HIP 65426 b
HIP 65426 b
confirmed planet • updated: 2017-07-11
HIP 65426 b was spotted directly by a telescope — one of the few exoplanets we’ve actually seen as a dot of light. It orbits a young, bright star about 109 light-years away.
This page summarizes a catalog entry. If a measurement is missing, it is not shown or guessed. Some values can differ slightly between studies; when that happens, we describe the range rather than picking a favorite 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 is very large — about 9 times the mass of Jupiter and 1.5 times its size. It orbits far from its star, at about 92 times Earth’s distance from the Sun. Its surface temperature is estimated at 1500 Kelvin (about 1227°C or 2240°F), likely due to its youth and internal heat. Because it was imaged directly, we have a better idea of its actual mass and size than many other exoplanets.
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 65426 b was first reported in 2017 using the Imaging method. The discovery is linked to observations from Paranal Observatory.
Direct imaging tries to separate faint planetary light from the glare of the host star. It works best for young, warm planets far from their stars.
The catalog lists a semi-major axis near 92.000 AU.
Eccentricity is not provided here; many catalogs omit it when the solution is underconstrained.
The archive reports a mass scale of 9.0 MJ.
A catalog radius is also listed, which (together with mass) helps constrain density and interior structure.
Why “m·sin i” shows up on RV planets
HIP 65426 b orbits HIP 65426. The star is classified as A2 V, which is a shorthand for temperature and color.
A temperature near 8840 K places it on the hotter side of the main sequence. The system is about 355.1 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: orbital period, eccentricity. 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.