In Space News:
It is was recently decided that the Arecibo Observatory in Puerto Rico is being decommissioned.
Space X crew launched a 6 month manned mission to the ISS.
Now on to the main topic; “The Dimming Stellar Giant — Betelgeuse.”
Introduction
Betelgeuse is a red supergiant about 550 light-years away from us.
It is about 18 times more massive, 760 times wider, and 100,000 brighter than our Sun.
Surface temperature is a cool 3600K compared to Sun 5800K. It is 8.0-8.5 Myr old compared to our Sun’s 5 Gyr.
Betelgeuse is a variable star (Semi-regular variable star). The primary pulsations repeat every ~425 days, but the star also shows additional changes in brightness with periods of 100-180 days and 5.9 years, it dims to less than half it’s maximum brightness (1 magnitude).
The Dimming Event
In late December 2019/ early January 2020, in its expected dimming cycle, Betelgeuse dimmed unusually far (1.3 magnitudes).
The unexpected dimming was probably caused by an immense amount of superhot material ejected into space. The material cooled and formed a dust cloud that blocked the starlight coming from about a quarter of Betelgeuse’s surface. (Read more about it here)
This dimming event re-ignited a conversation about a possible imminent supernova. If Betelgeuse does go supernova, it’ll be brighter than the Moon for about two months. It will be a spectacle to watch.