Scientists have recently provided a new explanation for the mysterious variations of Betelgeuse, a “cosmic monster” that is 1,400 times larger than the Sun.
A study published in the Astrophysical Journal indicates that the “cosmic monster” Betelgeuse – an object that has consistently baffled scientists – is actually a binary star system with significantly different sizes.
Betelgeuse is the second brightest star in the constellation Orion, shining with a luminance 100,000 times greater than the Sun and located 724 light-years away from Earth.
“Cosmic monster” Betelgeuse – (Photo: NASA).
Based on historical documents, scientists predict that it is about to explode into a supernova.
Specifically, over 2,100 years ago, the Chinese historian and scholar Sima Qian described the star Shen Shu Si – which refers to Betelgeuse – as having a bright yellow color, unlike the red hue of Antares in the Scorpius constellation.
However, around 2,000 years ago, the Roman scholar Hyginus described Betelgeuse as having an orange-yellow color, similar to Saturn. By the 16th century, Danish astronomer Tycho Brahe noted that Betelgeuse appeared redder than Antares.
Currently, Betelgeuse is classified as a red supergiant.
The color changes over time have led scientists to conclude that it is a star that has reached the final stages of a red giant and is on the brink of explosion.
However, the light signals from this cosmic monster, which is 1,400 times larger than the Sun, are quite unusual.
It has repeatedly brightened and dimmed, causing scientists to feel “a pang of anxiety” thinking that it was about to explode for several years.
As a result, it is classified as a variable star, with light fluctuations resembling a heartbeat. It also exhibits two “heartbeats”: one pulse on a timescale of just over 1 year and another on a timescale of about 6 years.
One of these pulses is the fundamental mode of Betelgeuse, a pattern of brightening and dimming intrinsic to the nature of the star. If this pulse is the 6-year pulse, Betelgeuse may explode sooner than expected.
However, if its baseline heartbeat is a shorter pulse, as some studies suggest, then the longer pulse could be a phenomenon known as a long secondary cycle, according to a research team led by astrophysicist Jared Goldberg from the Flatiron Institute (USA).
The authors indicate that in this scenario, the second heartbeat is due to an external influence, specifically a companion object.
“We have ruled out all intrinsic sources of variability that we could think of for why this brightening and dimming phenomenon occurs in this way” – Dr. Goldberg told Sci-News.
They have dubbed this companion object Betelbuddy, but they have yet to conclude what type of object it is. However, the most likely possibility is that it is a companion star with twice the mass of the Sun.
Dr. László Molnár, an astronomer at the Konkoly Observatory (Hungary) and co-author of the study, stated that they are investigating observational methods capable of thoroughly decoding the nature of this companion object.
