Radical new findings by astronomers studying one of the brightest stars in the night sky may soon change how we look at Betelgeuse. Positioned in the so-called armpit of the constellation Orion, Betelgeuse has fascinated amateur stargazers and professional scientists for generations. Direct observations of this red supergiant, the Sun’s nearest such cousin, found that it was not a lone star. This companion orbits in a remarkably close orbit. The discovery explains the star’s odd color-changing pattern of fluctuating brightness and paves the way for new types of astronomical research.
Betelgeuse has fascinated stargazers for thousands of years, its characteristic red color rendering it one of the most recognizable stars to the unaided eye. This extreme star is one of the most important examples of a star that varies greatly with time, exhibiting a six-year cycle of variability. Scientists have long insisted on attributing the cause of these fluctuations. Many have speculated that a nearby companion star may be heating it up, allowing it to emit the surprising luminosity.
Discovery Using Advanced Technology
Astronomers identified the companion star with the ‘Alopeke instrument. This formidable scientific instrument is installed at the International Gemini Observatory’s (the Gemini Partnership’s) flagship telescope, the Gemini North telescope on Maunakea, Hawaii. This sophisticated technology enables astronomers to obtain extreme high angular resolutions and contrasts, essential for the detection and characterization of faint exoplanets and distant celestial bodies.
Howell, an astronomer who played a key role in the discovery, acknowledged how impressive this technological feat truly is.
“Gemini North’s ability to obtain high angular resolutions and sharp contrasts allowed the companion of Betelgeuse to be directly detected.” – Howell
The newly identified companion star is four times farther away from Earth than the Earth is from the sun. This exceptional closeness makes clear just how related it is with Betelgeuse. This close proximity has led astronomers to rethink models of stellar behavior and interactions in binary systems.
Characteristics of the Companion Star
The companion star has a mass about 1.5 times that of the Sun. In the optical wavelength region, it appears six magnitudes fainter than Betelgeuse. This is further evidence that the star is an A- or B-type pre-main-sequence star. It is a very hot, young, blue-white star that hasn’t initiated hydrogen burning in its core yet. Those attributes combined render it an interesting object of study, worthy of examination.
Betelgeuse’s volume is just as impressive, its radius measuring about 700 times that of the Sun. The extreme size of Betelgeuse contributes to its brightness and variability. This establishes an incredibly stimulating corner for further investigation into the physical interplay between Betelgeuse and its companion.
Implications for Future Research
The broader implications of this finding reach beyond Betelgeuse itself. Martin Still remarked on the broader significance of the findings:
“The speckle capabilities provided by the International Gemini Observatory continue to be a spectacular tool, open to all astronomers for a wide range of astronomy applications. Delivering the solution to the Betelgeuse problem that has stood for hundreds of years will stand as an evocative highlight achievement.” – Martin Still
Astronomers are prepared to explore these exciting new binary systems. They’ll be looking to see how these same dynamics affect other stars at earlier and later stages of their life cycles.
“This detection was at the very extremes of what can be accomplished with Gemini in terms of high-angular resolution imaging, and it worked. This now opens the door for other observational pursuits of a similar nature.” – Howell
Astronomers are now poised to explore additional binary systems and investigate how similar dynamics may influence other stars in various stages of their life cycles.
