Rare 'teardrop' star and its invisible partner are doomed to explode in a massive supernova

Astronomers have discovered a rare, teardrop-shaped star swirling through the cosmos some 1,500 light-years from the sun.

Why does the star cry? Because it is in a toxic relationship with a partner that is literally ripping the life from its body. In stellar relationships like these, there is no amicable uncoupling; the romance only ends when both stars explode in a violent, thermonuclear explosion that's visible across the galaxy. You'd cry, too.

But astronomers (cosmic paparazzi that they are) are fired up about this twisted stellar relationship. The star system, named HD265435, is one of only three known binary star systems in the universe — and the closest one to Earth — that is clearly destined to end in a Type Ia supernova, according to a study published July 12 in the journal Nature Astronomy.

These types of stellar explosions occur when a white dwarf (the shriveled husk of an old, collapsed star) shares an orbit with a larger, younger star that still has some fuel left to burn. Small but gravitationally massive, the white dwarf gladly gobbles up this fuel, yanking so much matter away from its companion that the younger star begins to change shape from a sphere into an ellipse, or teardrop. The older star grows larger and larger over millions of years, finally becoming too big for its own good. Nuclear reactions reignite in its core, the dwarf goes boom and both stars become an irradiated smudge of gas and dust in the night sky.