Uncommon exoplanet 31 EP

KMT-2021-BLG-0909L b

RA 265.6202° · Dec -27.6391° · exoplanet

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Score breakdown

· 4 badges

31 pts · Uncommon

Uncommon 33 pts → Rare

Found by microlensing +12
Distant (>1000 ly) +10
Confirmed exoplanet +5
Gas giant +4

Total score 31

2 more points to reach Rare.

Badges

Confirmed exoplanet · +5
Gas giant · +4
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. ≈ 371.4 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 33 million years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 211.3 thousand years in a starship at a tenth of light speed.
Distance. 21.1 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 42.3 thousand years round-trip.

By the numbers

Size. About 13.7× the width of Earth.
Volume. About 2571 Earths could fit inside it.
Mass. Roughly 400× Earth's mass — about 1.3 Jupiters.
Your weight. You'd weigh about 2.1× your Earth weight standing here.
Density. Less dense than water — drop it in a big enough ocean and it would float.

How we found it

Discovery. Found by KMTNet using the microlensing method.

Properties

density gcc: 0.856
discovery facility: KMTNet
discovery method: Microlensing
dist ly: 21134.9088
mass earth: 400.4638
name: KMT-2021-BLG-0909L b
radius earth: 13.7
sys num planets: 1

About KMT-2021-BLG-0909L b

KMT-2021-BLG-0909L b is an uncommon exoplanet. It lies about 21,134.9 light-years from Earth, spans roughly 13.7 Earth radii, weighs about 400.46 Earth masses and belongs to a system of 1 known planets.

About 13.7× the width of Earth.

How to see it

Like any astronomical target, KMT-2021-BLG-0909L 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-0909L b is an uncommon exoplanet

KMT-2021-BLG-0909L b scores 31 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 2 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Gas giant, 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.