HD 53143
HD 53143 is a binary star in the Carina constellation, located from the Earth. With an apparent visual magnitude of 6.80, this star is a challenge to view with the naked eye even under ideal viewing conditions.
Characteristics
The components of this binary system are separated by 2.48'.Using the technique of gyrochronology, which measures the age of a low-mass star based on its rotation, HD 53143 A is about old. Depending on the source, the stellar classification for this star is G9 V or K1V, placing it near the borderline between G-type and K-type main sequence stars. In either case, it is generating energy through the thermonuclear fusion of hydrogen at its core. This star is smaller than the Sun, with about 85% of the Sun's radius. It is emitting only 70% of the Sun's luminosity. The effective temperature of the star's outer envelope is cooler than the Sun at, giving it a golden-orange hue.
The secondary has a spectral class of M5.0. It is a red dwarf with 13% of the Sun's mass, 16% of the Sun's radius and only 0.15% of the luminosity of the Sun. It is a flare star.
Debris disk
Image:HD 53143.jpg|thumb|left|Debris disk around the star HD 53143 by the Hubble Space Telescope. The star itself has been hidden by the camera coronograph to make the disk visible.Based upon an excess of infrared emission, a circumstellar debris disk has been found around the primary. This disk is inclined at an angle of about 40–50° to the line of sight from the Earth and it has an estimated mass of more than. This is one of the oldest known debris disk systems and hence may be replenished through the collision of larger bodies. The observed inner edge of the disk is at a distance of from the host star, while it stretches out to twice that distance, or. This debris disk may extend outside this range, as the measurements are limited by the sensitivity of the instruments. The dust appears evenly distributed with no indication of clumping. The eccentricity of the ring is also one of the highest known, at 0.21.