Look Up! It's A Star In The Midst Of A Violent, Bright Death
Something violent is happening in the night sky, right now. And scientists studying the phenomenon said yesterday that with a pair good binoculars or a telescope you can see a star in its final throes causing a spectacular explosion called a supernova.
Even though the star is 21 million light years away from Earth, the explosion is the closest and brightest astronomers have found in decades. Today will be its brightest night.
The discovery, announced on Wednesday, was made in what was believed to be the first hours of the rare cosmic explosion using a special telescope at the Palomar Observatory near San Diego and powerful supercomputers at a government laboratory in Berkeley.
The detection so early of a supernova so near has created a worldwide stir among astronomers, who are clamoring to observe it with every telescope at their disposal, including the giant Hubble Space Telescope.
The star is located in the Pinwheel Galaxy, and you can spot it, weather permitting, above the Big Dipper. USA Today says the best time to catch it is just after sunset, before the moon brightens the sky.
The paper also explains a bit of the science behind what's going on:
The supernova belongs to the widely observed "Type 1a" group, born from runaway thermonuclear combustion in an ancient "white dwarf" star, the burned-out stub of a normal star that attains a weight 1.38 times heavier than the sun, then blasts itself apart. Type 1a blasts are 10 to 50 times brighter than other supernovas, and the light from the single exploding star is brighter than the light from an entire galaxy.
If such a blast had occurred in our own Milky Way galaxy, the light would probably be visible during the daytime. "In some senses, this is the largest, nearest thermonuclear explosion we can see," [astronomer Peter Nugent of the Energy Department's Lawrence Berkeley (Calif.) National Laboratory] says.
Reuters put together a video with an animation of what's going on:
The BBC spoke to Mark Sullivan, the leader of the team that made the discovery. He points out the last time they saw an explosion like this was in 1972 and before that in 1937 and 1898.
"Whilst it looks more or less like just another bright star, unlike its companions this supernova will soon fade away, and after a few days it will only be visible with larger telescopes," Sullivan told the BBC.
Update at 10:23 a.m. ET. How To Watch:
The Lawrence Berkeley National Laboratory has put together this video on how to spot the supernova using binoculars:
Update at 4:11 p.m. ET. What This Means For Science:
This afternoon, All Things Considered'sMelissa Block spoke to Peter Nugent, the Lawrence Berkeley National Laboratory scientist who discovered the star.
We'll post their conversation here later. But here are a few highlights from it:
-- To put the distance in context, Nugent said they find one to two supernovas a night. Most of them are about one to four billion light years away and some of them are are as far as eight billion light years away. 21 million light years is practically next door by those standards.
-- Nugent says the best time to view the supernova is actually next week. Peak brightness is today, but next week the full moon will be gone and it will be much brighter.
-- Nugent says there are two things everyone should know about supernovas: Beyond helium, supernovas produce almost all the elements in the universe. The second thing is that this type of supernova — Type 1a — is used by scientists to measure how far things in the universe are. The light that supernovas emit is pretty much the same for all of them, so they are a good "standard candle" or constant. This kind of measuring also helps scientists understand how fast galaxies are moving away from each other.
-- Nugent added that there are a couple of things this supernova in particular can help with. First, because they found it in its early stages, it might be able to tell them why and how they explode. Specifically it might shed light on the companion stars that help these stars explode. (The Reuters video above, by the way, does a great job at explaining that aspect of it.) The second thing scientists can learn from this supernova is that it might help them better calibrate their cosmic measurements.
Copyright 2020 NPR. To see more, visit https://www.npr.org.