An image from the Heliospheric Imager aboard NASAs STEREO spacecraft shows the star Betelgeuse, circled around. For a number of weeks in 2020, STEREO was the only observatory making measurements of Betelgeuse since of the spacecrafts unique position in space. Throughout this observation gap in 2020, NASAs STEREO spacecraft– with measurements revealed in red– stepped in to observe Betelgeuse from its special vantage point, revealing unforeseen dimming by the star. During this duration in between late June and early August, STEREO observed Betelgeuse on five different days, rolling the spacecraft for about 2 hours each time to place Betelgeuse in the field of view of STEREOs Heliospheric Imager, an instrument usually utilized to record images of the Suns outflowing material, the solar wind, as it passes by the spacecraft and towards Earth. STEREOs measurements revealed that Betelgeuse is dimming again– an unexpected development so quickly after its last dim period.
An image from the Heliospheric Imager aboard NASAs STEREO spacecraft reveals the star Betelgeuse, circled around. For numerous weeks in 2020, STEREO was the only observatory making measurements of Betelgeuse because of the spacecrafts unique position in area. Credit: NASA/STEREO/HI
For numerous weeks in summertime 2020, NASAs Solar and Terrestrial Relations Observatory, or STEREO, had the planetary systems finest view of the star Betelgeuse, whose severe dimming over the previous a number of months has fascinated scientists. STEREOs measurements exposed more unanticipated dimming by the star, more including to the concerns around Betelgeuses recent behavior.
Beginning in late spring 2020, Betelgeuse has actually appeared near to the Sun in the sky because of Earths position in area. The STEREO spacecraft is currently about 70 degrees away from Earth– suggesting that in late June, STEREO was in approximately the very same position that Earth was in around mid-April, and might for that reason see the stars that appeared in Earths night sky during April.
This figure shows measurements of Betelgeuses brightness from various observatories from late 2018 to present. The green and blue points represent information from ground-based observatories. The spaces in these measurements take place when Betelgeuse appears in Earths day sky, making it impossible to take accurate brightness measurements. During this observation space in 2020, NASAs STEREO spacecraft– with measurements displayed in red– actioned in to observe Betelgeuse from its unique perspective, revealing unanticipated dimming by the star. The 2018 information point from STEREO was found in the objectives archival data and was used to adjust STEREOs measurements against other telescopes. Credit: Dupree, et al
. Researchers took benefit of this distinct orbital position to keep tabs on Betelgeuse while the star was invisible to Earth-bound observatories. Throughout this duration between late June and early August, STEREO observed Betelgeuse on 5 separate days, rolling the spacecraft for about two hours each time to put Betelgeuse in the field of view of STEREOs Heliospheric Imager, an instrument typically used to catch pictures of the Suns outflowing product, the solar wind, as it passes by the spacecraft and towards Earth. The group shortened the instruments direct exposure time to represent Betelgeuses relative brightness compared to the solar wind. The instruments large field of view covers about 70 degrees of sky, which enabled researchers to calibrate their measurements utilizing consistent stars in the night sky across a number of weeks.
STEREOs measurements exposed that Betelgeuse is dimming once again– an unanticipated advancement so right after its last dim duration. Betelgeuse usually goes through brightness cycles lasting about 420 days, with the previous minimum in February 2020, suggesting this dimming is happening suddenly early. These observations were reported by the science team by means of The Astronomers Telegram on July 28, 2020. When Betelgeuse returns to the night sky in late August, this is an intriguing phenomenon that researchers will study with extra Earth-orbiting and ground-based observatories.
This four-panel graphic shows how the southern area of the rapidly progressing, brilliant, red supergiant star Betelgeuse may have all of a sudden become fainter for a number of months during late 2019 and early 2020. In the very first two panels, as seen in ultraviolet light with the Hubble Space Telescope, a bright, hot blob of plasma is ejected from the development of a huge convection cell on the stars surface area. In panel 3, the outflowing, expelled gas rapidly broadens outward. It cools to form a massive cloud of obscuring dust grains. The final panel exposes the big dust cloud obstructing the light (as seen from Earth) from a quarter of the stars surface. Illustration credit: NASA, ESA, and E. Wheatley (STScI).
Is a Supernova Imminent?
The red supergiant is destined to end its life in a supernova blast. Some astronomers think the sudden dimming may be a pre-supernova occasion. The star is relatively nearby, about 725 light-years away, which suggests the dimming would have occurred around the year 1300. However its light is simply reaching Earth now.
Harvard & & Smithsonian (CfA), Cambridge, Massachusetts, discussed. “Astronomers have tested stars maybe a year ahead of them going supernova, however not within days or weeks before it happened. But the opportunity of the star going supernova anytime soon is pretty little.”.
Read Hubble Finds Cause for Betelgeuses Mysterious Dimming for more research on Betelgeuses recent dimming.