By BBC News Online Science Editor Dr David Whitehouse

The Hubble Space Telescope (HST) is back in business and better than ever, as made dramatically clear by stunning new pictures of remote galaxies and a colourful dying star.

The pictures are the first taken by Hubble following a successful space shuttle servicing mission last December. This restored and upgraded the space telescope with new electronics and gyroscopes.

"Thanks to the great work by the astronauts, Hubble is better than new," said Dr Ed Weiler, Nasa Associate Administrator for Space Science.

Steven Beckwith, director of the Space Telescope Science Institute said: "After a two-month hiatus, it is a tremendous boost to all of astronomy to see Hubble back in action. Nasa has restored the observatory to a condition that was better than it was even before the fourth gyroscope failed."

To test the telescope, the astronomers pointed it at two scientifically intriguing and photogenic celestial targets.

Glowing remains

The first of these is a so-called planetary nebula, the glowing remains of a dying, Sun-like star.

This stellar relic, first seen by Sir William Herschel in 1787, is nicknamed the Eskimo Nebula because, when viewed through ground-based telescopes, it resembles a face surrounded by a fur hood.

Planetary nebula expert Patrick Harrington of the University of Maryland said: "Of all the planetary nebulae imaged by the Hubble Space Telescope, this new image is unsurpassed in subtle beauty."

In the Hubble telescope image, the hood is a disk of material surrounded by a ring of comet-shaped objects with their tails streaming away from the central, dying star. In the image nitrogen shines red, hydrogen green, oxygen blue and helium violet.

The bright central region is a bubble of material being blown into space by the central star's intense wind of high-speed material.

Astronomers believe that the planetary nebula began forming about 10,000 years ago, when the dying star began ejecting material into space. It is believed that a ring of dense material around the star's equator was ejected during the star's red giant phase.

The Eskimo Nebula is about 5,000 light-years from Earth in the constellation of Gemini. The picture was taken on 10 January using Hubble's Wide Field and Planetary Camera 2.

Massive cluster

The second object looked at is a massive cluster of galaxies called Abell 2218, which acts like a giant lens in space. The gravitational field of the cluster magnifies the light of more distant galaxies far behind it, providing a deep probe of the very distant Universe.

The cluster was imaged in full colour, providing astronomers with a spectacular and unique new view of the early Universe. "For the first time we can view the internal colour structure of some very distant galaxies. This gives us new insight into details of what young galaxies are like," said Richard Ellis at the California Institute of Technology and the University of Cambridge.

The astronomers are particularly fascinated by an unusual red feature in the field. "This extraordinary object has colours which indicate it is one of two things, either a rare, extremely cool dwarf star in our own galaxy, or one of the most distant objects ever viewed by Hubble lensed into visibility by the mass of the cluster," said Hubble astronomer Dr Andrew Fruchter.