Scientists Shed Light On Supernova Origins

Type Ia supernovae are thought to result when a white dwarf star in a binary system accumulates enough matter from its larger companion. When the white dwarf reaches the critical Chandrasekhar mass, about 1.4 times the mass of our Sun, high internal density and temperature ignite a thermonuclear explosion. Because the masses of Type Ia supernovae are similar, their brightnesses are similar. Berkeley Lab

From The L.A. Times:

The so-called Type 1a supernovae are key to measuring celestial distances. Astronomers find evidence that they're formed by the collision of two white dwarfs.

German astronomers using a U.S. telescope have provided scientists with at least a partial answer to a vexing question: What is the origin of the so-called Type 1a supernovae, which are widely used as celestial mileage markers?

Type 1a supernovae are of special significance to astronomers because all are believed to have essentially the same intrinsic brightness, and because they can be observed from great distances. Thus, by comparing the brightness of any one of them to what it is expected to be, researchers can estimate its distance from Earth and thereby judge the distance of objects near it.

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