HD 1502

Lore & Background

The star HD 1502 has evolved past the main sequence and is now a subgiant with a spectral type of K0. It has a mass of 1.46 solar masses and a radius of 4.67 solar radii, making it larger and brighter than the Sun despite its cooler effective temperature of 4947 K. The star is slightly richer than the Sun in elements heavier than hydrogen and helium, and at about 3.0 billion years old, it is roughly two-thirds the age of the Sun. Due to its higher mass, it is further evolved than the Sun, which will spend 10 billion years as a main-sequence star.

In 2011, the exoplanet HD 1502 b was discovered using the radial-velocity method. It orbits the star at a distance of 1.262 AU with a period of just over one year in a near-circular orbit. The planet is a super-Jupiter with a minimum mass of 2.75 Jupiter masses and a predicted radius of 1.183 Jupiter radii.

On 17 December 2019, the IAU announced the proper names Citadelle and Indépendance for the star and its planet, respectively. The names were submitted and selected within Haiti as part of the IAU100 NameExoWorlds Project, which granted naming rights to every state and territory. Citadelle refers to the Citadelle Laferrière, a fortress in Milot, northern Haiti, built in 1820 and declared a World Heritage Site in 1982. Indépendance honors the Haitian Declaration of Independence, celebrating the country's independence on 1 January 1804.

Reader's Guide

The HD 1502 system holds significance as one of the exoplanetary systems named through the IAU100 NameExoWorlds Project, which celebrated the hundredth anniversary of the International Astronomical Union by allowing each state and territory to name a star and its planet. The Republic of Haiti selected names deeply rooted in national heritage: Citadelle, after the Citadelle Laferrière fortress, a symbol of Haitian history and a UNESCO World Heritage Site, and Indépendance, after the Haitian Declaration of Independence of 1804. These names connect astronomical discovery to cultural identity and historical milestones. The star itself, a K-type subgiant cooler but larger and brighter than the Sun, and its super-Jupiter planet discovered in 2011 via radial velocity, contribute to the understanding of planetary systems around evolved stars. The system's near-circular orbit and orbital period similar to Earth's year offer a point of comparison with the Solar System. The naming process and the system's characteristics together highlight the intersection of astronomy, international collaboration, and cultural representation.