Betelgeuse Lets One Rip In Sharpest Image Ever

This orange blob shows the nearby star Betelgeuse, as seen by the Atacama Large Millimeter/submillimeter Array (ALMA). This is ALMA’s first-ever observation of the surface of a star and the highest-resolution image of Betelgeuse ever made. Two large, hotter areas are seen — a giant bubble of gas boiling up into the star’s atmosphere and the large bright patch near the top. Credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella

Infamously located in the armpit of Orion,  cherry red Betelgeuse is some 1,400 times larger than the sun and one of the largest stars currently known. Just so you know, the size of Betelgeuse depends up the color or wavelength of light in which it’s photographed. This latest picture was made by the ALMA array in Chile, which examines the sky in “millimeter and submillimeter light” located just beyond the infrared end of the color spectrum. Millimeter light waves are about the size of raindrops. In visible light, the star appears a little smaller, about 900 times the sun’s size. I’m still impressed.

This image, made with ALMA , shows the red supergiant Betelgeuse compared to the solar system. Betelgeuse would engulf all four terrestrial planets — Mercury, Venus, Earth and Mars — and even the gas giant Jupiter. Only Saturn would be beyond its surface. Credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella

Big stars burn their fuel faster than little ones, the reason Betelgeuse is just 8 million years old and on the verge of becoming a supernova. Smaller stars live for many billions of years. The sun’s been around for about 5 billion years and has enough nuclear fuel for at least another 7 billion. When the day comes that Betelgeuse goes supernova, the explosion will shine at least as bright as the half-moon and be easily visible in daylight. I hope you’re around for it.

Could you cook a mean pasta at Betelgeuse? Maybe. Boiling water creates rising bubbles the same way hot gas form plumes in Betelgeuse’s atmosphere. Credit: cyclonebill / CC BY-SA 2.0

We see Betelgeuse in the late stage of its life, when it expands in size and at the same time expelling gas and dust into space at the prodigious rate of about one solar mass — that’s the mass of our sun — every 10,000 years! Material leaves the star through the vigorous up and down movements of giant bubbles of gas in the star’s atmosphere called convection. They’re powered by the tremendous heat rising up from inside the star’s core. The same process happens when you boil water in a pot.

The red supergiant star Betelgeuse in Orion is one of a very few for which we have true images. Left photo taken in ultraviolet light by the Hubble Space Telescope shows a somewhat misshapen sphere. Right photo made by the ESO’s Very Large Telescope in near-infrared light and shows the star’s extended atmosphere and plume of surrounding gas. Credit: NASA/ESA (left) and ESO

In the new picture, ALMA observes the hot gas of Betelgeuse’s chromosphere, a layer of its atmosphere just above the star’s surface. Local differences in temperature here give the star an out-of-round appearance. With the European Very Large Telescope, astronomers have also found a huge bubble of blazing gas on the surface of Betelgeuse and a vast plume of gas and dust as large as the solar system ejected by the star.

If we could remove the atmosphere and face south at 1 p.m. local daylight saving time today, we’d see Betelgeuse about two fists south of the sun. By August, the sun will have moved far enough out of the picture to the east (left) that Orion will reappear in the dawn sky. Created with Stellarium

Since it’s summertime, Betelgeuse is in the daytime sky, but will return at dawn in August. It’s fun to think that if Betelgeuse exploded as a supernova in summer, we’d still see shining brightly!