Astronomers using the Atacama Large Millimeter/Submillimeter Array (ALMA)
in norther Chile spied something strange around the dying red giant star
R Sculptoris: a spiral structure thought to be made of gases being expelled
by the star.
By studying the corkscrewed expulsion from R Sculptoris, the astronomers
calculated that the star was shedding more mass during thermal pulses
than had been estimated."This means that much more mass is lost during a time where new
elements cannot yet be incorporated into the wind," Maercker said.
"Hence it will take longer for these elements to be blown into
space – most likely, only during the next pulse."The spiral shape was caused by a companion star pushing through the
layers expelled by T Sculptoris. The formation is allowing the scientists
to study the history of the thermal pulses: Elements blown off at higher
speeds create more widely separated spirals, while phases of slower
mass loss are more tightly packed. The intensity of the spiral reveals
how much mass was lost in each phase."Now that the companion star causes the spiral structure in the
stellar wind from R Sculptoris, we can see it and, in a very detailed
way, measure how it has evolved since the last thermal pulse,"
Maercker said.
Nora Taylor Redd of SPACE.com has more: Link
| Video
of the Star Spiral
