Two pair of compact white dwarf stars were located around 150 light-years from Earth. They have been identified by a group of astronomers. The two stars are orbiting each other. They are believed to be on course to eventually merge together. The collision is expected to take place in roughly 23 billion years. A Type 1a supernova is likely to result from this merger. This is the first time such a system which is destined to follow this path, has been clearly observed near our region of the galaxy.

First direct evidence linked to future Type 1a supernova

According to a study published in Nature, the system has a combined mass equal to about 1.56 times that of the sun. Such a high mass has confirmed that an eventual explosion is unavoidable. The heavier of the two stars is expected to draw matter from its lighter companion as their orbit gradually tightens. The investigation has been carried out by a team from the University of Warwick using data from large optical telescopes.

Closer orbit to drive merger over time

James Munday, PhD researcher and lead author of the study, shared in a press statement released to Space.com that the team acted quickly to verify the compactness of the system. Measurements revealed the stars currently orbit each other in just over 14 hours. Over time, the orbit is predicted to reduce to less than a minute. At that point, the final stages before the explosion will be reached.

Wider impact on cosmic measurements

Dr Ingrid Pelisoli. Assistant Professor at the University of Warwick and co-author, stated to Space.com that the proximity of this system suggests similar pairs might not be uncommon. Type 1a supernovas are considered useful to astronomers. Their consistent brightness allows measurements of vast distances in space.