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A young planet whirling closely around a red
dwarf star is changing in unpredictable ways

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with each orbit.

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NASA’s Hubble Space Telescope observations
initially showed the planet wasn’t losing

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its atmosphere to its parent star.

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One and a half years later, Hubble observations
revealed clear signs that the star’s torrential

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blasts of energy, called a stellar wind, were
stripping the planet’s hydrogen atmosphere.

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These extreme changes between orbits, and
over such a short period of time, shocked

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astronomers.

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Red dwarfs are the most abundant stars in
our Milky Way galaxy, and they likely host

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most of our galaxy’s planets, but can these
planets be hospitable to life?

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These new Hubble results suggest that this
particular red dwarf may have sudden and extremely

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variable outbursts.

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Under these intense conditions, planets forming
within the first 100 million years of the

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red dwarf star’s birth should experience
the greatest loss of their atmosphere, possibly

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stripping it away completely.

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One possible explanation for the vastly different
Hubble observations is that the torrential

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stellar wind shapes the planet’s atmospheric
loss, sometimes making it observable and at

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other times not.

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It may even cause some of the outflow to “hiccup”
out ahead of the planet itself.

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Stellar models predict this hiccup, but Hubble
provided the first observational evidence

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of it happening and to an extreme degree.

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Thanks to Hubble, we’re learning more about
how planets form and survive around stars

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very different from our own, helping us uncover
the mysteries of the universe.

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Follow us on social media @NASAHubble