Incredibly powerful megaflares from young stars are common, study shows

ref - X-ray Super-Flares From Pre-Main Sequence Stars: Flare Energetics And Frequency,, 11-May-2021.

My observation. The 36-page arXiv PDF ( reports “Table 1. MYStIX and SFiNCs Regions”, indicates distances reported 296 pc to 2800 pc in the survey. The PDF report states on page 24, “A similar calculation by Johnstone et al. (2019) suggests even faster destruction of early planetary atmospheres. Considering the effects of extreme ultraviolet irradiating planets around a ∼ 100 Myr solar-mass star, they find removal of even heavy-element atmosphere on timescales of ∼ 0.1 Myr by photodissociation and/or hydrodynamic escape. The addition of the super/mega-flare X-ray emission component would further shorten this atmosphere evaporation process. If the disk gas is removed after ∼ 5 Myr, the young planets will experience roughly one billion flares with energies 34 < log(EX) < 38 erg, including several million mega-flares with energies 32.6 < log(EX) < 38 erg.” My note. 10^34 to 10^38 erg energy levels here.

Another item on the list for defining and constraining habitable exoplanets today and Earth during their origin.


"There never was a good war, or a bad peace."
"a steady pulse of powerful flares can destroy a planetary atmosphere, and even shorten the lifespan of a planet itself."

This is yet another factor which is ignored when we get those merry monologues about humans colonising the Universe ;)
We have established the minimum 400+ year journeys to get there - now we have to carry heavy (lead?) shielding against this type of radiation. If it can destroy a planetary atmosphere, what can it do to an unshielded spaceship?

Cat :)
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