Today, it’s thought stars can’t be more massive than 150 times our sun’s mass. But, for a while, scientists thought they had found something even bigger in the star cluster Pismis 24.
Pismis 24 lies 8,000 light-years away in the direction of the constellation Sagittarius. A star in its midst – Pismis 24-1 – was thought to be 200 to 300 times our sun’s mass. But, in 2007, this object was revealed to be not one but three stars, orbiting each other.
EarthSky spoke with Jesus Maiz Apellaniz, an astronomer with the Andalucia Institute of Astrophysics in Spain. Maiz Apellaniz said that stars like those in this system are bright, a million times or more brighter than our sun. But this sort of star can be hard to find. They’re short-lived and far away, in this case about 8,000 light-years from Earth.
He added that the birth place for stars are usually clouds that have large amounts of dust, and dust obscures the light from the stars and makes them very hard to detect.
Each of the stars in Pismus 24-1 are still very massive, between 60 and 100 times as massive as our sun. But theories suggest that a star can’t be more massive than 150 solar masses.
With this system now known to be several stars instead of one, the star “Eta Carinae” remains a good candidate for the title of most massive star known. It’s somewhere around the theoretical mass limit of 150 solar masses.
In your “Shedding Light …” article, you describe Pismis 24 as a double star under the picture, “three” stars orbiting each other in the first paragraph and “four” stars in the last two paragraphs.
So, please shed more light on the CORRECT number of stars in old Pismis 24.
Nelson, thank you! The caption wasn’t complete. I made it more complete. As for the problem between “three” vs. “four” in the script itself … Joel and I mis-spoke. I’ve corrected the error in the transcript, but you can still hear us saying the wrong thing in the audio version (which can’t be corrected at this point).
We apologize.
Our thanks to you for catching this error.
Deborah
GR8
The Pismis stars and Eta Carinae are not the largest stars known. The star Vy Canis Majoris , recently discovered , is approximately 500,000 times bigger then our own sun. That is about 100,000 times more then scientists think of how big a star can get , thus flinging that theory out of the water.