NASA's GALEX Spacecraft Observes Effects Of Red Dwarf Flares On Orbiting Planets
Currently, scientists are hunting for cool dwarf stars wherein exoplanets exist in habitable zones. The finding of these exoplanets like the TRAPPIST-1 and LHS 1140 systems shows that Earth-like alien worlds might surround billions of red dwarf stars in the Milky Way galaxy.
Like the Earth's Sun, countless of these stars eject strong flares. However, are red dwarfs truly as friendly to life as they seem to be? Or, do red dwarfs' flares cause the uppermost layer of orbiting planets un-inhabitable?
To know more about the answers to these questions, NASA's GALEX (Galaxy Evolution Explorer) spacecraft observes the rapid increases in the brightness of stars because of flares. As it is, flares produce radiation across broad wavelengths with notable fraction of their total energy released in the UV (ultraviolet) bands where the spacecraft observed. Meanwhile, the red dwarfs from where flares come from are proportionately dim in UV.
According to Clarksville Online, the disparity allows a team of scientists to calculate events with less total energy than many other flares detected previously. It is of great significance because smaller flares could be much more often and add up over time to develop an un-inhabitable environment.
Scott Fleming of the Space Telescope Science Institute (STScI) in Baltimore queried, "What if planets are constantly bathed by these smaller, but still significant, flares? There could be a cumulative effect."
Meanwhile, the first author of the study, Chase Million of Million Concepts in State College in Pennsylvania, noted that, "We have found dwarf star flares in the whole range that we expected GALEX to be sensitive to, from itty bitty baby flares that last a few seconds, to monster flares that make a star hundreds of times brighter for a few minutes."
The team has discovered dozens of flares while they search for several hundreds of red dwarf stars in the galaxy. The flares that the GALEX spacecraft uncovered are the same in strength to flares that the Earth's Sun produces.
NASA's GALEX is a space telescope that observes galaxies in UV light. It is launched on April 28, 2003, by a Pegasus rocket.