Astrofriend's homepage
Share: Twitter Reddit Facebook Gmail Gmail Email
Search Astrofriend's homepage:

Valid CSS!

All pages shall now have been validated

Info Cookies (Kakor) / GDPR


Advertisement /

Space News

Advertisement / Annons:

Debris finder, PolCor-2
An instrument to detect debris around young stars


  1. Introduction
  2. Exoplanets
  3. Stars dust disc
  4. Albanova, research center in Stockholm
  5. The instrument, PolCor-2
  6. The mechanical box's surfaces
  7. Coronagraph
  8. Mirror set one
  9. Filters
  10. Lyot Stop
  11. Servo motors
  12. Polarizer
  13. Parabolic and flat mirror set two
  14. Lucky Imaging
  15. The camera
  16. The computer
  17. Test of the instrument that has been done
  18. Conclusion
  19. End of demonstration
  20. Follow up with links of information about coronagraphs

10: Lyot Stop

We follow the light path ahead and then mover over to the second chamber of the instrument box.

Debris finder or planet hunter

At the top shows the unit that compensates away diffraction from the secondary mirror holder.

In image above, at the top is the optical device that reduces the diffractions spikes. The diffraction spikes we've talked about earlier causing trouble here, just like in the amateur astronomer Newton telescope. The spikes gives disturbing light on the vague light from the dust. It lowers the contrast and something must be done about it. Using a technique called Lyot Stop based on Fourier transform, these spikes is compensated away or at least reduced.

One thing that complicates the matter is that NOT (the telescope normally used) does not have an equatorial mount, it has an azimuthal mount. A good technique for larger telescopes because it simplifies the mechanics but with the disadvantage that the image field rotates. Field of rotation compensates for the telescope itself but spiders (secondary mirror holders) are not. It must be dealt with within this instrument, it is the computer's task to control the servo motor and the rotating filter (Lyot ​​Stop) so it is in the correct position relative the spiders and the spikes it caus. A disadvantage of the Lyot mask is that it screens of some light.

Go Back to content

Go Back
Next part: To page XI

Advertisement / Annons: