BD-210397 c
BD-210397 c is a cold gas giant orbiting the K7 V star BD-210397 in the constellation Cetus. It lies about 77 light-years from Earth and was discovered in 2023 using the radial velocity method.
Is BD-210397 c in the Habitable Zone?
The position of BD-210397 c relative to the habitable zone of BD-210397 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on BD-210397 c — one full orbit around BD-210397 — lasts 6,240.0 Earth days, longer than Jupiter's 12-year orbit. It orbits at an average distance of 5.900 AU. Its orbit is highly elliptical (eccentricity 0.43), swinging dramatically closer to and farther from its star.
How Was BD-210397 c Discovered?
BD-210397 c was discovered in 2023 using the radial velocity method, with observations from La Silla 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 BD-210397 c?
BD-210397 c is 77.4 light-years (23.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1949. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,362,240 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. BD-210397 c scores 0.07, ranking #4,826 of 5,565 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: BD-210397
BD-210397
- Spectral type
- K7 V
- Mass
- 0.69 M☉
- Age
- 4.0 billion years (Sun: 4.6)
The BD-210397 Planetary System
BD-210397 c is one of 2 known planets in the BD-210397 system. Its siblings:
- BD-210397 b (Cold Gas Giant)
BD-210397 c — Complete Data
| Mass | 1,525.58 Earth masses (4.800 Jupiter masses) |
|---|---|
| Orbital period | 6,240.00 days |
| Orbital distance | 5.900 AU |
| Eccentricity | 0.430 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 77.4 light-years (23.7 parsecs) |
| Constellation | Cetus |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2023-09-05. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About BD-210397 c
Is BD-210397 c habitable?
BD-210397 c is not known to orbit within the habitable zone of BD-210397, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is BD-210397 c?
BD-210397 c is about 77 light-years from Earth in the constellation Cetus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,362,240 years to get there.
How long is a year on BD-210397 c?
One orbit around BD-210397 takes 6,240.0 Earth days.
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