Solved: 30-year-old mystery of 'planetary nebulae'
Astronomers have resolved a 30-year-old argument, ruling out a one-size-fits-all mechanism for shaping some of the most beautiful objects in space -- the "planetary nebulae".world Updated: Sep 14, 2009 10:30 IST
Astronomers have resolved a 30-year-old argument, ruling out a one-size-fits-all mechanism for shaping some of the most beautiful objects in space -- the "planetary nebulae".
Planetary nebulae have nothing to do with planets, but are enlarged glowing objects that is stars late in their lives which have shed much of their gas into space. Some appear as round blobs and can look like an eye, an ant or an hourglass.
The question is, what forms these shapes? There have been two ideas. One is that a planetary nebula arises from a single star in the late stage of its life. The second idea is two stars are involved with the aged one providing the gas.
Now, an international team, led by Brent Miszalski of the Anglo-Australian Observatory, has clearly ruled it out as a general mechanism for shaping majority of planetary nebulae, the 'Astronomy & Astrophysics' journal reported.
In their research, the team drew on a number of catalogues of planetary nebulae, particularly those derived from the Macquarie/AAO/Strasbourg H-alpha surveys, to amass a collection of hundreds of possible central stars in nebulae.
Using the OGLE-III photometric survey, they then looked for periodic variability in the light of the central star, which could be a sign that the central star was, in fact, a binary—two stars orbiting each other.