Iota Draconis c

Lore & Background

The planetary companion discovered in 2002 was the first planet known to orbit a giant star. In 2021, another long-period planet or brown dwarf was discovered in the same system, designated Iota Draconis c. The true masses of both planets were measured via astrometry. The host star, Iota Draconis, is an evolved K2 III red giant with 1.6 times the mass and nearly 12 times the radius of the Sun, located about 101.2 light-years away in the constellation Draco.

Reader's Guide

The discovery of Iota Draconis c in 2021 expanded the known planetary system around a red giant star, a class of host that was first represented by Iota Draconis b in 2002. The system's importance lies in demonstrating that evolved stars can host multiple long-period companions, and that astrometry can be used to measure true masses of such objects.

The star itself, Edasich, is historically notable as the faintest star with a color reported in pre-telescopic times, classified as orange-red. The system also shows an infrared excess at 70μm suggesting a debris disk. The naming of the planet Hypatia in 2015 through the IAU's NameExoWorlds process reflects public engagement with exoplanet nomenclature.