HD 154088#Planetary system
{{Short description|Star in the constellation Ophiuchus}}
{{Starbox begin
| name = HD 154088
}}
{{Starbox observe
| epoch = J2000.0
| constell = Ophiuchus
| appmag_v = {{val|6.584|0.010}}
}}
{{Starbox character
| type = subgiant
}}
{{Starbox astrometry
| radial_v = {{val|14.2972|0.0003}}
| parallax = 54.726
| p_error = 0.0236
}}
{{Starbox detail
| luminosity = 0.68{{±|0.06|0.05}}
| temperature = {{val|fmt=commas|5374|43}}
| metal_fe = {{val|+0.28|0.03}}
| rotation = {{val|42.6|4.4}} days
| rotational_velocity = {{val|1.9|0.5}}
}}
{{Starbox catalog
| names = {{odlist|HIP=83541|GJ=652|CD=−28°12769|SAO=184990}}
}}
{{Starbox reference
| Simbad = HD+154088
| NSTED = HD-154088
}}
{{Starbox end}}
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
{{Location mark|float=left
|image=HRDiagram.png|alt=|width=300
|label=|position=right
|mark=Iconol teal circle.svg|mark_width=10|mark_link=HD 154088
|x=446|y=584
|caption=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 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.{{cn|date=April 2025}} 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 {{Earth mass|sym=y|6|link=y}}, 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 = {{Earth mass|sym=y|6.5|link=y}}), and so may be the same detection. The planet's existence was finally confirmed and formally published in 2021.
{{OrbitboxPlanet begin
}}
{{OrbitboxPlanet
| exoplanet = b
| mass_earth = {{val|p=≥|6.6|0.8}}
| period = {{val|18.56|0.01}}
| semimajor = {{val|0.134|0.002}}
| eccentricity = <0.344
}}
{{Orbitbox end}}
References
{{reflist|refs=
{{cite Gaia DR3|6029992663310612096}}
|language=en |volume=355 |pages=L27–L30 |issn=0004-6361}}
}}
{{Sky|17|04|27.84|-|28|34|57.64|58}}
{{Stars of Ophiuchus}}
{{DEFAULTSORT:HD 154088}}