HD 154088

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. 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. It also has a magnetic cycle similar to the Sun, 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.

Planetary system

A planet orbiting HD 154088 discovered with the HARPS spectrograph was announced in a September 2011 preprint. With a minimum mass of , the companion falls into the regime of Super-Earths. 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 = ), and so may be the same detection. The planet's existence was finally confirmed and formally published in 2021.

References

References

1. {{cite Gaia DR3. 6029992663310612096
2. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters.
3. (2021). "The HARPS search for southern extra-solar planets". Astronomy & Astrophysics.
4. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society.
5. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal.
6. (2011). "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets".
7. (2013). "Detection of a magnetic field in three old and inactive solar-like planet-hosting stars". Astronomy.
8. (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.
9. (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.
10. (2011). "The HARPS search for southern extra-solar planets. XXXI. Magnetic activity cycles in solar-type stars: statistics and impact on precise radial velocities".
11. (2010). "The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters". Science.