Cosmic records
gravityfinder answers 38 records from measured data: the hottest, coldest, densest and closest worlds we know, the strongest and gentlest gravity, the biggest sun in any sky, the extremes of the stars these planets orbit, and the record holders among black holes and galaxies.
Each record is one honest superlative: a record holder, the number behind it, the top 25, and how we know. For the guided tours, see the worst places to visit and the best.
Size, mass, temperature: the extremes of the planets themselves.
- What is the hottest known exoplanet?★ KELT-9 b · 3648°C (6598°F)
- What is the hottest known lava world?★ Kepler-1547 b · 2913°C (5275°F)
- What is the coldest known exoplanet?★ WISPIT 2 b · -240°C (-399°F)
- What is the smallest known exoplanet?★ Kepler-37 b · 0.31× Earth's radius
- What is the most Earth-like exoplanet?★ Wolf 1069 b · 0.97
- What is the lightest known exoplanet?★ PSR B1257+12 b · 0.02× Earth's mass
- What is the most massive known exoplanet?★ 2MASS J01033563-5515561 AB b · 13.0× Jupiter's mass
- What is the densest known planet?★ Kepler-406 b · 11.97 g/cm³
- What is the biggest known exoplanet?★ TOI-1408 b · 2.23× Jupiter's radius
- Which exoplanet is closest to Earth in size?★ LHS 475 b · 0.99× Earth's radius
- What is the hottest Neptune-sized planet?★ TOI-3071 b · 1882°C (3419°F)
- What is the coldest known rocky planet?★ GJ 3323 c · -125°C (-194°F)
How far out, how fast around, how lopsided the path.
- What is the closest exoplanet to Earth?★ Proxima Cen b · 4.2 light-years
- Which exoplanet has the shortest year?★ KOI-1843.03 · 4.2 hours
- Which exoplanet has the longest year?★ COCONUTS-2 b · 1,100,616 years
- Which exoplanet has the most eccentric orbit?★ HD 20782 b · 0.950
- Which exoplanet orbits farthest from its star?★ UCAC4 328-061594 b · 19,000 AU
- What is the nearest planet in the habitable zone?★ Proxima Cen b · 4.2 ly
- What is the nearest rocky exoplanet?★ Proxima Cen b · 4.2 ly
- Which exoplanet has a year closest to Earth's?★ Kepler-1536 b · 364.8 days
Gravity, weight, and the size of the sun overhead.
Who was first, which year found the most, and how.
The stars these worlds orbit, at their extremes.
- What is the brightest star with a known planet?★ Pollux · magnitude 1.13
- What is the hottest star with a known planet?★ 2MASS J19383260+4603591 · 29,564 K
- What is the coolest star with a known planet?★ TRAPPIST-1 · 2,566 K
- What is the largest star with a known planet?★ HD 18438 · 88.5× the Sun's radius
- What is the smallest star with a known planet?★ DP Leo · 0.011× the Sun's radius
- What is the most luminous star with a known planet?★ mu2 Sco · 6,300× the Sun
The record holders beyond the planetary catalog.
- What is the most massive black hole?★ M87* · 6.5 billion suns
- What is the nearest black hole to Earth?★ A0620-00 · 3,500 ly
- What is the most distant black hole ever detected?★ GW190403_051519 · 27.0 billion ly
- What is the nearest galaxy to the Milky Way?★ Large Magellanic Cloud · 163,000 ly
- What is the brightest galaxy in the sky?★ Large Magellanic Cloud · magnitude 0.90
Each record is one category computed from a measured or derived value, with disputed rows and physically impossible values excluded. Where a measurement is weak, the page says so in its first sentence rather than in a footnote. We do not crown records we cannot vouch for: there is no most massive galaxy here, because no mass is measured for the galaxies in this catalog.