Telescopes

Modern Astronomy

• Began in 1610 with Galileo's telescope.

• Involves various telescope types and applications.

Telescopes

• Telescopes collect photons, focus light, and create images.

• Light Collecting Area: Crucial for observing objects.

• Moving from the human eye to telescopes increases the light-collecting area.

• Larger telescopes combine more photons through lenses and mirrors.

• The transition from Galilean telescopes to later models primarily involved increasing telescope size for enhanced light collection.

Engineering Problems

• Engineering challenges arise when building larger mirrors (over eight meters).

• Maintaining stability while tilting the telescope is crucial.

• Transporting large telescopes to remote locations poses logistical issues.

• Detectors are used to measure photons instead of direct eye observation.

Segmented Mirror Telescopes

• Use multiple smaller segments to create a larger aperture.

• Example: Keck telescope with 36 hexagonal mirrors forming a 10-meter aperture.

• Easier to build and maintain compared to large monolithic mirrors.

• The James Webb Telescope uses segmented mirror principles.

• Computers now assist in mirror adjustments, improving focus.

Space Telescopes

• Avoid atmospheric interference.

  • Atmosphere causes twinkling due to turbulence.

  • Adaptive optics use lasers to correct atmospheric distortion.

• Enable observation at opaque wavelengths (e.g., near-infrared).

• Essential for detecting biosignatures in exoplanet atmospheres.

• Allow continuous observation without day/night limitations.