Rho Fornacis

Rho Fornacis (ρ For) is a star of apparent magnitude +5.54 in the constellation of Fornax, the furnace. It is found, according to the new reduction of the parallax data from Hipparcos, to 269 light years of the Solar System.

Rho Fornacis is a yellow-orange giant of spectral type G6III with an effective temperature of 4884 K. It is similar, though somewhat hotter, than β Fornacis and π Fornacis, stars also in Fornax. The diameter of Rho Fornacis is 9.9 times larger than the solar diameter but its mass is barely 1% greater than that of the Sun. Its age is estimated at 5180 ± 3170 million years.

Rho Fornacis is a thick disk star, unlike most stars in our environment. Arcturus (α Boötis) and ε Fornacis, the latter in this same constellation, are examples of thick disk stars. The eccentricity of its orbit around the Galactic Center (e = 0.56) is considerably greater than that of the Sun (e = 0.16), star of the thin disk. Consequently, it shows a low metallicity—relative abundance of elements heavier than helium—, less than half that of the solar ([Fe/H] = -0 ,35). Elements such as aluminum, calcium and sodium are equally deficient. As in other similar stars, the oxygen/iron ratio is higher than in the Sun ([O/H] = 0.33).