The mystery of the darkening of Samsara has been solved, but to the dismay of astronomers

The Sensui IV saga has been going on for almost a year. When the bright star began to dim suddenly, dropping to 40 percent of its regular brightness, astronomers held their breath, secretly hoping that the star would explode before our eyes, forming a giant supernova.

To this day, Sensua IV still shines at its usual brightness, but a mystery remains: scientists are still unsure what caused the sudden drop in brightness in the first place.

However, new observations from the Hubble Space Telescope may finally solve this strange mystery. The finding was published in a study in the Astrophysical Journal on Aug. 13, 2020.

Based on data recorded by NASA's Hubble Space Telescope, researchers hypothesize that the red supergiant's dimming may be due to a sudden ejection of massive amounts of hot material that blocked the star's light from reaching Earth.

This image shows the outburst of material blocking the light from Sensui IV from reaching Earth

The issue of the motion cycle - the results rely on Hubble observations that began in January 2019 and lasted several months. Hubble captured signs of densely heated material moving through the star's atmosphere in September, October, and November 2019, according to NASA.

In December 2019, astronomers began noticing that Sensua IV was starting to lose its signature brightness. By January 2020, Sensua IV's brightness faded by 25 percent, and by February, the star's brightness was reduced to 40 percent of its normal brightness, according to the Astronomer's Telegram.

Mystery solved

"With the Hubble Telescope, we can see images of matter leaving the surface of a planet and emanating into the atmosphere, even before the dust that causes stars to become dull forms." First author Andrea Dupree, a senior Astrophysics Research Center astrophysicist, explained in a statement that "we can see signs of dense, hot regions in the southeast of the star moving outward."

The hot, dense material crosses the visible surface of Sensui IV and reaches millions of miles from the star. At such distances, the material cools enough to form dust, according to the researchers.

The researchers are not yet sure of the cause of the outburst, but they believe it may be related to the motion cycle of Sensui IV.

The new study is somewhat consistent with observations made in February by the Lowell Observatory in Arizona, which suggest that Sensua IV's signature bright light was temporarily blocked from our view by material released from the star in the form of a dust cloud.

An example of Sensua IV - Sensua IV is a giant red star in the constellation Orion. It is a variable star, meaning that its brightness varies regularly between +0.0 and +1.3.

Even before it began to fade, Sensua IV was already popular among skywatchers for its brightness. However, while there is talk of its dimming, astronomers and the public alike hope to witness the explosion of this massive star.

As a star nears the end of its life, it runs out of fuel and collapses under its gravity. The death of a giant star leads to a huge explosion that spans the galaxy, which is called a supernova.

Astronomers can only observe faint supernovae in distant galaxies. Because of their great distance, these supernovae can only be detected long after the star has exploded. But Sensui IV is right in the middle of our cosmic forest - and being so close to the star means that scientists can observe the whole process from start to finish with unprecedented detail.

To everyone's disappointment, however, hopes for a huge explosion in the sky were dashed when Sensua IV began to glow again in late February.

But astronomers are still curious about what happened to the star, and why it lost its brightness. It is important to understand the answer to this question. If a star is about to be destroyed before our eyes, it can help astronomers better understand the life cycle of a star.

"No one knows what happens to a star before it goes supernova because this landscape has never been observed," says Dupree. "Astronomers may have sampled the star a year before they went supernova, not days or weeks before it happened. But the chances of the star going supernova very quickly are very small."