Betelgeuse is one of the largest stars visible to the naked eye, often categorized as a red supergiant due to its immense size and reddish hue. Its prominence in the night sky makes it an excellent starting point for anyone looking to connect with the cosmos. Locating this star involves finding its host constellation and then using a technique called star-hopping to pinpoint the star itself.
Identifying the Constellation Orion
The search for Betelgeuse begins with locating the constellation it resides within, Orion, often called The Hunter. Orion is one of the most recognizable patterns in the night sky because of its distinct shape. The constellation is anchored by Orion’s Belt, a signature line of three bright stars: Alnitak, Alnilam, and Mintaka. These stars appear equally spaced and form a nearly straight line.
The Belt serves as the central reference point for the figure. From the Belt, the shape of the Hunter extends outward, outlined by four other bright stars. Two stars form the shoulders, and two more mark the feet of the figure.
Seasonal Visibility and Hemisphere
Orion is most easily visible during certain times of the year. For observers in the Northern Hemisphere, the constellation is best viewed during the late autumn, throughout the winter, and into the early spring months. It is visible for much of the night during this period, reaching its highest point in the sky around midnight in December.
Because Orion is positioned along the celestial equator, the imaginary line that projects Earth’s equator into space, it is visible to nearly all inhabited areas of the world. Viewing is possible between mid-September and mid-March for almost all locations. While the viewing angle differs slightly, people in both the Northern and Southern Hemispheres can easily see Betelgeuse rise in the eastern sky.
Navigating the Sky to Pinpoint Betelgeuse
Once Orion is located, finding Betelgeuse requires a directional step from the distinctive Belt. Betelgeuse marks the right shoulder of the figure of Orion the Hunter. When facing the constellation as it appears in the sky, Betelgeuse is the bright star positioned above and to the left of the Belt’s three-star line.
This star-hopping technique uses the Belt to locate surrounding stars. The star at the opposite shoulder, Bellatrix, is positioned above and to the right of the Belt. Betelgeuse and Bellatrix form the upper corners of the main figure, while the bright star Rigel marks one of the Hunter’s feet.
Confirming Betelgeuse by Color and Size
Confirming the identity of the star involves observing its distinct visual characteristics. Betelgeuse is easily discernible with the naked eye due to its deep reddish-orange color. This coloration stands in stark contrast to the brilliant, blue-white light of Rigel, the star marking the Hunter’s opposite foot. The difference in color helps to confirm that the correct star has been located.
This reddish hue is a direct result of the star’s classification as a red supergiant. Betelgeuse is a massive, aging star that has expanded and cooled significantly. Its immense size is a defining characteristic, with an estimated radius that is roughly 700 to 800 times that of the Sun. If placed at the center of our solar system, the star’s surface would extend past the orbit of Mars and potentially reach the orbit of Jupiter.