RA 299.5017° · Dec 40.6708° · exoplanet
14 more points to reach Epic.
Kepler-399 d is a rare exoplanet. It lies about 2,415.3 light-years from Earth, shines at apparent magnitude 14.69, has an equilibrium temperature near 486 K and spans roughly 1.89 Earth radii.
It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.
At apparent magnitude 14.69, it takes a larger telescope or a long-exposure image to capture.
Like any astronomical target, Kepler-399 d is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.
Kepler-399 d scores 36 points on Spacedle's rarity scale, which places it in the rare tier. Another 14 points would lift it into a rarer tier.
That score comes from 6 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Super-Earth, Multi-planet system, Found by Kepler and Orbits a Sun-like star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.