Circinus X-1

CXC Logo
Chandra X-ray
Observatory Center
Harvard-Smithsonian Center for Astrophysics
60 Garden St. Cambridge, MA 02138 USA

Circinus X-1: A binary-star system 20,000 light years from Earth in the constellation of Circinus.
(Credit: NASA/Penn State/MIT/N.Brandt and N.Schulz)

Caption: This animation shows the strong variability over time of the "P Cygni" spectral lines in Circinus X-1 obtained by the Chandra X-ray Observatory. The distinctive spectral signature from Circinus X-1 is produced by a 4.5-million-mile-per-hour wind from a compact pair of orbiting stars in our Galaxy. The P Cygni profile, never detected before in X rays prior to Chandra’s observation of Circinus X-1, is a textbook tool used by scientists to study stellar winds.

Chandra X-ray Observatory ACIS/HETG Image

CXC operated for NASA by the Smithsonian Astrophysical Observatory