Welcome to the Astro Minute, where we’re exploring the universe sixty seconds at a time. I’m Lauren Smyth, and today we’re looking at novae.



Many stars in our galaxy are in binary systems. When a star in a binary system dies and becomes a white dwarf, its strong gravity can pull in material from its companion, and in time can heat the accreted material to a critical temperature, triggering a runaway thermonuclear reaction and explosion. If the white dwarf remains intact, the explosion is called a nova, and is up to a hundred thousand times more luminous than our sun. Recurrent novae are those that explode repeatedly, like T Coronae Borealis.



Novae occur in our galaxy around forty times per year, but appear naked eye only once every year or two. They are sudden and usually unpredictable, so listen for news of their appearance.



I’m Lauren Smyth, and that’s your AstroMinute.