In 2020, Betelgeuse dimmed to a level that had never been recorded before. This event is known as the “Great Dimming”. The dimming occurred when Betelgeuse ejected a large amount of material. 

Some astronomers believe that the dimming was caused by a burst of silicon monoxide dust from the star. This burst may have been caused by a sudden cooling of the star’s surface. 

The STELLA robotic telescope in Tenerife observed about 2,700 spectra over the past 15 years. These observations revealed the following: 

• The photosphere of Betelgeuse during the Great Dimming 
• The atmosphere of Betelgeuse before and during the Great Dimming 

Betelgeuse is the second brightest star in the constellation Orion. It’s one of the most luminous stars in the night sky. Its name comes from the Arabic term bat al-jawzāʾ, which means “the giant’s shoulder”.

Betelgeuse is a variable star, which means its brightness changes over time. Betelgeuse’s current magnitude is around +0.42. Its visual magnitude is 0.5, making it the 10th brightest star in the sky. 

Betelgeuse’s luminosity is about 14,000 Suns at maximum and 7600 Suns at minimum. It’s thousands of times brighter than the sun and about 700 times bigger. Betelgeuse is visible with the naked eye from Earth, but binoculars and small telescopes can enhance the view. 

Betelgeuse is an orange supergiant star located about 650 light-years away

Yes, Betelgeuse has been brightening again.  In May and June 2023, Betelgeuse’s brightness increased by almost 50%.  Some experts believe this is a rebound effect from the Great Dimming.  Others think the star might have entered its final life stage and might go supernova in the near future.  However, others predict that Betelgeuse will return to its usual ways within the next five to 10 years. 

The extreme brightening of Betelgeuse might be attributed to the same dust cloud that caused its previous dimming. This cloud could now be reflecting light from the star, making it appear brighter.

Betelgeuse is expected to explode as a supernova within the next 100,000 years. The supernova event could last a few weeks to a few months. 

Betelgeuse’s final fate depends on how much material is left after the supernova. If the remnants are less than 2-3 times the mass of our Sun, Betelgeuse will become a neutron star. If the remains are more massive, a black hole could form. 

Betelgeuse is only 10 million years old, which is 50 times younger than our sun. It has already run out of the hydrogen fuel in its core and is now in the final, red giant stage of its life.

The Great Dimming Event (GDE) was when the red supergiant star Betelgeuse visibly faded in late 2019 and early 2020. The star’s brightness dropped by about 60%. The dimming was noticeable with the naked eye. 

The GDE puzzled and fascinated the world. Some thought that the star, which is coming to the end of its life, was about to explode and go supernova. 

The star’s surface is now bouncing like gelatin on a plate, and it has lost the natural 400-day heartbeat that has been present for at least two centuries.

There are multiple theories about why Betelgeuse dimmed: 

• Surface mass ejection The star ejected a large amount of gas and dust, which is called a “surface mass ejection”. This was caused by an “anomalously hot convective plume”. 
• Dust cloud A dark spot in the star’s southern hemisphere lowered the temperature and caused a bubble of hot gas to form. As the gas cooled, it formed a dust cloud that blocked the star’s light. 
• Wandering companion A companion star may have swung close to Betelgeuse, causing a tidal bulge that dimmed the star’s surface. 

Other theories include: 

• A burst of silicon monoxide dust 
• A sudden cooling of the star’s surface 

Betelgeuse is a pulsating, semiregular variable star. It goes through cycles of increasing and decreasing brightness due to changes in its size and temperature.

Betelgeuse is a red supergiant star that’s about 15–20 times more massive than the sun. It’s located in the constellation Orion, about 500–600 light years from Earth. Betelgeuse is expected to go supernova and become a neutron star or black hole. However, this might not happen for at least 100,000 years

Betelgeuse has been shedding mass for the past 100,000 years.  It’s currently in the late stages of core carbon burning, which lasts about 1,000 years.  Some scientists believe that Betelgeuse has entered its final life stage. In May and June 2023, Betelgeuse’s brightness increased by almost 50%. 

When Betelgeuse does go supernova, the energy will have weakened significantly by the time it reaches Earth. Scientists estimate that a supernova within 25 light-years would not directly threaten Earth

According to astronomers at the Université Côte d’Azur, the dimming of the star Betelgeuse may have been caused by a burst of silicon monoxide dust. This burst may have been caused by a sudden cooling of the star’s surface

Before the dimming began, Betelgeuse expelled a large bubble of gas. This caused a star spot to form on the star’s surface, which cooled down the region. This cooling caused heavier elements like silicon to condense into dust

The cause of the dimming revealedThe French team also observed that while the star appeared dim during these years, its photosphere actually brightened up. This led the team to believe that the dimming was due to a burst of dust, in the form of silicon monoxide, coming from the star

The STELLA robotic telescope in Tenerife has observed about 2,700 spectra over the past 15 years. The spectra cover a wavelength range of 390–880 nm. The observations were made between 2008 and 2023. 

The STELLA robotic observatory is located at Izana Observatory in Tenerife, Spain. It has two 1.2m robotic telescopes. The telescopes monitor stellar activity using a high-resolution spectrograph. 

The STELLA robotic observatory was inaugurated in 2006. It is jointly operated by the Astrophysical Institute Potsdam (AIP) and the Instituto de Astrofísica de Canarias (IAC). 

The first stellar spectrum taken by STELLA-I was from the star α Tauri (K5III) on September 9, 2005. By mid September 2009, a total of 18,000 echelle spectra were obtained. (Full article source google)

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