After ESO’s telescope detects that a massive star “disappears,” scientists puzzled over what caused it.

FP TrendsJuly 03, 2020 11:13:52 IST

Scientists recently observed a star that appears to have disappeared. Using the Very Large Telescope (VLT) from the Southern European Observatory, the researchers discovered that a massive unstable star in a dwarf galaxy 75 million light-years away vanished without a trace.

Several teams of astronomers between 2001 and 2011 studied the mysterious massive star, located in the Kinman dwarf galaxy. They realized that the star was in the last stages of its useful life.

They wanted to find out how very massive stars end their lives, and the object on the Dwarf Kinman seemed like the perfect target. However, things took an interesting turn when they pointed ESO’s VLT to the distant galaxy in 2019. To their surprise, astronomers discovered that the star had disappeared.

The star study was led by PhD student Andrew Allan of Trinity College, Dublin, Ireland, and was published in Monthly notices from the Royal Astronomical Society.

An illustration of a luminous blue variable star as in the Kinman dwarf galaxy. Image credit: ESO / L. Calçada

According to the researchers, the star may have disappeared after becoming less bright and partially obscured by dust. They also said that it could have collapsed into a black hole without producing a supernova.

“If true, this would be the first direct detection of a monster star that ends its life this way,” Allan said.

The Kinman dwarf galaxy is located about 75 million light years away in the constellation Aquarius, making astronomers too far to see their individual stars, but they can detect the signatures of some of them, reported Daily science.

During their observations of the galaxy between 2001 and 2011, the scientists observed light from the galaxy that showed evidence that it harbored a ‘luminous blue variable’ star approximately 2.5 million times brighter than the Sun.

The study reports that stars of this type are unstable and show occasional dramatic changes in their spectra and brightness. Still, the luminous blue variables leave specific traces that scientists can identify. But, such traces were absent from the data they collected in 2019.

“It would be very unusual for such a massive star to disappear without producing a brilliant supernova explosion,” says Allan.

Researchers will take a closer look at the star’s fate once ESO’s Extremely Large Telescope (ELT) goes live in 2025. The ELT can capture high-resolution images, including very distant stars like those of Kinman Dwarf, located at more than 75 million light years away.