Tau.Neutrino said:
Freak “cosmic telescope” reveals most distant star ever observed
When it comes to viewing far-flung stars, astronomers are usually limited to studying them within groups – or galaxies – or as supernovae. But thanks to a rare cosmic alignment, astronomers have been able to view the most distant individual normal star ever observed. Located some 9 billion light years from Earth, the star was captured by the Hubble Space Telescope thanks to gravitational lensing amplifying the star’s feeble glow.
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> thanks to a rare cosmic alignment, astronomers have been able to view the most distant individual normal star ever observed. 9 billion light years.
Amazing.
(What’s it’s spectrum? LOL, Just kidding).
> they found the flickering light was coming from a single blue supergiant that has been dubbed Icarus, but whose formal name is MACS J1149 Lensed Star 1
They found its colour from just a flicker – that’s startling, darn good observing. Most flickers are cosmic rays hitting the optical sensor.
> Already, the light from Icarus has allowed scientists to discount one possibility for the explanation of dark matter – that it is mostly made up of a large number of primordial black holes with masses tens of times larger than the Sun lurking within galaxy clusters.
Um, not that I’m doubting them but, how is this ruled out?