Astronomers Discover a New Kind of Binary Star System With Mysterious Behavior

Firsts are always exciting especially in space like the first planet orbiting three stars at once. Now, astronomers, have discovered the first-ever fully developed shell of a common envelope system with the help of scientific amateurs.

“Toward the end of their lives, normal stars inflate into red giant stars. Since a very large fraction of stars are in binary stars, this affects the evolution at the end of their lives. In close binary systems, the inflating outer part of a star merges as a common envelope around both stars. However, inside this gas envelope the cores of the two stars are practically undisturbed and follow their evolution like independent single stars,” explained astrophysicist Stefan Kimeswenger from the Universitat of Innsbruck Department of Astro and Particle Physics in a press release.

How did a bunch of amateur astronomers come about such an important discovery? The group of German-French researchers slaved over historical celestial images for unknown objects in digitized archives finally identifying a fragment of a nebula on photographic plates from the 1980s.

They then reached out to the professionals at Universitat Innsbruck. The researchers there compiled observations from the past 20 years bringing together data from public archives of various telescopes and from four different space satellites.

This allowed them to rule out the possibility of their first assumption: that the newfound object was a planetary nebula caused by the remnants of dying stars. Then, professionals in the United States finally used measurements taken by telescopes in Chile and spectrographs to draw the final conclusion.

They found that since the object lay slightly above the Milky Way, the nebula was able to develop largely undisturbed by other clouds in the surrounding gas. This allowed them to create a model of the celestial object that is now in the phase of the common envelope of a binary star system.

The results of the study have now been published in the journal Astronomy & Astrophysics. For details of another mysterious nebula, read this story.