Scientists discover solar-like oscillations in massive star

Scientists claim to have discovered a massive star 10 times the mass of Sun but with similar oscillations which could open new possibilities of probing the interiors of celestial bodies and understanding the reasons behind the fluctuations inside the Sun.

Researchers at LESIA, a laboratory of the Paris observatory (France), and AGO, a laboratory of the Lihge University (Belgium) studied the massive star — V1449 Aql (HD180642) — for more than 150 days and observed that it displays solar-like pulsations which have, so far, never been detected in any heavenly body.

The study, conducted by CoRoT space mission, launched on December 27, 2006, has been developed and operated by CNES, a French government space agency, with contribution from Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain.

“The unprecedented high-precision photometric data gathered for this star by the CoRoT mission allows us to report the first detection of solar-like oscillations in a massive star, V1449 Aql,” said Belkacem Kevin, Department of Astrophysics, AGO, in an email interview to PTI.

The Sun oscillates (fluctuations in its diameter) at a period of around five minutes and these motions represent the superposition of literally millions of independent modes, resonating below its surface at extremely precise periods.

“They afford enormous diagnostic potential for the (otherwise invisible) internal structure and dynamics of this conveniently close star,” Kevin said.

The study of oscillations can lead to better understanding of stars’ interiors as well as help physicists learn the reasons behind the cause for the fluctuations taking place in the Sun.

“The mass, age and internal structure of the star itself can be quite well constrained with a seismic study based on information stemmed from those oscillations,” Kevin said.

“It is rather like having discovered the sound of a violin, understanding how the body of the violin resonates and how the bow excites the body of the violin; we can now begin to understand the nature of the arm that forces the bow and how the violin is held!” he explained.

The stellar medium being highly stratified and highly turbulent, the detection of solar-like oscillations in a star well characterised by its seismic properties ought to lead to a better understanding of hydrodynamics in extreme physical conditions, he added.