Sunday, April 2, 2023

3941 - RED DWARF WITH PLANETS?

 

-   3941 -    RED  DWARF  WITH PLANETS?     Astronomers have been excited that some of Trappist-1's seven rocky planets could be habitable.  The James Webb Space Telescope has measured the temperature of a rocky exoplanet for the first time, finding that a "cousin" of Earth most likely lacks an atmosphere.



------------  3941  -  RED  DWARF  WITH PLANETS? 

-    When the Trappist-1 system was discovered in 2017, astronomers were excited at the prospect that some of its seven rocky planets, which are roughly similar to Earth in size and mass, could be habitable.

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-   Just 40 light years from Earth, the planets orbit much closer to their ultracool red dwarf star than the rocky planets in our Solar System. But their star gives off far less energy than our Sun.

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-   The system made an obvious target for the Webb telescope, which has unleashed a torrent of scientific discovery since releasing its first observations in July last year, 2022.

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-    Astronomers focused on Trappist-1b, the closest planet to the red dwarf, because it was the easiest to spot.  Webb's Mid-Infrared Instrument (MIRI) measured the change in brightness when the planet moved behind its star, in what is known as a secondary eclipse.

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-   Just before disappearing behind the star, the planet gives off the most light because it almost exclusively shows its 'day' side.   By subtracting the brightness of the star, the researchers calculated how much infrared light the planet was giving off.

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-    The MIRI instrument was able to act like "a giant touch-free thermometer.  'Perfect for baking pizza'.  The planet's dayside temperature was determined to be 450 Fahrenheit.

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-    The scientists therefore concluded that Trappist-1b has little or no atmosphere.  Other wavelengths would need to be analyzed to confirm this result.  But, it was certain that the atmosphere did not contain carbon dioxide, because that would have absorbed some of the light.

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-    The ability to analyze the potential atmospheres of such rocky exoplanets opens "a new era" in the study of planets outside our Solar System.  It was already known that Trappist-1b was uninhabitable, as it is too close to its star.  But Trappist-1e, Trappist-1f and Trappist-1g are all thought to be in what is called the "goldilocks zone".

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-    Planets in this zone have a moderate temperature which could support liquid water considered essential for life anywhere

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                   April 1, 2023       RED  DWARF  WITH PLANETS?              3926                                                                                                                          

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--------------------- ---  Sunday, April 2, 2023  ---------------------------

 

 

 

 

         

 

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