![ZTF J1828+2308 b: A Year In 2.7 Hours](https://cdn.slatesource.com/4/f/5/4f5d947a-4df5-4dbe-b535-3a7e4182737e.webp)

# ZTF J1828+2308 b: A Year In 2.7 Hours

- [Made in Slatesource](https://slatesource.com/@steph/ztf-j1828-2308-b-a-year-in-2-7-hours)
- By [Steph](https://slatesource.com/@steph)
- Created on Sep 19, 2026

## Gas giant around ZTF J1828+2308

It is 0.99 times Jupiter's radius, closest in size to Jupiter, and 6356.6 times Earth's mass. A year there lasts 2.7 hours. The host star ZTF J1828+2308 runs at 15900 K with 0.61 times the Sun's mass.

**2.7** hours: one full year, start to finish

Radius

11.13 Earth radii

Mass

6356.6 Earth masses

One year

2.7 hours

Host star

ZTF J1828+2308 at 15900 K

Distance

658 light-years

Starlight blocked

6054.236% at each transit

What has been measured here and what has not

0%

A size. Yes.

A mass. Yes.

A density, which decides rock or gas. No.

How far out it orbits. No.

A measured temperature rather than a derived one. No.

The shape of the orbit. No.

What the transit gives

Block a known fraction of a known star and you have measured a width.

Found by Zwicky Transient Facility in 2025.

The size came from a crossing, the mass did not. That pairing is uncommon and it is what lets anyone say whether this is rock or gas.

[NASA Exoplanet Archive: the full record for ZTF J1828+2308 b](https://exoplanetarchive.ipac.caltech.edu/overview/ZTF%20J1828+2308%20b?utm_source=slatesource)