On 26th birthday, Hubble spots star 'inflating' giant bubble

Washington, April 22: Celebrating its 26th year in the low-Earth orbit, the Hubble Space Telescope has captured in stunning clarity what looks like a gigantic cosmic soap bubble being blown into space by a super-hot, massive star.

The object, known as the Bubble Nebula, is a cloud of gas and dust illuminated by the brilliant star within it.

"As Hubble makes its 26th revolution around the Sun, we celebrate the event with a spectacular image of a dynamic and exciting interaction of a young star with its environment," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate at its headquarters in Washington, DC.

"The view of the Bubble Nebula reminds us that Hubble gives us a front row seat to the awe inspiring Universe we live in," Grunsfeld added.

Bubble Nebula, also known as NGC 7635, lies 8,000 light-years away in the constellation Cassiopeia.

This object was first discovered by William Herschel in 1787 and this is not the first time it has caught Hubble's eye.

However, owing to its huge size on the sky, previous Hubble images have only shown small sections of the nebula, providing a much less spectacular overall effect.

Now, a mosaic of four images from Hubble's Wide Field Camera 3 (WFC3) allows us to see the whole object in one picture for the first time.

The nebula shell is the result of a powerful flow of gas -- known as a stellar wind -- from the bright star visible just to the left of centre in this image.

The star, SAO 20575, is between 10-20 times the mass of the Sun and the pressure created by its stellar wind forces the surrounding interstellar material outwards into this bubble-like form.

Although the sphere already measures around 10 light-years in diameter, gas on the star gets so hot that it escapes away into space as a "stellar wind" moving at over four million miles per hour.

The NASA/ESA Hubble Space Telescope was launched on April 24, 1990 into the low-Earth orbit aboard the space shuttle Discovery as the first space telescope of its kind.

IANS