HD 129899 (HIP 72670; 15 G. Apodis), is a solitary star located in the southern circumpolar constellation Apus, the bird-of-paradise. It has an apparent magnitude of 6.44, [2] placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively far at a distance of 928 light-years based on Gaia DR3 parallax measurements [1] and it is receding with a heliocentric radial velocity of 2.5 km/s . [6] At its current distance, HD 129899's brightness is heavily diminished by an interstellar extinction of 0.55 magnitudes [14] and it has an absolute bolometric magnitude of −1.28. [8]
HD 129899 has a stellar classification of ApSi, [5] indicating that it is an Ap star with an overabundance of silicon in its spectrum. It has 3.43 times the mass of the Sun [4] and 4.95 times the radius of the Sun. [9] It radiates 190 times the luminosity of the Sun from its photosphere at an effective temperature of 10,617 K , [10] giving it a bluish-white hue when viewed in the night sky. It has a near solar metallicity, having an iron abundance of [Fe/H] = −0.01 or 97.7% of the Sun's. [11] At the age of 229 million years, HD 129899 has completed 95% of its main sequence lifetime. [4] Unlike most chemically peculiar stars, HD 129899 spins rapidly with a rotational velocity of 199 km/s . [10]
The object was observed to be an Alpha2 Canum Venaticorum variable that fluctuates between 6.46 and 6.47 within 1.03 days, [3] which corresponds to the period of the rotation. However, this has not been confirmed. HD 129899 has a relatively weak magnetic field of approximately 402±48 gauss. [15]