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First Direct Photo of Exoplanet Confirmed
An anonymous reader noted a report confirming the first ever exoplanet actually photographed from telescopes on earth. Every other exoplanet so far 'observed' has been done by measuring wobbles of stars pulled by planetary gravity. But this one is a photograph. And that's just plain cool.
I see this as a big triumph of adaptic optics. This picture was not made by a space telescope, but by an earth-based one!
Indeed, hope the liquid mirror option becomes practical and viable so we can achieve more amazing photographs and data like this. Although I have to wonder why they didn't use an orbiting satellite like Hubble to avoid Earth's atmosphere when photographing such an amazing thing. Have terrestrial adaptive optic solutions already caught up with orbiting satellites?
My work here is dung.
Is there some weird definition of "Alien" that I dont know of?
Usually it means extra-terrestrial, but in this case they mean extra-solar (a word also used in the article). I'll assume the guy who came up with the headline is not the guy who wrote the article.
There are several direct images of exoplanets available. Hubble took one of a planet around Fomalhaut, which was announced the same day that Keck announced three planets around HR 8799 (Nov 13, 2008). The next week, ESO announced a possible planet around Beta Pictoris, which has recently been confirmed. What these folks at Gemini are saying is that they announced a possible direct image earlier in 2008, which they have now confirmed, so theirs was really the first. It is a game of "who got the first direct image of a planet around another star?". It doesn't really matter, but it is very cool that we can now directly see not only the 8 planets in our solar system, but also at least 6 more in other solar systems. At some pivotal point in the near future we will have more pictures of planets outside our solar system than within it!
OK - Here's the math ...
100 light-years = 1 quadrillion kilometers -- You want a 1 meter resolution at that distance, so you need an angular resolution alpha, where tan(alpha) = 1 / 10^18 --> alpha = 5.7 x 10^-17 degrees
Let's use Hubble as a scaling proxy. It has a 2.5 meter mirror and 1/20th of an arc second resolution. Converting units, that resolution is 1 / (20*60*60) = 1.4 x 10^-5 degrees. Now, simply scale to get the desired resolution and you have the diameter of the mirror = 2.5 * 1.4 x 10^-5 / 5.7 x 10^-17
The diameter you want is 614 million kilometers, or more than 4 times the distance between Earth and the Sun. Good luck building that.