About GJ 15 A b
GJ 15 A b is an uncommon exoplanet. It lies about 11.6 light-years from Earth, has an equilibrium temperature near 550 K, spans roughly 1.55 Earth radii and weighs about 3.03 Earth masses.
One of at least 2 planets orbiting its star.
Uncommon exoplanet 31 EP
GJ 15 A b
RA 4.6127° · Dec 44.0247° · 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. A multi-generation starship could one day attempt the crossing.
Getting there
- Aboard Voyager 1. ≈ 204.2 thousand years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 18.1 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 116 years in a starship at a tenth of light speed.
- Distance. 11.6 light-years from Earth.
Look-back time
- Look-back time. The light you'd see left around the year 2014.
Saying hello
- Say hello. A radio message and its reply would take 23.2 years round-trip.
Standing on it
- A year here. A full year lasts just 11.4 Earth days.
By the numbers
- Size. About 1.6× the width of Earth.
- Mass. About 3× the mass of Earth.
- Your weight. You'd weigh about 1.3× your Earth weight standing here.
- Temperature. A scorching 277°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
- 4.47
- discovery facility
- W. M. Keck Observatory
- discovery method
- Radial Velocity
- dist ly
- 11.6186
- eccentricity
- 0.094
- eq temp k
- 550
- insolation
- 4.2691
- mass earth
- 3.03
- name
- GJ 15 A b
- orbital period days
- 11.4407
- radius earth
- 1.55
- sys num planets
- 2
How to see it
Like any astronomical target, GJ 15 A 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 15 A b is an uncommon exoplanet
GJ 15 A 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.