Uncommon exoplanet 28 EP

Kepler-257 d

RA 297.3160° · Dec 46.0233° · exoplanet

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Score breakdown

· 5 badges

28 pts · Uncommon

Uncommon 33 pts → Rare

Distant (>1000 ly) +10
Multi-planet system +6
Confirmed exoplanet +5
Neptune-like +4
Found by Kepler +3

Total score 28

5 more points to reach Rare.

Badges

Confirmed exoplanet · +5
Neptune-like · +4
Multi-planet system · +6
Found by Kepler · +3
Distant (>1000 ly) · +10

Trivia

Could we get there?

Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

Aboard Voyager 1. ≈ 44.7 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 4 million years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 25.4 thousand years in a starship at a tenth of light speed.
Distance. 2545 light-years from Earth.

Look-back time

Look-back time. Its light left before the last ice age ended.

Saying hello

Say hello. A radio message and its reply would take 5090 years round-trip.

Standing on it

A year here. A full year lasts just 24.7 Earth days.

By the numbers

Size. About 5× the width of Earth.
Volume. About 121 Earths could fit inside it.
Mass. About 21.7× the mass of Earth.
Your weight. You'd weigh about 0.9× your Earth weight standing here.
Density. Less dense than water — drop it in a big enough ocean and it would float.
Temperature. A scorching 294°C on average.

How we found it

Discovery. Found by Kepler using the transit method.

Cosmic context

Crowded system. One of at least 3 planets orbiting its star.

Properties

density gcc: 0.983
discovery facility: Kepler
discovery method: Transit
dist ly: 2544.8518
eccentricity: 0
eq temp k: 567
insolation: 15.2
mass earth: 21.7
name: Kepler-257 d
orbital period days: 24.6646
radius earth: 4.95
sys num planets: 3

Nearby objects

About Kepler-257 d

Kepler-257 d is an uncommon exoplanet. It lies about 2,544.9 light-years from Earth, has an equilibrium temperature near 567 K, spans roughly 4.95 Earth radii and weighs about 21.7 Earth masses.

One of at least 3 planets orbiting its star.

How to see it

Like any astronomical target, Kepler-257 d 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 Kepler-257 d is an uncommon exoplanet

Kepler-257 d scores 28 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Neptune-like, Multi-planet system, Found by Kepler and Distant (>1000 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.