About HR 8799 b
HR 8799 b is an epic exoplanet. It lies about 134.5 light-years from Earth, has an equilibrium temperature near 1,200 K, spans roughly 13 Earth radii and weighs about 2,000 Earth masses.
One of at least 4 planets orbiting its star.
Epic exoplanet 51 EP
HR 8799 b
RA 346.8701° · Dec 21.1340° · exoplanet
Score breakdown
· 6 badgesEpic 68 pts → Anomaly
- Directly imaged +16
- Hot Jupiter +10
- Long-period world +10
- Multi-planet system +6
- Confirmed exoplanet +5
- Gas giant +4
Total score 51
17 more points to reach Anomaly.
Badges
- Confirmed exoplanet · +5
- Gas giant · +4
- Hot Jupiter · +10
- Long-period world · +10
- Multi-planet system · +6
- Directly imaged · +16
Trivia
Could we get there?
- Verdict. Hopelessly far for any craft humanity can build today.
Getting there
- Aboard Voyager 1. ≈ 2.4 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 210 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 1345 years in a starship at a tenth of light speed.
- Distance. 135 light-years from Earth.
Look-back time
- Look-back time. The light you'd see left around the year 1891.
Saying hello
- Say hello. A radio message and its reply would take 269 years round-trip.
Standing on it
- A year here. A full year lasts about 465 Earth years.
By the numbers
- Size. About 13× the width of Earth.
- Volume. About 2197 Earths could fit inside it.
- Mass. Roughly 2000× Earth's mass — about 6.3 Jupiters.
- Your weight. You'd weigh about 11.8× your Earth weight standing here.
- Temperature. Around 927°C — hotter than a self-cleaning oven.
How we found it
- Discovery. Found by Gemini Observatory using the imaging method.
Cosmic context
- Crowded system. One of at least 4 planets orbiting its star.
Properties
- density gcc
- 5
- discovery facility
- Gemini Observatory
- discovery method
- Imaging
- dist ly
- 134.5201
- eq temp k
- 1200
- insolation
- 0.0011
- mass earth
- 2000
- name
- HR 8799 b
- orbital period days
- 170000
- radius earth
- 13
- sys num planets
- 4
How to see it
Like any astronomical target, HR 8799 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 HR 8799 b is an epic exoplanet
HR 8799 b scores 51 points on Spacedle's rarity scale, which places it in the epic tier. Another 17 points would lift it into a rarer tier.
That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter, Long-period world, Multi-planet system and Directly imaged — 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.