Monster star merger on the move

Twin monster stars are merging, in a confirmation of a long-held theory on how supermassive stars are born. A Spanish astronomy team reports the eclipsing binary star system, known as MY Camelopardalis (MY Cam), in the journal, Astronomy & Astrophysics. From Earth, the system's two gigantic stars appear to eclipse one another almost every day, as they circle on a very tight orbit.

By looking at the high-resolution spectra of the two stars with the powerful 2.2-meter telescope at the Calar Alto Observatory in southern Spain, the researchers, led by Javier Lorenzo of Spain's Universidad de Alicante, were able to determine the physical properties of each of the stars, including their surface temperatures and sizes.

The two hot, blue stars, weighing in at 38 and 32 times the mass of our sun, complete orbits of each other in less than 1.2 days. That is so close that the team concludes they are inevitably destined to merge into a single behemoth star, one that will have an astounding 60 times the mass of the sun.

The authors of the recently published study show that MY Cam is already one of the heftiest binary star systems ever seen. In fact, the two stars are likely close enough that their outer atmospheres are already touching and interacting. They are also rotating around each other at whopping speeds of 621,000 miles (one million kilometers) per hour.

Read about astronomical eclipses here.