European Extremely Large Telescope given go-ahead
bbc.co.uk
bbc.co.uk
This is unprecedented, right? I have been wondering for a while if such a thing is or will be possible. I assumed the distances were simply too great.
I see now that it is possible to directly image gas giants, but not to my knowledge small rocky planets.
Best wayto image rocky planets is in the mid-IR where they are brighter and their parent star is less bright.
Mid-IR detectors weren't very good 30years ago when todays large telescopes were planed and the mid IR telescopes that have been built were based around poor detectors from 30years earlier and so are small.
Of course what you claim a telescope is for and what is the fashionable topic once it's running can be different. That's the nice thing about telescopes compared to say an LHC - decades after they open they are finding new unusual things with new instruments.
In this particular application it would be more difficult since you not only have to detect the source on its own, you have to block out the glare from the parent star. Usually the main problem in this sort of work is making sure that the source you are detecting is actually a real thing and is not just an artifact from the way you block out the light from the parent star.
A 0mag star gives you about 1000photons/s/cm^2/Angstrom so the 40m telescope in visible light would capture about 2E13 photons/s for the brightest star in the sky.
But 32mag is 2.51^32 = 6E12 times fainter so only a few 1000 photons in an hour long exposure.