Betelgeuse is located within the Milky Way Galaxy, our home spiral galaxy. This brilliant celestial object is one of the most famous and recognizable stars visible in the night sky. It resides in the same stellar neighborhood as our Sun and is easily spotted by its distinctive reddish-orange hue. It is typically counted among the top ten brightest stars seen from Earth. Betelgeuse is a massive member of the Milky Way, currently undergoing a dramatic stage of its stellar life.
Betelgeuse’s Location and Galactic Context
Betelgeuse is a relatively close neighbor, situated approximately 500 to 650 light-years from Earth. Precisely measuring its distance has been challenging due to its immense size and variable nature, leading to a range of estimates. This proximity places Betelgeuse firmly within the local spiral arm of the Milky Way, known as the Orion Arm, where our own solar system resides.
The star is an unmistakable feature of the Orion constellation, marking the hunter’s shoulder. The Milky Way is a massive barred spiral galaxy spanning over 100,000 light-years across. Betelgeuse is part of the galactic disk, sharing the flat plane of stars, gas, and dust that defines our galaxy. It is one of the most luminous stars in this local region.
The Nature of a Red Supergiant
Betelgeuse is classified as a Red Supergiant, representing a late phase in the evolution of massive stars. Its current state is a consequence of having exhausted the hydrogen fuel that powered its core fusion for millions of years. Once the hydrogen was depleted, the core contracted, causing the star’s outer layers to swell dramatically and cool.
This stellar expansion has made Betelgeuse one of the largest stars known, with a radius estimated to be 640 to 764 times that of the Sun. To grasp its scale, if Betelgeuse were placed at the center of our solar system, its outer edge would extend past the orbits of Mercury, Venus, Earth, and Mars. Its enormous size is coupled with a relatively low surface temperature of about 3,600 to 3,800 Kelvin, which is significantly cooler than the Sun’s surface. This lower temperature is the reason for its distinctive reddish-orange color.
Why Betelgeuse Captures Attention
Betelgeuse draws significant attention due to its volatile nature and predicted fate. As a red supergiant, it is nearing the end of its life and is destined to explode in a catastrophic event known as a Type II supernova. On a cosmic timescale, this explosion is expected to occur relatively soon, likely within the next 100,000 years.
The star captured global headlines during late 2019 and early 2020 when it experienced an unprecedented dimming event. This sudden drop in brightness was not an immediate precursor to a supernova, as some speculation suggested. Observations revealed the dimming was caused by the ejection of hot plasma from the star’s surface, which cooled and condensed into a large cloud of dust.
When the star finally explodes, it will become an incredibly bright, temporary beacon in the sky. The supernova is predicted to shine as brightly as the half-moon for several months, making it visible even during the daytime. Due to its distance of over 500 light-years, the explosion is far enough away to pose no danger to life on Earth.