Hubble Photographs One of the Smallest Stellar Companions Ever Seen

This NASA Hubble Space Telescope image shows one of the smallest objects ever seen around a normal star. Astronomers believe the object is a brown dwarf because it is 12 times more massive than Jupiter. The brown dwarf candidate, called CHXR 73 B, is the bright spot at lower right. It orbits a red dwarf star, dubbed CHXR 73, which is a third less massive than the Sun. At 2 million years old, the star is very young when compared with our middle-aged 4.6-billion-year-old Sun. CHXR 73 B orbits 19.5 billion miles from its star, or roughly 200 times farther than Earth is from the Sun. The star looks significantly larger than CHXR 73 B because it is much brighter than its companion. CHXR 73 B is 1/100 as bright as its star. The cross-shaped diffraction spikes around the star are artifacts produced within the telescope's optics. The star is 500 light-years away from Earth. Hubble's Advanced Camera for Surveys snapped the image in near-infrared light on Feb. 10 and 15, 2005. The color used in the image does not reflect the object's true color. Credit: NASA, ESA, and K. Luhman (Penn State University)