Scientists using the Hubble Space Telescope released a stunning new image of a fast-burning star to commemorate the iconic observatory’s 31st anniversary.
AG Carinae is a Luminous Blue Variables star that appears to be surrounded by a massive shell of material that the star blew into space thousands of years ago.
According to the European Space Agency, which helps run Hubble, the shell, called a nebula, is 5 light-years wide, around the distance between Earth and the closest star beyond our sun, Alpha Centauri.
It’s about 20,000 light-years away. It’s not just a bright spot in the sky; it’s a glowing gas-and-dust nebula fighting to keep itself from exploding.
The star began forming about 10,000 years ago through an eruptive phase and is expected to last just a few years, compared to our Sun’s nearly 10-billion-year lifespan.
“I like studying these kinds of stars because I am fascinated by their instability,” Kerstin Weis, who studies luminous blue variable stars at Ruhr University in Bochum, Germany, said in a NASA statement. “They are doing something weird.”
The Hubble Space Telescope was launched on April 24, 1990, and is still in use, capturing breathtaking celestial images. The AG Carinae is one of the largest and brightest stars in the galaxy.
NASA tweeted an image taken in ultraviolet light, which provides a much clearer picture of the star’s dust structures. Hubble is well-suited to observations of ultraviolet light.
The image got a lot of praise soon after it was released, with some users also thanking NASA.
In the new image, hydrogen and nitrogen gases glow red, while filamentary dust structures illuminated by the star glow blue. Hubble examined the scene in both visible and ultraviolet light.
NASA describes these stars as having a dual personality and calls them the luminous blue variables. They are inactive for a long time before erupting in an impatient outburst. These stars get even brighter during one of these outbursts — scientists say that AG Carinae shines about a million times brighter than the sun right now.
According to the ESA comment, the outbursts are a strategy to hold the star intact. The internal pressure of gravity and the external pressure of the star’s radiation usually balance inside a star, but in an unstable star, one can often win out over the other.
These stars are continuously fighting to maintain equilibrium between the radiation pressure bound outward and gravity pushing in due to their size and extremely hot temperatures. Radiation often triumphs, causing the star to explode in a volcanic eruption. These stars regain some composure after the outburst and become quiet for a while.
According to NASA, AG Carinae has also gone through this phase of two forces pushing it in opposing directions, but its outbursts have been less aggressive than its peers.
The luminous blue variables are important to astronomers because they have far-reaching effects on their surroundings, but they’re hard to come by: only around 50 have been discovered. These stars are in this process for thousands of years, and many of them die in titanic supernova explosions, enriching the universe with heavier elements than iron.