Coordinates: 
17h 04m 27.84s, −28° 34′ 57.64″
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