As of: April 5, 2024, 7:13 p.m
By: Tanja Banner
Comments
Press
Split
Experts are certain that a “new star” will soon appear in the sky. A nova only happens every 80 years.
Munich – For everyone who regularly and carefully studies the night sky, a remarkable change could emerge in the next few months: a “new star” will appear in the constellation of the Northern Crown (Corona Borealis). But this is not a newly formed star, but rather a celestial body that was previously too faint to be seen with the naked eye.
NASA: Nova from T CrB is “a once-in-a-lifetime observation opportunity”
The star T Coronae Borealis (T CrB), a so-called cataclysmically variable star located about 2,700 light-years away from us, becomes over a thousand times brighter about every 80 years - a phenomenon known as a recurrent nova. The US space agency Nasa points out on its website: “This could be a once-in-a-lifetime observation opportunity.”
A nova occurs when a thermonuclear ignition occurs on the surface of a white dwarf star (left). In the case of T CrB, this is caused by a very close red giant. (Artist's impression) © NASA's Goddard Space Flight Center
Experts predict that the star T CrB will change its brightness by September 2024 at the latest. Normally it has a brightness of magnitude 10 - which is too faint to be visible to the naked eye. During the nova, however, according to NASA, its brightness will abruptly increase to magnitude 2 - which is approximately the same as the brightness of the Polar Star.
Once the star T CrB reaches its maximum brightness, it will be visible to the naked eye for several days, according to NASA experts. With binoculars you could even observe the star for a little more than a week before it loses brightness again for the next 80 years or so.
Star T CrB consists of a white dwarf and a red giant
But how is it that a star can increase its brightness so drastically and reliably, without external influences? The secret of T CrB lies in its nature as a binary star system. It consists of a white dwarf star and a red giant. The red giant becomes unstable due to rising temperature and high pressure and begins to shed its outer layers.
My news
Putin spokesman threatens NATO: “At the level of direct confrontation” read
Many pensioners are entitled to more pension points - but these are only available upon application
F-16 fighter jets shot down: Putin openly threatens to attack NATO airfield
German grocery chain is insolvent: read “Moral apostles who want to save the world”.
ARD documentary ruthlessly covers Germany's Leopard 2 problem for the Bundeswehr
Satellite images reveal: Russia is arming Black Sea ports against drone surveillance
The white dwarf is close enough to collect this material on its surface. About every 80 years, the white dwarf's atmosphere heats up so much that thermonuclear self-ignition occurs. The star becomes significantly brighter and appears from an earthly perspective as a “new star” in the sky – a nova.
How a Nova Forms: Thermonuclear Ignition of the White Dwarf Star
Jonathan Blazek, an astrophysicist at Northeastern University in Boston, explains: "The white dwarf is much smaller and more compact, so a small disk of hydrogen and perhaps some helium forms on the white dwarf." The expert continues: “Eventually enough of it builds up and ignites. It is not a literal burning in the sense of a fire, but a thermonuclear burning where hydrogen undergoes a fusion reaction.”
To observe the “new star” in the sky, you have to locate the constellation Northern Crown. It is a small semicircle of stars between the constellations Hercules and Bear Guardian (Bootes). The brightest star in this constellation, called Gemma or Alphekka, has a brightness of about magnitude 2.2. The nova will therefore shine brighter than the brightest star in the constellation for a short time.
A nova is expected to appear in the constellation Corona Borealis (Northern Crown) in 2024. (Artist's impression) © imago images/YAY Images
How to observe the nova in the constellation Northern Crown
Although a dark night sky is beneficial for many sky observations, in the case of the nova, a slightly brighter sky can actually be helpful, says Blazek. "Of course, if you go to a dark place you'll have a better view, but if you go to a dark place you'll see a lot of stuff up there." He recommends: "If you want to find it easier, you should go to one stay in a bright place. Then you only see the really bright things that stand out behind the glow of the city.”
Where the term “Nova” comes from
The term “Nova” comes from the Latin “stella nova”, new star. The famous Danish astronomer Tycho Brahe coined it when he saw a “new star” appear in the sky in 1572. We now know that it was a supernova - the explosion of a dying star. At the time we didn't know this - every star that appeared "suddenly" was a "nova".
Until the middle of the 20th century, the term “nova” was used for any type of outburst in the brightness of a star. Today we know more precisely what happens when a star “suddenly” appears. Since then, the term “nova” has only meant the ignition of a thermonuclear reaction on the surface of a white dwarf star.
The Northern Crown constellation will always be visible in the night sky of the Northern Hemisphere at some point in the coming months - depending on what time of day you look for it. To determine the current rising and setting times of Corona Borealis, rotating star maps or star map apps are helpful. In the latter you can enter the observation location and time and receive a current sky map on which you can search for constellations.
(tab)
The editor wrote this article and then used an AI language model for optimization at her own discretion. All information has been carefully checked.
Learn more about our AI principles here
.