Direct Imaging of Exoplanets with Adaptive Optics, Coronagraphy, and Differential Imaging

Not a povray animation, but it shows the interesting aspects of trying to image an extrasolar planet from the ground:

Atmospheric turbulence is corrected by so-called adaptive optics on modern telescopes. The animation shows a "normal" observation on the left, seeing correctd by standard, contemporary AO systems in the center, and a correction as it is expected from the next generation of "extreme" AO systems.

The top row shows the instantaneous image an astronomer would get to see through an eye-piece, in the bottom row a long-exposure image is integrated up to 10s.

Embedded are a number of planets, in directions from the primary and at contrast ratios denoted by the yellow cross in the middle.

After the image integration is finished, we can see how the actual contrast improved in the three cases first when a standard classical Lyot coronagraph is introduced, and then what happens when also "differential imaging" is pallied. In this particular case, I show spectral differential imaging (SDI), where images are taken at slightly different wavelengths, on at which the planets are bright, and one at which the planets are faint.

Category:

Science & Technology

Tags:

• Astronomy
• Astrophysics
• Adaptive Optics
• Exoplanets