The rings are light echoes from Circinus X-1's X-ray burst.
That phenomenon, Heinz and his colleagues recognized, could give astronomers an opportunity to use the geometry of the rings and a time delay between deflected and undeflected X-rays to calculate the distance to Circinus X-1, a measurement previously unobtainable because the supernova is hidden in the dust that permeates the plane of our galaxy.
But just as bats use sonar to triangulate their location, we can use the X-rays from Circinus
X-1 to figure out exactly where it is.
Using the MIDI instrument at the Very Large Telescope Interferometer of the European Southern Observatory (ESO) in the Atacama Desert of Chile, the research team obtained an unprecedented clear view of the warm dust in the nucleus of the Circinus
, in contrast, seems to flash only once per rotation.
Niel Brandt, Distinguished Professor of Astronomy and Astrophysics, said that he was perplexed by the unusually strong evolution of the orbit of Circinus
X-1 since my graduate-school days, asserting that the discovery now of this system's youth provides a satisfying explanation for why its orbit evolves so strongly - as the system likely still is settling down after its violent birth.
Sebastian Heinz and his team at the University of Wisconsin-Madison (UW) discovered Circinus
X-1 is less than 4,600 years old, making it the youngest X-ray binary system ever seen.
The shape of the Circinus
constellation resembles a long, acute-angled triangle with Alpha Circini pointing SW Beta and Gamma Circini completes the shape of the image, approximately 7 degrees NW.
Also culminating at midnight around the middle of the month is the small southern constellation Circinus
the Compasses, located between the Pointers (alpha and beta Centauri) and the Southern Triangle (Triangulum Australe).
Deep-sky objects Designation Type and constellation NGC 5823 open cluster in Circinus
NGC 6025 open cluster in Tr.
Deep Sky Worth Viewing (binoculars or telescope) Object Type Con Eta Carina Nebula BrtN Car Sombrero Galaxy Glxy Vir Herschel's Jewel Box OpCl Cru Omega Centauri GlCl Cen Trifid Nebula BrtN Sgr Lagoon Nebula BrtN Sgr Omega Nebula BrtN Sgr M41 OpCl Cma M83 Glxy Hya Orion Nebula BrtN Ori Full details on pages 82 to 84 Constellations Day Constellation 01 Circinus
09 Libra, Lupus 20 Corona Borealis 21 Apus, Norma 22 Triang.
Constellations Day Constellation 01 Circinus
20 Corona Borealis 09 Libra, Lupus 21 Apus, Norma 22 Triang.