:INFO
Gas giant around TOI-2109
It is 1.35 times Jupiter's radius, closest in size to Jupiter, and 1595.5 times Earth's mass. A year there lasts 16.1 hours, on an orbit 22 times closer to its star than Mercury is to the Sun. Its equilibrium temperature is 3646 K, hotter than the surface of many stars. The host star TOI-2109 runs at 6540 K with 1.45 times the Sun's mass.

:COUNTER
3646 K: hot enough to vaporise rock on the dayside

:STATS
[icon:TARGET] Radius | 15.10 Earth radii
[icon:CHART] Mass | 1595.5 Earth masses
[icon:FIRE] Equilibrium temperature | 3646 K (measured)
[icon:CLOCK] One year | 16.1 hours
[icon:BOLT] Orbit radius | 0.0179 AU
[icon:STAR] Host star | TOI-2109 at 6540 K
[icon:USERS] Distance | 855 light-years
[icon:TRENDING_DOWN] Starlight blocked | 0.663% at each transit

:CHECKLIST
What has been measured here and what has not
[ ] A measured radius. Yes.
[ ] A weight, not just a width. Yes.
[ ] A density, which decides rock or gas. No.
[ ] A semi-major axis. Yes.
[ ] A measured temperature rather than a derived one. Yes.
[ ] An eccentricity, so the orbit shape is known. No.

:PATH
What the transit gives
The depth of the dip is the ratio of the two discs, so the radius follows.

:NOTE
Found by Transiting Exoplanet Survey Satellite (TESS) in 2021. TESS scans most of the sky in 27-day stretches, so it favours bright nearby stars and short orbits over the faint distant ones Kepler specialised in.

:NOTE
Size from the shadow, mass from elsewhere. Most transiting planets never get the second half, and without it composition stays a guess.

:LINK
https://exoplanetarchive.ipac.caltech.edu/overview/TOI-2109%20b
Every parameter ever published for TOI-2109 b, at the NASA Exoplanet Archive