Rare exoplanet 35 EP

KMT-2021-BLG-1391L b

RA 270.6836° · Dec -28.0605° · exoplanet

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Score breakdown

· 4 badges

35 pts · Rare

Rare 46 pts → Epic

Found by microlensing +12
Distant (>1000 ly) +10
Super-Earth +8
Confirmed exoplanet +5

Total score 35

11 more points to reach Epic.

Badges

Confirmed exoplanet · +5
Super-Earth · +8
Found by microlensing · +12
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. ≈ 327.8 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 29.1 million years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 186.6 thousand years in a starship at a tenth of light speed.
Distance. 18.7 thousand light-years from Earth.

Look-back time

Look-back time. This light set out before Homo sapiens existed.

Saying hello

Say hello. A radio message and its reply would take 37.3 thousand years round-trip.

By the numbers

Size. About 2× the width of Earth.
Volume. About 7.6 Earths could fit inside it.
Mass. About 4.5× the mass of Earth.
Your weight. You'd weigh about 1.2× your Earth weight standing here.

How we found it

Discovery. Found by KMTNet using the microlensing method.

Properties

density gcc: 3.27
discovery facility: KMTNet
discovery method: Microlensing
dist ly: 18656.1232
mass earth: 4.55
name: KMT-2021-BLG-1391L b
radius earth: 1.97
sys num planets: 1

About KMT-2021-BLG-1391L b

KMT-2021-BLG-1391L b is a rare exoplanet. It lies about 18,656.1 light-years from Earth, spans roughly 1.97 Earth radii, weighs about 4.55 Earth masses and belongs to a system of 1 known planets.

About 2× the width of Earth.

How to see it

Like any astronomical target, KMT-2021-BLG-1391L 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 KMT-2021-BLG-1391L b is a rare exoplanet

KMT-2021-BLG-1391L b scores 35 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Super-Earth, Found by microlensing 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.