However, Integral's observations revealed that a slow-spinning neutron star, with an unusually strong magnetic field has likely just begun feeding on material from a neighboring red
giant star.
Summary: TEHRAN (FNA)- An international team of astronomers has produced the first detailed images of the surface of a
giant star outside our solar system, revealing a nearly circular, dust-free atmosphere with complex areas of moving material, known as convection cells or granules, according to a recent study.
Jim Fuller (Caltech) and colleagues used these changes to study a few dozen red
giant stars that had been monitored for years by the Kepler spacecraft.
The shape and the size of its orbit are also unusual for a planet like Kepler-432b that is revolving around a
giant star.
At issue, explained lead study author and doctoral student Ben Shappee, is the identity of the white dwarf's companion - is it another white dwarf, or a
giant star, or even a star like our sun?
No
giant star had ever been discovered with copious amounts of dust in its planetary system," Melis says.
Red
giant stars, on occasion, collide with their companion star and that could lead to removal of up to 90 percent of the red
giant stars' mass.
But does that white dwarf draw material from a Sun-like star, an evolved red
giant star, or from a second white dwarf, or is something more exotic going on.
Astronomers believe that this material was ejected by either a supernova or a
giant star in the region.
Normally, a white dwarf packs the equivalent of the sun's mass into a ball roughly the size of a modest planet, while neutron stars -- the crushed relics of supernova explosions of
giant stars -- can have similar masses but diameters of 40 kilometers or less.
This old astrophysical mystery may have been solved by very long baseline radio interferometry of four old
giant stars that turn out to have unexpectedly strong magnetic fields.
Bell of the University of Maryland in College Park and his colleagues used a high-resolution spectrograph to analyze the visible light emanating from the surfaces of a total of 15 red
giant stars in the two clusters.
