Aster › Space program › LTT 9779 b (hot Neptune)
LTT 9779 b (hot Neptune)
Position on the route: 114/130 · level needed 2150 · journey (Mk0 engine) 391.1 h
By the numbers
| Distance | ≈ 262 light-years |
|---|---|
| Radius | ≈ 4.7 Earths |
| Mass | ≈ 29 Earths |
| Year | 19 hours |
The story
LTT 9779 b is an ultra-hot Neptune found by TESS in 2020: so close to its star that a year lasts 19 hours and the day side reaches about 1,700 °C. Normally a Neptune-sized planet this close should have its gas boiled away by starlight; astronomers call this the ‘Neptune desert’ because almost no planets are found there.
This planet is an exception: JWST (2024) showed a thick, metal-rich atmosphere, so it has managed to hold on to its gas. Perhaps it is the remnant core of a once larger giant.
Missions
- TESS (NASA, 2018–): the discovery
- JWST (2024): a metal-rich atmosphere
Colony note
No surface; an orbital station. Ascendant territory.
☠ A hot Neptune so close to its star that its envelope boils away: no surface. An orbital station only.
What probes bring back
- An ultra-hot Neptune in the ‘Neptune desert’: a 19-hour year, radius ≈ 4.7 Earths, mass ≈ 29 Earths; its star is boiling its gas away.
- That it keeps an atmosphere is surprising: JWST (2024) showed a metal-rich one.