When One Star Eats Its Brother

Our solar system has but one star (the glorious Sun), but did you know that many have more? For instance, countless binary star systems, consisting of two massive nearby stars orbiting a central gravitational point, exist and thrive, but for the researchers at Caltech, the story becomes really interesting after millions and millions of years, with the death of one companion. We have been using reliable astronomical technology for less than one percent of the lifetime of most stars, so it was tremendously exciting when, for the first time, using the equipment aboard the International Space Station, a conclusive sighting of the above phenomena was declared.

The situation was as follows: consider a binary system with the two stars Alice and Bob. Both stars had fusion reactions in their cores for a long duration of time, but eventually Bob runs out of fuel, loses most of his mass, and becomes a small, but very dense neutron star. Now, the gravitational center of the two-star system is simply Alice; Bob does have enough mass and therefore pull to maintain the common central point. So Bob begins to fall inwards, spiraling until he reaches Alice’s core. Now, Bob begins to steal matter and energy from his former sibling, draining Alice at a fast rate while spurring his own growth, similar to a parasite taking advantage of its host. During the entire process, Alice continues to spew out matter in her star-like fashion and in fact forms a protective envelope around herself and Bob, only worsening the situation for herself. Finally, Bob finishes consuming the core and massive jets of light spew outward, a spectacle in all frequencies of light to enjoy.

This phenomenon has never been documented for a number of reasons. Firstly, the process takes eons to happen, so we have been very lucky to catch one. Secondly, similar explosions in the night sky happen all the time, and it’s difficult to pinpoint exactly why each one occurs. And most importantly, nearly all simulations show Alice dying before Bob finishes consuming her core, so it is extremely difficult to get to the exclusionary phase in the first place. All of the findings have been beautiful to see and fascinating to learn about, but most scientists agree that at the moment, there are no practical applications to the discovery. For now, it’s just another one of nature’s glamorous light surges.