About HD 17156 b
HD 17156 b is a common exoplanet. It lies about 254.7 light-years from Earth, has an equilibrium temperature near 888 K, spans roughly 12.26 Earth radii and weighs about 1,036.12 Earth masses.
About 12.3× the width of Earth.
Common exoplanet 18 EP
HD 17156 b
RA 42.4366° · Dec 71.7531° · exoplanet
Score breakdown
· 3 badgesCommon 24 pts → Uncommon
- Eccentric orbit +9
- Confirmed exoplanet +5
- Gas giant +4
Total score 18
6 more points to reach Uncommon.
Badges
- Confirmed exoplanet · +5
- Gas giant · +4
- Eccentric orbit · +9
Trivia
Could we get there?
- Verdict. Hopelessly far for any craft humanity can build today.
Getting there
- Aboard Voyager 1. ≈ 4.5 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 397.7 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 2547 years in a starship at a tenth of light speed.
- Distance. 255 light-years from Earth.
Look-back time
- Look-back time. The light you'd see left around the year 1771.
Saying hello
- Say hello. A radio message and its reply would take 509 years round-trip.
Standing on it
- A year here. A full year lasts just 21.2 Earth days.
By the numbers
- Size. About 12.3× the width of Earth.
- Volume. About 1844 Earths could fit inside it.
- Mass. Roughly 1036× Earth's mass — about 3.3 Jupiters.
- Your weight. You'd weigh about 6.9× your Earth weight standing here.
- Temperature. Around 615°C — hotter than a self-cleaning oven.
How we found it
- Discovery. Found by Subaru Telescope using the radial velocity method.
Properties
- density gcc
- 3.08
- discovery facility
- Subaru Telescope
- discovery method
- Radial Velocity
- dist ly
- 254.6832
- eccentricity
- 0.6772
- eq temp k
- 888
- insolation
- 68.8
- mass earth
- 1036.1206
- name
- HD 17156 b
- orbital period days
- 21.2164
- radius earth
- 12.2626
- sys num planets
- 1
How to see it
Like any astronomical target, HD 17156 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 HD 17156 b is a common exoplanet
HD 17156 b scores 18 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.
That score comes from 3 science badges — Confirmed exoplanet, Gas giant and Eccentric orbit — 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.