TOI-1246 e: 4-Planet System, 0.212 AU Out
Mini-neptune around TOI-1246
It is 3.51 times Earth's radius, closest in size to Neptune, and 14.5 times Earth's mass, at 1.83 g/cm3, less dense than Earth. A year there lasts 37.93 days, on an orbit 2 times closer to its star than Mercury is to the Sun. Its equilibrium temperature is 464 K, hotter than any desert. The host star TOI-1246 runs at 5213 K with 0.89 times the Sun's mass.
TOI-1246 from the inside out
Orbit
/
Planet
Radius
3.51 Earth radii
Mass
14.5 Earth masses
Equilibrium temperature
464 K (measured)
One year
37.93 days
Orbit radius
0.2120 AU
Host star
TOI-1246 at 5213 K
Distance
553 light-years
Starlight blocked
0.138% at each transit
What you get from the shadow
How deep the star dims fixes the planet's size relative to it.
TOI-1246 has 4 known planets. Systems like this are the ones where architecture can be studied instead of guessed at.
Found by Transiting Exoplanet Survey Satellite (TESS) in 2022. 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.
Size from the shadow, mass from elsewhere. Most transiting planets never get the second half, and without it composition stays a guess.
