2018-03-27

the very local neighborhood

Today Jackie Faherty (AMNH) gave the astro seminar at NYU. She got us fired up about Gaia even before her talk, at lunch, where she said that on April 25 the curtains would finally open and we would get to see the Milky Way for the first time! Her seminar didn't disappoint: She pointed out that of the five closest stars to the Sun, three were discovered in 2014! And it appears that the Solar Neighborhood still has lots of secrets for us to discover. She also showed us a star that passed within 60,000 AU of the Sun some 70,000 years ago. That's interesting! If it disturbed comets onto elliptical orbits, we won't see their infall for a few million years! (Just a free-fall argument there.) That observation, combined with things people have found in Gaia DR1, suggests that we have a close encounter like that about once per million years.

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