December 2019 – WinStars 3

What’s going on with Betelgeuse ?

Have you noticed that Betelgeuse1, the star forming the right shoulder of the legendary hunter Orion, has recently lost its luster?

The light curves available on the American Association of Variable Star Observers (AAVSO) website confirm a change in magnitude from 0.5 to 1.3 in the space of few weeks. These changes in brightness are not so surprising for this red supergiant, twelve times more massive than our Sun, known for its variability and irregularity. But it is the brutality of this evolution that intrigues astronomers today.

We know that Betelgeuse is the closest candidate for a future supernova explosion in our galaxy. For this reason, it has been observed attentively for the last 50 years with the hope of learning more about the processes at work in the stars’ agony. Even if several scenarios can explain the abnormal decline of its luminosity, we obviously cannot exclude the fact that it is, perhaps, about to explode.

Each time WinStars starts, the program will consult the AAVSO data to reflect the evolution of the magnitude of Betelgeuse. We can already note that the star is not much brighter than its neighbour Bellatrix in the constellation of Orion.

Version 3.0.104 also features a slightly redesigned Animations dialog box. The slider has been replaced by a simple field in which the user can enter a multiplicative factor to speed up, or slow down, the normal rate of time flow.

A new icon will also appear in the right hand menu. It replaces the “point in a direction” icon which was not really needed and was not yet implemented.
It makes it possible to reverse the course of time…

1. The traditional name Betelgeuse is derived from either the Arabic إبط الجوزاء Ibṭ al-Jauzā’, meaning “the armpit of Orion”, or يد الجوزاء Yad al-Jauzā’ “the hand of Orion” (Sources: