It's on the verge of death, a huge red ball of flame, glaring like a baleful, bloodshot eye, before it winks out into a tiny pinprick.

Betelgeuse was not always like this. The star used to be a main-sequence monster, a blue-white O-type star, the most massive stellar weight class. It would have turned a golden hue as it reached the end of this live-fast-die- young lifestyle. Astronomers have figured out how recent this was.

Around 2,000 years ago, the star would have been yellow-orange in color. For a star with as short a lifespan as Betelgeuse, the transition to its current ruddy shade was instantaneous.

It's not just to measure the duration of the transition. It has allowed an international team of scientists to make a new estimate of the star's age and give us a new timetable for its inevitable supernova.

A giant star at the end of its life is Betelgeuse, which is 700 or so light-years away.

The fusion of hydrogen in the core of a star is what powers that star throughout its life. The fusion of carbon and oxygen within the star has caused it to grow to gargantuan size.

The star will most likely collapse into a neutron star once it runs out of material.

The star has been the subject of tabloid scaremongering, stating that Betelgeuse could blow any day now, and we are all going with it. It will not and we are not.

We don't know when Betelgeuse's demise will happen, but we know that it isn't imminent. How long had it puffed up into a giant? Around 40,000 years ago, the best estimate was made.

We don't need to rely on our observations anymore. Humans have been recording the sky for thousands of years.

Historical records were searched for references to the star. They discovered them. Astronomers used to refer to Betelgeuse as yellow.

The star was described as being yellow in hue by a Han Dynasty court astrologer. The stars were described as white, blue, and red respectively.

It wouldn't be described as yellow if Betelgeuse was the same color.

Neuhuser says that it is possible to conclude that Betelgeuse was in color between the red and blue ships.

Around 100 years later, there was a Roman scholar who wrote a work called De Astronomia.

"Solis stella... corpore est magno, coloure autem igneo, similis eius stellae quae est in humero DEXTRO IONis." The sun's star is bright, fiery, and similar to the one in the right shoulder of the constellation Betelgeuse.

The color of Betelgeuse is more tawny than the color of the Sun and the color ofSaturn. The researchers say that the stars described by these observers are given accurate colors.

There is a way to trace the changing color of Betelgeuse. According to Tycho Brahe, by the 16th century, Betelgeuse was more red than Aldebaran. It's still red, but it's closer in hue to antares.

The researchers were able to estimate Betelgeuse's age and how long it has left before it goes kaboom because of this transition.

Neuhuser says that it has 14 times the mass of our sun and that it changed in color within two millennia.

The Betelgeuse is 14 million years old. It will explode as a nova in 1.5 million years.

We will be enjoying our red friend for a while.

The research has been published in a journal.