Rare exoplanet 41 EP
HD 191939 e
RA 302.0256° · Dec 66.8503° · exoplanet
Score breakdown
· 5 badgesRare 46 pts → Epic
- Richly packed system +14
- Puffy low-density world +12
- Multi-planet system +6
- Confirmed exoplanet +5
- Gas giant +4
Total score 41
5 more points to reach Epic.
Badges
- Confirmed exoplanet · +5
- Gas giant · +4
- Puffy low-density world · +12
- Multi-planet system · +6
- Richly packed system · +14
Trivia
What makes it special
- Cotton-candy planet. So low-density it would float on water.
- Packed system. Crammed into a system of five or more planets.
Could we get there?
- Verdict. Hopelessly far for any craft humanity can build today.
Getting there
- Aboard Voyager 1. ≈ 3.1 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 273 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 1748 years in a starship at a tenth of light speed.
- Distance. 175 light-years from Earth.
Look-back time
- Look-back time. The light you'd see left around the year 1851.
Saying hello
- Say hello. A radio message and its reply would take 350 years round-trip.
Standing on it
- A year here. A full year lasts just 101 Earth days.
By the numbers
- Size. About 13× the width of Earth.
- Volume. About 2197 Earths could fit inside it.
- Mass. Roughly 112× Earth's mass — about 0.4 Jupiters.
- Your weight. You'd weigh about 0.7× your Earth weight standing here.
- Density. Less dense than water — drop it in a big enough ocean and it would float.
- Temperature. A scorching 117°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 6 planets orbiting its star.
Properties
- density gcc
- 0.281
- discovery facility
- W. M. Keck Observatory
- discovery method
- Radial Velocity
- dist ly
- 174.8486
- eccentricity
- 0.031
- eq temp k
- 390
- insolation
- 3.9
- mass earth
- 112.2
- name
- HD 191939 e
- orbital period days
- 101.12
- radius earth
- 13
- sys num planets
- 6