Red Novae – New Type of Supernovas

Astronomers have discovered a new class of stellar explosions that are larger than a regular nova but not quite as large as a supernova. The researchers speculate the event is the result from the merger of two ordinary stars 49 million years ago.

It is believed that the red luminous novae occurs when two stars merge and undergo what is called "common envelope evolution". The event known as M85OT2006-1 took place in the Messier 85 galaxy some 60 light years from Earth. In 1960, a Type I supernova named 1960R was discovered in Messier 85.

The team of researchers from Caltech who discovered the red novae in Messier 85 had been speculating on possible new classes of cosmic explosions for some time now. They utilized several telescopes including the Palomar 60-inch telescope, the Hale 200-inch telescope and the Keck telescopes atop Mauna Kea, Hawaii. The scientists explained that the explosion was surprising because it was far too faint for a supernova, in which a star literally explodes, but clearly too bright to be a nova or a thermonuclear explosion from the surface of a white dwarf star.  

The finding, which was published in the recent issue of Nature magazine might very well open a new field of research for astronomers and progress our understanding of the creation and evolution of stars. The discovery was made in the framework of a program aimed at locating supernovas. Although several supernovas were already found the scientists are surely pleased about the unexpected discovery of the red luminous novae and will now reexamine previous mysterious explosions to try and locate more red novae. 

TFOT recently reported the discovery of the brightest supernova ever in the NGC 1260 galaxy, some 240 million light years away from Earth. The supernova, known as SN 2006gy was photographed by NASA’s Chandra X-ray Observatory. SN 2006gy was the result of the explosion of a star believed to be about 150 times more massive than our own sun, making it very close to the theoretical limit of mass for stars in our universe. 

More information on the discovery of the red novae can be found on the Caltech website
Image: Ground-Based Image of Supernova 1994D in Galaxy NGC 4526 (Credit: NASA).