HD 75289 is a 6th magnitude star in the constellation of Vela. Like our Sun, it is a yellow dwarf but slightly more massive, hotter and luminous. The spectral type of the star is G0 V. Under exceptionally good circumstances it might be visible to the unaided eye; however, usually binoculars are needed.

In 1999 a planet was discovered orbiting the star, and in 2004 a possible red dwarf companion was detected.

HD 75289 b

HD 75289 b is an extrasolar planet orbiting the star HD 75289. It has a mass half that of Jupiter, and it orbits in a very short orbit completing one revolution around the star in mere three and half days. By studying the starlight scientists have concluded that the planet must have an albedo less than 0.12, rather low for a gaseous giant. Otherwise its reflected light would have been detected.

HD 75289 B

HD 75289 B is a possible red dwarf star orbiting HD 75289. The stars share the same proper motion so they are likely related. Apparent distance between the two stars is about 21.5 arcseconds, at a distance of 94 light years that would be 621 astronomical units. However, the radial distance between the stars is unknown, so they are likely further apart. In any case, one revolution around the primary would take thousands of years to complete.

The study that found the red dwarf also rules out any further stellar companions beyond 140 AUs and massive brown dwarf companions from 400 AU up to 2000 AU.

External links

• SIMBAD star entry, planet entry, component B entry
• The Extrasolar Planets Encyclopaedia entry
• Extrasolar Visions entry
• M. Mugrauer, R. Neuhäuser, T. Mazeh, J. Alves and E. Guenther: M. A low-mass stellar companion of the planet host star HD 75289