What is the hottest known exoplanet?
The hottest known exoplanet is KELT-9 b, with an estimated equilibrium temperature of about 3648°C (6598°F), hot enough to vaporize rock and metal. Everything about KELT-9 b →
| # | World | Equilibrium temp | Distance |
|---|---|---|---|
| ★ 1 | KELT-9 b | 3648°C (6598°F) | 667 ly |
| 2 | TOI-2109 b | 3373°C (6103°F) | 855 ly |
| 3 | WASP-189 b | 3080°C (5576°F) | 325 ly |
| 4 | Kepler-1547 b | 2913°C (5275°F) | 2,201 ly |
| 5 | ZTF J1230-2655 b | 2677°C (4850°F) | 609 ly |
| 6 | WASP-33 b | 2509°C (4547°F) | 398 ly |
| 7 | Kepler-770 c | 2467°C (4472°F) | 3,035 ly |
| 8 | HAT-P-7 b | 2460°C (4460°F) | 1,112 ly |
| 9 | HATS-70 b | 2457°C (4454°F) | 4,758 ly |
| 10 | HIP 78530 b | 2427°C (4400°F) | 446 ly |
| 11 | Kepler-1171 b | 2427°C (4400°F) | 1,869 ly |
| 12 | 2MASS J11011926-7732383 b | 2404°C (4359°F) | distance unknown |
| 13 | GQ Lup b | 2377°C (4310°F) | 493 ly |
| 14 | TOI-2260 b | 2336°C (4237°F) | 330 ly |
| 15 | ITG 15 b | 2328°C (4222°F) | 445 ly |
| 16 | WASP-12 b | 2328°C (4222°F) | 1,393 ly |
| 17 | CT Cha b | 2327°C (4220°F) | 622 ly |
| 18 | MASCARA-1 b | 2321°C (4210°F) | 594 ly |
| 19 | HAT-P-70 b | 2289°C (4152°F) | 1,079 ly |
| 20 | KOI-13 b | 2277°C (4130°F) | 1,693 ly |
| 21 | TOI-1518 b | 2273°C (4123°F) | 737 ly |
| 22 | Kepler-1531 b | 2264°C (4107°F) | 2,173 ly |
| 23 | WASP-103 b | 2235°C (4055°F) | 1,225 ly |
| 24 | HIP 77900 b | 2234°C (4053°F) | 492 ly |
| 25 | 2MASS J11550485-7919108 b | 2233°C (4051°F) | 329 ly |
Showing the top 25 of 5,803 that qualify.
The temperature ranked here is the equilibrium temperature: the balance point a world reaches from its star's light alone, computed before any greenhouse effect. Rows flagged as disputed and physically impossible values are excluded, so a bad measurement can never hold the record.
For comparison, the hottest surface in our solar system belongs to Venus, near 465°C. What could unseat this record: transit surveys find new ultra-hot Jupiters every year, and a giant on an even tighter orbit around an even hotter star would take the crown.
What is the hottest known exoplanet?
The hottest known exoplanet is KELT-9 b, with an estimated equilibrium temperature of about 3648°C (6598°F), hot enough to vaporize rock and metal.
How can a planet be hotter than some stars?
It cannot outshine one, but it can match a cool star's surface temperature. KELT-9 b orbits a fiercely hot star from a few stellar radii away, absorbing so much radiation that its dayside runs at 3648°C (6598°F), above the surface temperature of a red dwarf. The heat is borrowed, not generated.
What is an equilibrium temperature?
It is the temperature a world settles at from its star's light alone, before any greenhouse effect from an atmosphere. It is computable for almost every planet in the catalog, which makes it comparable across worlds, and it is a floor rather than a ceiling: a thick atmosphere pushes the real surface hotter, as it does on Venus.
What happens to a planet that hot?
Its atmosphere becomes a chemistry experiment. At these temperatures molecules break apart, metals such as iron and titanium exist as vapour, and the planet trails a comet-like tail of escaping gas. Several of the worlds on this table are visibly evaporating.
Keep exploring: all records · the worst places to visit · all hot Jupiters