HD 89744

HD 89744 is a star in the northern circumpolar constellation of Ursa Major, positioned about 0.4° due south of the bright star Tania Australis (μ UMa).^[13] This object has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.73.^[2] The distance to this star has been measured using the parallax method, which locates it 126 light years from the Sun. It is drifting closer with a radial velocity of −4.4 km/s.^[2] There are two known exoplanets orbiting this star.

At various times the star HD 89744 has been assigned a stellar classification of F7V,^[4][14] F7IV-V,^[15] and F8IV,^[5][2] suggesting it is an F-type main-sequence star that is evolving onto the subgiant branch. It is ~8.4^[9] billion years old with an inactive chromosphere^[15] and is spinning with a projected rotational velocity of 9.3 km/s.^[10] The star is 2.16^[8] times the size of the Sun with 1.4^[7] times the Sun's radius. It is a high metallicity star, showing a greater abundance of heavier elements than in the Sun. The star is radiating 6.4^[9] times the luminosity of the Sun from its photosphere at an effective temperature of 6,381 K.^[7]

This star was identified as a member of the AB Doradus moving group by J. López-Santiago and collaborators in 2006.^[16] It was later shown that its evolutionary state is incompatible with membership.^[17]

In 2001, a faint co-moving companion was identified at an angular separation of 63.1″ from the primary.^[18] This is equivalent to a linear projected separation of 2,456 AU (0.04 ly).^[11] The companion, designated component B, is an L-class (~L0.5)^[4] brown dwarf^[18] with a mass of ~0.076 M_☉.^[11]