Cosmic Scale
TrES-4b
Puffy hot Jupiter · 1,570 light-years
How big is TrES-4b?
TrES-4b is about 250,300 km across.
See TrES-4b in 3D, at true scale
TrES-4b is a hot Jupiter so puffed up by its star's heat that its density is lower than cork. It orbits in three and a half days and is probably losing its atmosphere into space.
At a glance
| Diameter | 250,300 km |
|---|---|
| Mass | 9.30 × 10²⁶ kg |
| Diameter compared with Earth | 19.6 × Earth |
| Distance | 1,570 light-years |
| Year | 3.6 days |
| Density | 0.2 g/cm³ |
| Found | 2006 |
Good to know
- It is nearly twice Jupiter's width but only half its mass.
- Its gravity is so weak that its upper atmosphere may be streaming away in a comet-like tail.
- Planets like this are hard to explain: heating alone does not seem to account for how inflated they are.
- Next smaller: Proxima Centauri · 214,600 km
- Next larger: Barnard's Star · 260,200 km