Thread

A 12-year sequence of telescope images of a star and four planets orbiting

402 points · 82 comments · mariuz

317070 · 1790968262 · focus · HN ↗
Wow, in terms of angle, how far are these planets separated from the star?
I always thought we would never be able to image something like that. The distances would be too small and the contrast too large to figure something at the resolution we can get on earth. I'll need to read up on how this was done.
1. ceejayoz · 1790968991 · focus · HN ↗
  <a href="https://en.wikipedia.org/wiki/HR_8799" rel="nofollow">https://en.wikipedia.org/wiki/HR_8799
  1. ryandrake · 1790969642 · focus · HN ↗
    Yea, the planets are gigantic, and in distant orbits from their star. I don't think we even have the ability yet to directly image exoplanets much smaller than, say, Saturn, or closer to their stars than Saturn.
  2. jcims · 1790969656 · focus · HN ↗
    TL;DR - Two inside (16, 26AU) and two outside (43, 69AU) Pluto's orbit (39AU). They are all estimated to be a bit bigger than Jupiter.
2. turtletontine · 1790971267 · focus · HN ↗
  The scale bar (20 AU) represents 20 time the distance between the Earth and the sun. This star is about 41 parsecs away, so the angular size of that scale bar is about half an arcsec. (One degree is split into 60 arcminutes, one arcminute into 60 arcseconds. Just like a clock).
  That angle is about the diameter of a US quarter coin seen from 11km (7mi) away.

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