Red Rectangle nebula
author: Nasa/ESA/Novapix
reference: a-nep98-00080
Image Size 300 DPI: 5 * 4 cm
Catalogued as HD 44179, this nebula is more commonly called the `Red Rectangle` because of its unique shape and colour as seen with ground-based telescopes. Hubble's sharp pictures show that the Red Rectangle is not really rectangular, but has an X-shaped structure, that astronomers interpret as arising from outflows of gas and dust from the star in the centre. The star at the centre of the Red Rectangle began its life as a star similar to our Sun. It is now nearing the end of its lifetime, and is in the process of ejecting its outer layers to produce the visible nebula. The shedding of the outer layers began about 14 000 years ago, and in a few thousand years, the star will have become smaller and hotter, releasing a flood of ultraviolet light into the surrounding nebula. When this occurs the gas in the nebula will begin to fluoresce, producing a "planetary nebula". At the present time, however, the star is still so cool that atoms in the nebula do not glow and the surrounding dust particles are only visible as they reflect light from the central star. Astronomers have found that the central star is actually a close pair of stars orbiting each other with a period of about 10 1/2 months. This nebula lies about 2 300 light-years from Earth in the direction of the constellation Monoceros. This image was made from observations taken on 17 March 1999 with Hubble's Wide Field Planetary Camera