About GJ 251 b
GJ 251 b is an uncommon exoplanet. It lies about 18.2 light-years from Earth, has an equilibrium temperature near 336 K, spans roughly 1.79 Earth radii and weighs about 3.85 Earth masses.
One of at least 2 planets orbiting its star.
Uncommon exoplanet 31 EP
GJ 251 b
RA 103.7002° · Dec 33.2665° · exoplanet
Score breakdown
· 4 badgesUncommon 33 pts → Rare
- Nearby (<25 ly) +12
- Super-Earth +8
- Multi-planet system +6
- Confirmed exoplanet +5
Total score 31
2 more points to reach Rare.
Badges
- Confirmed exoplanet · +5
- Super-Earth · +8
- Multi-planet system · +6
- Nearby (<25 ly) · +12
Trivia
Could we get there?
- Verdict. Hopelessly far for any craft humanity can build today.
Getting there
- Aboard Voyager 1. ≈ 319.8 thousand years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 28.4 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 182 years in a starship at a tenth of light speed.
- Distance. 18.2 light-years from Earth.
Look-back time
- Look-back time. The light you'd see left around the year 2008.
Saying hello
- Say hello. A radio message and its reply would take 36.4 years round-trip.
Standing on it
- A year here. A full year lasts just 14.2 Earth days.
By the numbers
- Size. About 1.8× the width of Earth.
- Volume. About 5.7 Earths could fit inside it.
- Mass. About 3.9× the mass of Earth.
- Your weight. You'd weigh about 1.2× your Earth weight standing here.
- Temperature. A scorching 63°C on average.
How we found it
- Discovery. Found by W. M. Keck Observatory using the radial velocity method.
Cosmic context
- Crowded system. One of at least 2 planets orbiting its star.
Properties
- density gcc
- 3.69
- discovery facility
- W. M. Keck Observatory
- discovery method
- Radial Velocity
- dist ly
- 18.2014
- eccentricity
- 0
- eq temp k
- 336
- insolation
- 2.37
- mass earth
- 3.85
- name
- GJ 251 b
- orbital period days
- 14.237
- radius earth
- 1.79
- sys num planets
- 2
How to see it
Like any astronomical target, GJ 251 b is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.
Why GJ 251 b is an uncommon exoplanet
GJ 251 b scores 31 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 2 points would lift it into a rarer tier.
That score comes from 4 science badges — Confirmed exoplanet, Super-Earth, Multi-planet system and Nearby (<25 ly) — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.