HIP 5158 b
HIP 5158 b
confirmed planet • updated: 2019-09-04
HIP 5158 b orbits the star HIP 5158, located about 51.6 light-years away. Scientists found it in 2009 using the radial velocity method at La Silla Observatory.
This page summarizes catalog data. Missing values are not guessed or filled in. When multiple studies report slightly different numbers, we show the range to reflect uncertainty, not pick one as 'best' without evidence.
Scientific context
Scientific context: This profile layers interpretation on top of archival measurements. Modeled bands appear where direct detections (like spectra or transits) are not listed.
What we can’t claim: surface conditions, biology, or breathable atmosphere without direct spectra.
This planet has a minimum mass of about 451 Earth masses (or 1.42 times Jupiter’s mass) and orbits its star every 346 days on a noticeably elliptical path. Because radial velocity gives a minimum mass (often written as m sin i), the true mass could be higher if the orbit is tilted relative to our view.
Glossary (plain English)
- AU: the average Earth–Sun distance.
- Semi-major axis: the planet’s average distance from its star.
- Eccentricity: how oval the orbit is (0 = circle).
- Radial velocity: finding a planet by measuring a star’s tiny “wobble.”
- m·sin i: a minimum mass estimate; the true mass can be higher if the orbit is tilted.
- Equilibrium temperature: a rough estimate from starlight alone, not a surface reading.
HIP 5158 b was first reported in 2009 using the Radial Velocity method. The discovery is linked to observations from La Silla Observatory.
Radial-velocity detections come from subtle shifts in the star’s spectrum as it wobbles under the planet’s gravity. The first mass value is often a minimum (m·sin i) unless the orbit’s tilt is known.
The catalog lists an orbital period of about 345.72 days, a semi-major axis near 0.890 AU. The orbit’s eccentricity is 0.52, which describes how stretched the orbit is.
A higher eccentricity can imply stronger past interactions or migration, and it can matter for long‑term stability in multi‑planet systems. Because this is a multi‑planet system, stability is ultimately tested with dynamical (N‑body) fits; catalogs can update as models improve.
The archive reports a mass scale of 1.4 MJ.
For radial‑velocity work this is commonly m·sin i (a minimum mass) because the orbital tilt is unknown. A rough radius estimate is shown for UI completeness, but it should not be treated as a measurement.
Why “m·sin i” shows up on RV planets
HIP 5158 b orbits HIP 5158.
A temperature near 4962 K places it on the sun-like side of the main sequence. The system is about 168.3 light‑years away.
Several key parameters are not present in this single catalog row. Missing fields don’t mean the science is unknown—only that this particular snapshot doesn’t carry the values.
In this case the most noticeable gaps are: radius, catalog equilibrium temperature. As new observations arrive, archives often refresh these entries (and sometimes revise earlier numbers).
Scientists keep revisiting systems like this because each new instrument pass can tighten uncertainties: better timing improves the orbit, better spectra improves the star, and better follow‑up can confirm or refute competing solutions. Even when a planet is well‑established, refined stellar properties can shift the inferred planet size, temperature, and habitability context.