Every 80 years, the heavens give us a rare gift: a stellar explosion called a nova that eclipses all other cosmic wonders. This celestial fireworks display occurs when a white dwarf star explodes, increasing its brightness ten thousand times. Even with the naked eye, we can enjoy her glory for millions of kilometers and the next show is about to start very soon. NASA scientists and astronomers are patiently waiting to see it, just as we have been eager to see the solar eclipse and Aurora Borealis for the past few years.
At new moon, a white dwarf star pulls in solar material from a nearby red giant. When the heat and pressure from this build up too much, a thermonuclear explosion results. This makes the white dwarf appear brighter in the sky, but it does not disintegrate, and once the explosion dissipates, the star returns to its original brightness. That massive eruption is a nova.
A nova can still be seen with the naked eye for more than a week after it happens. During that time, it will look like a new star has appeared in the sky. According to NASA, the explosion could happen anytime, day or night, between now and September, although scientists say it could take longer.
This NASA video shows what it looks like.
The last of this star system was in 1946
The cosmic light show is caused by T Coronae Borealis, also known as Blaze Star or T CrB. It is a binary star system composed of a white dwarf and an ancient red giant about 3,000 light-years away from Earth in the Northern Corona of the Milky Way. It is part of the Corona Borealis constellation, which creates a distinctive C-shape in the sky, especially in the summer months.
A white dwarf, the dead remnant of a star, is about the size of Earth but has the same mass as the Sun. Meanwhile, an aging red giant is a dying star that is releasing material into space. The massive gravitational force of the white dwarf attracts the ejected material from the red giant. Once a white dwarf has accumulated enough material, the heat will increase enough to cause a volatile thermonuclear reaction. That explosion is called a nova.
The previous nova from this star system occurred in 1946. It’s a cycle that has been going on since it was first discovered over 800 years ago.
“It’s a once-in-a-lifetime event that will create lots of new astronomers and give young people a cosmic event to observe for themselves, ask their own questions and collect their own data,” said Dr. Rebekah Hounsell, Associate Scientist at NASA’s Goddard Space Flight Center. “It will drive the next generation of scientists.”
Where is the Corona Borealis?
You’re probably not as familiar with the Corona Borealis as you are with more easily recognized constellations like the Big Dipper. Hard to find in the night sky unless it’s clear. Light pollution from big cities can also make it difficult to find.
NASA says the easiest way to find the Corona Borealis is to find Vega and Arcturus, the two brightest stars in the Northern Hemisphere. (Skygazing apps for your phone can help with this.) From there, you can basically draw an imaginary line between the two. The Corona Borealis is almost exactly in the middle. Use the image below to see what we mean.
The nova will occur in the constellation Corona Borealis near the constellation Hercules and directly between Vega and Arcturus.
Alternatively, you can also look for the constellation Hercules and Corona Borealis will be right next to it. Remember, you can’t see the star in question until the nova bursts, so if you look up at the sky before that happens, the spot where the nova will appear won’t be visible.
When will it be new?
Nobody knows for sure. All astronomers and scientists know is that a nova is due to explode at any moment. Most agree that the new moon should occur anytime before September, although it may take longer.
Since a nova can happen at any time, NASA relies on citizen astronomers and space enthusiasts to call it when a nova occurs.
“Using social media and email, (observers will) send instant alerts,” said Dr. Elizabeth Hayes, head of the Astroparticle Physics Laboratory at NASA Goddard. “Once again, we count on this global community interaction with T CrB.”
Early detection can also help NASA gather more data about the event to better understand its mechanism.
“We will observe the nova at its peak and during its decline as the visible energy of the explosion fades,” Hounsell said. “But it’s just as important to get the data during the early rise of the eruption – so the data collected by those passionate citizen scientists now looking for the nova will add dramatically to our findings.”
Will I need a telescope to see the nova?
No. NASA says the nova will be visible to the naked eye on a clear night.
However, it is important to know what to look for. The nova will not look like an explosion like you see in Michael Bay movies. It will just look like another star in the sky that wasn’t there before.
It will also be pretty clear so it should be pretty noticeable. Those with binoculars and binoculars will of course have a better view.
What is the difference between a nova and a supernova?
Most people have heard of the term “supernova”. It is the last dying breath of a star when it gets dark. However, this last dying gasp is also the largest explosion humans have ever seen, as the star violently ejects material into space. Scientists believe that supernovae are responsible for elements heavier than iron in the universe. Curiously, even the iron in your blood can be traced back to supernovae or similar cosmic explosions.
A nova, on the other hand, requires two stars. One star is always a white dwarf, while the other is usually a red giant.
There are other types of nov. Hypernovae are supernovae that reach a certain size and brightness. They are usually about 10 times or more brighter than a standard supernova. Another type, the extremely rare kilonova, occurs when two neutron stars collide and release an incredible gravitational wave along with electromagnetic radiation.