HD 155193 b
HD 155193 b is a cold gas giant orbiting the F8 IV star HD 155193 in the constellation Ophiuchus. It lies about 189 light-years from Earth and was discovered in 2021 using the radial velocity method.
Is HD 155193 b in the Habitable Zone?
The position of HD 155193 b relative to the habitable zone of HD 155193 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 155193 b — one full orbit around HD 155193 — lasts 352.7 Earth days, between the years of Mercury (88 days) and Earth (365 days). It orbits at an average distance of 1.040 AU — comparable to the inner Solar System. Its orbit is mildly elliptical (eccentricity 0.21).
How Was HD 155193 b Discovered?
HD 155193 b was discovered in 2021 using the radial velocity method, with observations from Haute-Provence Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is HD 155193 b?
HD 155193 b is 188.5 light-years (57.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1838. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 3,317,600 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. HD 155193 b scores 0.25, ranking #3,095 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 155193
HD 155193
- Spectral type
- F8 IV
- Surface temperature
- 6,239 K (Sun: 5,772 K)
- Mass
- 1.22 M☉
Planetary System
HD 155193 b is the only planet known to orbit HD 155193 so far.
HD 155193 b — Complete Data
| Mass (best estimate) | 238.37 Earth masses |
|---|---|
| Orbital period | 352.65 days |
| Orbital distance | 1.040 AU |
| Eccentricity | 0.210 |
| Earth Similarity Index | 0.25 |
| Distance from Earth | 188.5 light-years (57.8 parsecs) |
| Constellation | Ophiuchus |
| Discovery method | Radial Velocity |
| Discovery facility | Haute-Provence Observatory |
| Discovery year | 2021 |
Data: NASA Exoplanet Archive, last updated 2021-05-28. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 155193 b
Is HD 155193 b habitable?
HD 155193 b is not known to orbit within the habitable zone of HD 155193, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HD 155193 b?
HD 155193 b is about 189 light-years from Earth in the constellation Ophiuchus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 3,317,600 years to get there.
How long is a year on HD 155193 b?
One orbit around HD 155193 takes 352.7 Earth days.
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