G Doradus

G Doradus (HD 37297; HR 1917; 28 G. Doradus) is a spectroscopic binary located in the southern constellation Dorado, the dolphinfish. It has an apparent magnitude of 5.34, making it faintly visible to the naked eye under ideal conditions. The system is located relatively close at a distance of 234 light-years based on Gaia DR3 parallax measurements but it is receding with a heliocentric radial velocity of approximately $$. At its current distance, G Doradus' brightness is diminished by a quarter of a magnitude due to interstellar extinction and it has an absolute magnitude of +1.08. The bayer designation "G Doradus" was not assigned by Benjamin Gould or Lacaille. It merely arose due to the designation assigned by Gould; 28 G. Doradus.

The visible component has a stellar classification of G8/K0 III, indicating that it is an evolved star with the characteristics of a G8 and K0 giant star. It has 3.47 times the mass of the Sun but at the age of 556 million years, it has expanded to 10.5 times the radius of the Sun. It radiates 48.4 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of $$, giving it an orangish-yellow hue when viewed in the night sky. G Doradus is slightly metal deficient with an iron abundance of [Fe/H] = −0.20 and it spins too slowly for its projected rotational velocity to be measured accurately.

G Doradus is a single-lined spectroscopic binary; the components – which have a separation of 0.32 AU – take 181 days to circle each other in an elliptical orbit, but the orbit is not well constrained. Although only the primary can be observed in the spectrum, the masses of both components can be determined. Krachieva et al. (1980) derives a mass of for the companion, which might be an A-type star.