The US space agency NASA and ESA’s iconic Hubble Space Telescope (HST) has beamed back last moments of a star which is about to die. The new image released by NASA shows ‘last hurrah’ as the star is about to end its life by casting off its outer layers of gas, which formed a cocoon around the star’s remaining core. The dying star is a white dwarf and is emitting ultraviolet light. NASA scientists revealed that our sun will similarly in another 5 billion years.
Our Milky Way Galaxy is littered with these stellar relics, called planetary nebulae. The objects have nothing to do with planets. Eighteenth- and nineteenth-century astronomers called them the name because through small telescopes they resembled the disks of the distant planets Uranus and Neptune. The planetary nebula in this image is called NGC 2440. The white dwarf at the center of NGC 2440 is one of the hottest known, with a surface temperature of more than 360,000 degrees Fahrenheit (200,000 degrees Celsius).
The nebula’s chaotic structure suggests that the star shed its mass episodically. During each outburst, the star expelled material in a different direction. This can be seen in the two bowtie-shaped lobes. The nebula also is rich in clouds of dust, some of which form long, dark streaks pointing away from the star. NGC 2440 lies about 4,000 light-years from Earth in the direction of the constellation Puppis.
The material expelled by the star glows with different colors depending on its composition, its density and how close it is to the hot central star. Blue samples helium; blue-green oxygen, and red nitrogen and hydrogen.
At present HST is the largest telescope present in space and it will be replaced by the James Webb Telescope in 2018 which has thrice larger lens (8 meters in diameter) than the HST. HST has helped scientists in peeking into the deepest corners of the universe since 1990.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.