A simulated view of Betelgeuse that illuminates the surface of a distant, hypothetical planet [Michele Diodati]

All About Betelgeuse. How Far Is It?

Determining the exact distance of Betelgeuse has proved to be an extremely difficult task, so that, despite decades of studies, we still know the distance of this supergiant with a certain approximation

Knowing the exact distance of a star is essential to derive other important parameters, such as diameter and absolute magnitude. However, the precise determination of stellar distances is far from easy, especially when dealing with a supergiant like Betelgeuse, a star that has a much larger angular diameter than the parallax angle measurable from Earth and continuously varies in brightness and size.

Nothing more variable than the distance of Betelgeuse

Therefore, it happens that the uncertainty in the knowledge of the distance affects all the parameters that depend on it, starting with the stellar diameter. There is ample evidence of this uncertainty in numerous generalist sources that provide summary information on Betelgeuse. Here’s a little catalog of it.