Dust disc around a star. Coloured infrared image showing a disc of dust surrounding star HR 4796A. The infrared light comes from fine particles of dust being heated by the star's ultraviolet and visible light. The star is about 10 million years old, and is a few times more massive than our Sun. The disc is about 250 astronomical units (AU, 1AU= 150 million km) across. Research suggests that the dust near the star has been swept out, possibly by the gravity of newly-formed planets. This image was made at a wavelength of 19.2 micrometres using a 4-metre telescope at the Cerro Tololo Inter- American Observatory (CTIO), Chile.