:INFO
Terrestrial around Kepler-186
It is 1.17 times Earth's radius, closest in size to Earth. A year there lasts 129.94 days, on an orbit 1.1 times Mercury's distance from the Sun. Its equilibrium temperature is 182 K (derived from the star rather than measured), colder than anywhere on Earth. The host star Kepler-186 runs at 3755 K with 0.54 times the Sun's mass.

:JOURNEY
Kepler-186 from the inside out
1 0.034 AU
2 0.045 AU
3 0.078 AU
4 0.110 AU
5 0.432 AU

:CHECKLIST
The habitability checklist, honestly scored
[ ] On the edge of the habitable zone. Borderline.
[ ] A measured mass, not just a radius. No.
[ ] A measured temperature rather than one derived from the star. No.
[ ] Any detection of an atmosphere. Not recorded in the archive.

:STATS
[icon:TARGET] Radius | 1.17 Earth radii
[icon:FIRE] Equilibrium temperature | 182 K (derived)
[icon:CLOCK] One year | 129.94 days
[icon:BOLT] Orbit radius | 0.4320 AU
[icon:STAR] Host star | Kepler-186 at 3755 K
[icon:USERS] Distance | 579 light-years
[icon:TRENDING_DOWN] Starlight blocked | 0.042% at each transit

:PATH
What a crossing measures
Block a known fraction of a known star and you have measured a width.

:NOTE
The archive lists no measured equilibrium temperature for this planet. The 182 K quoted here is derived from the star's output and the orbital distance, assuming a third of the light is reflected. It is an estimate from two numbers, not an observation.

:NOTE
Found by Kepler in 2014. Kepler watched a single field continuously, so it found the planets that come round often. A world with a long year simply never repeated within the mission.

:NOTE.half
The detection is a shadow crossing a disc. Shadows have no weight, which is the whole reason the mass column is empty.

:NOTE.half
Kepler-186 has 5 known planets. Multi-planet systems are where orbital dynamics can be measured rather than assumed.

:THREAD

:LINK
https://exoplanetarchive.ipac.caltech.edu/overview/Kepler-186%20f
NASA Exoplanet Archive: every published measurement of this planet