Spiralling stars

by K.E.M.

May 1999


Using a telescope at the Keck Observatory in Hawaii, astronomers have discovered a new star where spun-off stellar material is being dragged into a spiralling tail.

 WR104: a spiral pinwheel star. This is a movie based on real time-lapse images from April, June and September 1998 (c/o Space Sciences Laboratory, University of California at Berkeley).

WR104: a spiral pinwheel star. This is a movie based on real time-lapse images from April, June and September 1998 (c/o Space Sciences Laboratory, University of California at Berkeley).

Star WR104 is one of about 200 known so-called Wolf-Rayet stars (named after their discoverers). Such stars are in a phase where they are hot, massive and extremely luminous - typically three times the size, 25 times heavier and 100,000 times brighter than our own sun. In this relatively short-lived Wolf-Rayet phase, the pressure of the intensely bright emitted light can expel the star's outer atmosphere.

Not all Wolf-Rayet stars will form a spiralling tail. The reason why WR104 appears as it does is that it has a companion star. As the two stars orbit around each other, WR104 shoots material around its companion and the circling orbits drag this into a spiral.

APOD
WR104 at Astronomy Picture of the Day.
Blowing Bubbles
A Wolf-Rayet Star Blows Bubbles, from Astronomy Picture Of The Day
Exploding
An exploding Wolf-Rayet star, from the Observatorium Hoher