TO HUMAN eyes, the night time sky is serene, save for the moon and some wandering planets. Peer into area with a telescope that may scan your complete sky in days, nonetheless, and it seems as a fantastic cosmic fireworks show – a riot of bangs and flashes radiating throughout the electromagnetic spectrum, from radio waves to gamma rays.
Astronomers are desirous to catch these fleeting astrophysical phenomena, referred to as transients, as a result of they’ll reveal a fantastic deal concerning the universe, from what matter does in essentially the most excessive circumstances to how the cosmos developed. And we’re about to see much more of them because of the Vera C. Rubin Observatory in Chile, which is anticipated to detect 10 million transients an evening when it switches on subsequent 12 months.
The difficulty is that, for the untrained observer, it may be troublesome to make sense of transients. For starters, similar-looking outbursts can have totally different origins and vice versa, such {that a} single supply can provide rise to a wide range of astrophysical signatures. That alone could make it tough to maintain observe of what’s what.
Right here, then, is a concise primer that additionally serves as a information to the causes and penalties of those ephemeral illuminations – and the way, in some circumstances, they problem our understanding of the physics that governs the universe.
Stellar flares
A dwelling star’s electromagnetic eruptions
Let’s begin with a straightforward one. A stellar flare is an explosion within the ambiance of a star that ends in an intense flash of radiation throughout the electromagnetic spectrum. When our solar flares, as an example, we see a sudden burst of brightness earlier than it shortly …