In 2024, a brand new “guest star” will appear within the sky – an area scientist explains how nova events work and where to look

The stars will not be fixed and unchanging, contrary to what many individuals in precedent days thought. Every from time to time a star appears where there was none before, after which it disappears inside days or even weeks.

The first evidence of such a “guest star”, as the traditional Chinese astronomers called it, is a star that suddenly appeared within the sky all around the world on July 4, 1054. It quickly became brighter and was for the subsequent 23 days.

Astronomers in Japan, China and the Middle East observed this event. in addition to the Anasazi in what’s now New Mexico.

In the second half of 2024, a Nova Explosion within the star system T Coronae Borealis or T CrB will again be visible to people on Earth. T CrB will appear 1,500 times brighter than usual, but it’ll not be as spectacular because the event in 1054.

I’m an area explorer with a passion for teaching physics and astronomy. I really like photographing the night sky and astronomical events, including eclipses, meteor showers, and once-in-a-lifetime astronomical events just like the T CrB Nova. At its best, T CrB can be the fiftieth brightest star within the night sky – brighter than only half the celebrities within the Big Dipper. It might take some effort to search out it, but when you have got the time, you'll witness a rare event.

What is a Nova?

In 1572, the famous Danish astronomer Tycho Brahe discovered a brand new star within the constellation Cassiopeia. After recording the event in his Work “De Nova Stella” or “On the New Star”, Astronomers associated the word nova with stellar explosions.

Stars, irrespective of what size, spend 90% of their lives Hydrogen will fuse into helium of their core. However, how a star's life ends will depend on its mass. Very massive stars – those with greater than eight times the mass of our sun – explode in dramatic supernova Explosions like those people observed in 1054 and 1572.

For lower mass stars, including our Sun, once the hydrogen within the core is used up, the star expands into what astronomers call a red giant. The red giant is 100 times larger than it was originally and fewer stable. Eventually, only a white dwarf – an Earth-sized remnant of carbon and oxygen. White dwarfs are 100 thousand times denser than diamonds. Unless they’re a part of a Binary star systemthrough which two stars orbit one another, their brightness slowly decreases over billions of years and so they eventually disappear from view.

T CrB is a binary star system – it consists of a red giant and a white dwarf, orbiting one another every 228 days at about half the space between the Earth and the Sun. The red giant is nearing the tip of its life, has expanded dramatically and is feeding material right into a rotating disk of matter generally known as Accretion diskthat surrounds the white dwarf.

Matter from the accretion disk, which consists mainly of hydrogen, spirals in and slowly accumulates on the white dwarf's surface. Over time, this layer of hydrogen becomes thicker and denser until its temperature exceeds 10 million degrees Celsius.

The latest is a out-of-control thermonuclear response much like the detonation of a hydrogen bomb. Once the accretion disk is hot enough, a nova is created, through which the hydrogen is ignited, blown outwards and emitting shiny light.

When will it occur?

Astronomers learn about 10 recurring novelties – Stars which have experienced a nova explosion greater than once. T CrB is probably the most famous of them. It erupts on average every 80 years.

Because T CrB is 2,630 light-years from Earth, it takes light 2,630 years to travel the space from T CrB to Earth. The nova we are going to see later this yr occurred over 2,000 years ago, but its light is not going to reach us until later this yr.

The accumulation of hydrogen on the white dwarf's surface is like sand in an 80-year hourglass. Each time a nova occurs and the hydrogen ignites, the white dwarf itself is unaffected, but its surface is cleaned of hydrogen. Soon after, hydrogen begins to build up on the white dwarf's surface again: the hourglass turns over and the 80-year countdown to the subsequent nova begins again.

Careful observations through the last two novae in 1866 and 1946 showed that T CrB brightened barely about 10 years before the nova became visible from Earth. Then it dimmed briefly. Although scientists will not be sure what causes these brightness changes, this pattern has repeated itself, with a brightening in 2015 and a Dimming in March 2023.

Based on these observations, scientists assume that the nova can be visible to us sometime in 2024.

How shiny will it’s?

Astronomers use a Magnitude system first developed by Hipparchus of Nicaea greater than 2,100 years ago to categorise the brightness of stars. In this technique, a difference of 5 in magnitude means a change in brightness by an element of 100. The smaller the magnitude, the brighter the star.

In dark skies, the human eye can see stars all the way down to magnitude 6. Normally, the visible light we receive from T CrB comes entirely from its red giant, a magnitude 10 star that’s barely visible with binoculars.

During the nova event, the hydrogen shell of the white dwarf explodes will brighten to a strength of two or 3It will briefly develop into the brightest star in its home constellation Corona Borealis. This maximum brightness will only last a couple of hours and inside a couple of days T CrB will now not be visible to the naked eye.

Where should I look?

Corona Borealis will not be a conspicuous constellation. It is embedded about Bootes and to the west of the Great BearHome of the Big Dipper, within the northern sky.

To find the constellation, look due west and find Arcturus, the brightest star on this region of the sky. Then, at 10 p.m. local time in North America, look about halfway between the horizon and the zenith – the purpose directly above you.

Corona Borealis is about 20 degrees above Arcturus. That's concerning the span of a hand, from the tip of the thumb to the tip of the little finger, at arm's length. At its brightest, T CrB is brighter than all the celebrities in Corona Borealis, but not as shiny as Arcturus.

You may also use an interactive star map, like Stellariumor one in every of the numerous apps available for smartphones to locate the constellation. Familiarizing yourself with the celebrities on this region of the sky before the nova will provide help to discover the brand new star as T CrB brightens.

Although T CrB is just too removed from Earth for this event to rival the supernova of 1054, it remains to be a chance to witness a rare astronomical event with our own eyes. For lots of us, this can be a once in a lifetime event.

For children, nevertheless, this event could spark a passion for astronomy, and in 80 years they could have the option to sit up for observing the event again.