Betelgeuse, also known as Alpha Orionis or Alpha Ori, is the second-closest red supergiant to Earth. From November 2019 to March 2020, this star experienced a historic dimming of its visible brightness. Usually having an apparent magnitude between 0.1 and 1, its visual brightness decreased to 1.6 magnitudes around 7-13 February 2020 — an event referred to as Betelgeuse’s Great Dimming. New research shows that the observed dimming is probably caused by an unseen companion star orbiting Betelgeuse. Named Alpha Ori B, or the Betelbuddy, this companion acts like a snowplow as it orbits Betelgeuse, pushing light-blocking dust out of the way and temporarily making Betelgeuse seem brighter.
Betelgeuse, the second brightest star in the constellation Orion, is an 8-million-year-old red supergiant located approximately 724 light-years away from Earth.
With a radius around 1,400 times larger than the Sun’s, Betelgeuse is one of the biggest stars known.
It is also one of the most luminous stars known, emitting more light than 100,000 Suns.
The star is nearing the end of its life span, and when it explodes, the event will be bright enough to see during the day for weeks.
Astronomers can predict when Betelgeuse will explode by effectively ‘checking its pulse.’
It’s a variable star, meaning it gets brighter and dimmer, pulsing like a heartbeat.
In Betelgeuse’s case, there are two heartbeats: one that pulses on a timescale a little longer than a year, and one that pulses on a timescale of about six years.
One of these heartbeats is Betelgeuse’s fundamental mode, a pattern of brightening and dimming that’s intrinsic to the star itself.
If the star’s fundamental mode is its long-scale heartbeat, then Betelgeuse could be ready to blow sooner than expected.
However, if its fundamental mode is its short-scale heartbeat, as several studies suggest, then its longer heartbeat is a phenomenon called a long secondary period.
In that case, this longer brightening…
Read the full article here
