The Hubble Space Telescope just captured some stunning images of one of the rarest sights which can occur in the vast emptiness of space. One of our neighboring stars just threw one of its “infamous temper tantrums.” AG Carinae is an interstellar “rock star” with the “live fast, die young, and be a good looking corpse” kind of attitude. Astronomers call it a “blue giant.” It’s right around 20,000 light-years from Earth but it’s still in our Milky Way galaxy.
Hubble celebrates milestone
In honor of the Hubble Space Telescope’s 31 year anniversary, launched into orbit April 24, 1990, the team focused on catching one of AG Carinae’s periodic “outbursts.”
The star is so large and bright it’s easily seen with the naked eye. In fact, its “one of the brightest stars in our galaxy.” The light it pumps out is equal to “the light of 1 million suns.”
AG Carinae is huge, about 70 times more massive than our sun, “Sol.” These types of unstable stars are rare, only around 50 of them have been counted “across the Milky Way and its neighboring galaxies.” Hubble tuned in to catch one of the star’s schizophrenic battles with itself between brilliance and suicide. The brilliant blue light the star emits comes at the cost of incredible amounts of energy.
The pressure of radiation makes the star “lash out,” expanding “in size and releasing its outer layers into space.” After the radiation fueled explosive binge comes the inevitable collapse. The weight of the star itself is collapsed back inward by gravity.
One day, Hubble will get a really spectacular photo when the pressure of the radiation emitted from the star’s core won’t hold up against the collapsing gravitation.
Then, it will go supernova and explode in a final blaze of glory. Meanwhile, it breathes with the fury of massive radiation and collapses back in about once or twice a year.
A shell 5 light years wide
Hubble gets such impressive images of the star because of the glowing gas and dust shell all those eruptions create. One that happened 10,000 years ago was so massive that it produced the big shell of dust and gas.
It would take every atom in 10 of our suns to create just the shell. It’s hard to tell scale in space but it takes light a full five years to get from one side of the shell to the other.
“Luminous blue stars” like this one have a “convulsive” and short life span. We can expect Sol to keep shining bright for around 10 billion years.
AG Carinae could go supernova at any time. It’s already reached the end of it’s lifespan at “a few million years old.” That means Hubble could get that image before it’s retired.
Astronomers love working with stars like these. One Hubble astronomer, Kerstin Weis, notes “I like studying these kinds of stars because I am fascinated by their instability. They are doing something weird.” He watches them from Ruhr University’s Astronomical Institute in Bochum, Germany.
The latest image is described by the NASA team. The “red material is a glowing mixture of hydrogen and nitrogen gas. The blue structures are clumps of dust that are reflecting starlight.” They took images in “both visible and ultraviolet light, which reveals the intriguing structures around the star in great detail.”