ZTF J1828+2308 b
ZTF J1828+2308 b is a hot Jupiter orbiting ZTF J1828+2308 in the constellation Hercules. It lies about 658 light-years from Earth and was discovered in 2025 using the transit method.
How Big Is ZTF J1828+2308 b?
ZTF J1828+2308 b has a radius of 11.13 times that of Earth, or 0.99 times the radius of Jupiter. Its mass is 6,357 times that of Earth.
Is ZTF J1828+2308 b in the Habitable Zone?
The position of ZTF J1828+2308 b relative to the habitable zone of ZTF J1828+2308 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on ZTF J1828+2308 b — one full orbit around ZTF J1828+2308 — lasts just 2.7 hours, shorter than Mercury's 88-day year.
How Was ZTF J1828+2308 b Discovered?
ZTF J1828+2308 b was discovered in 2025 using the transit method, with observations from Zwicky Transient Facility.
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is ZTF J1828+2308 b?
ZTF J1828+2308 b is 658.3 light-years (201.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1368. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 11,586,080 years to make the journey.
The Host Star: ZTF J1828+2308
ZTF J1828+2308
- Surface temperature
- 15,900 K (Sun: 5,772 K)
- Mass
- 0.61 M☉
- Radius
- 0.01 R☉
Planetary System
ZTF J1828+2308 b is the only planet known to orbit ZTF J1828+2308 so far.
ZTF J1828+2308 b — Complete Data
| Radius | 11.131 Earth radii (0.993 Jupiter radii) |
|---|---|
| Mass | 6,356.57 Earth masses (20.000 Jupiter masses) |
| Orbital period | 0.11 days |
| Distance from Earth | 658.3 light-years (201.8 parsecs) |
| Constellation | Hercules |
| Discovery method | Transit |
| Discovery facility | Zwicky Transient Facility |
| Discovery year | 2025 |
Data: NASA Exoplanet Archive, last updated 2025-03-25. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About ZTF J1828+2308 b
Is ZTF J1828+2308 b habitable?
ZTF J1828+2308 b is not known to orbit within the habitable zone of ZTF J1828+2308, and as a hot Jupiter it is an unlikely candidate for life as we know it.
How far away is ZTF J1828+2308 b?
ZTF J1828+2308 b is about 658 light-years from Earth in the constellation Hercules. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 11,586,080 years to get there.
How big is ZTF J1828+2308 b compared to Earth?
ZTF J1828+2308 b has 11.13 times the radius of Earth and about 6,357 times its mass.
How long is a year on ZTF J1828+2308 b?
One orbit around ZTF J1828+2308 takes 0.1 Earth days — short enough that 3,261 of its years would fit into one Earth year.
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