The red supergiant Betelgeuse, one of the bright stars in the sky, has been the source of fascination in the last few years. New data from the Hubble Space Telescope shows that the star blew off a huge chunk of its mass in the year 2019.

A surface mass ejection is similar to the mass ejections seen in our sun and other stars but much, much bigger. The surface mass ejection created huge changes to the star's structure and behavior.

An illustration showing changes in the brightness of the red supergiant star Betelgeuse.
This illustration plots changes in the brightness of the red supergiant star Betelgeuse, following the titanic mass ejection of a large piece of its visible surface. The escaping material cooled to form a cloud of dust that temporarily made the star look dimmer, as seen from Earth. This unprecedented stellar convulsion disrupted the monster star’s 400-day-long oscillation period that astronomers had measured for more than 200 years. The interior may now be jiggling like a plate of gelatin dessert. NASA, ESA, Elizabeth Wheatley (STScI)

Hubble data was used along with data from ground-based telescopes to show how quickly the star's brightness changed as it threw off mass and formed a large dust cloud. There is a new insight into the lives of huge red stars like Betelgeuse, which is coming towards the end of its life and will eventually explode.

In a statement, Dupree said that they had never before seen a mass ejection of a star. We don't know what's going on. It is a completely new phenomenon that we can see directly with Hubble. We are watching evolution.

Dupree said that the event had left a mark on the structure of Betelgeuse, with the interior bouncing. The star's rate of brightness pulsation will be affected by the loss of the mass of matter that blew off the star. Scientists don't know how Betelgeuse will develop in the future after the star's 400 day cycle was disrupted.

There is a recommended video.