PHYS117 General Astronomy Lecture: Telescopes

Flashcards covering key vocabulary related to general astronomy and telescopes, including types of telescopes, their principles, and common problems.

Aperture

The size of the open collecting end of a telescope.

Telescopes

Act like funnels for light, concentrating input into a focal point.

Focal Point

The point where light is concentrated in a telescope.

Refraction

A method of creating a funnel effect in telescopes by bending light.

Refracting Telescope

A telescope that uses carefully made lenses to bend light.

Reflection

A method of creating a funnel effect in telescopes by bouncing light.

Reflecting Telescope

A telescope that uses carefully made mirrors to bend light.

Chromatic Aberration

A problem with refracting telescopes where different colors of light are not focused at the same point, leading to unclear pictures.

Spherical Aberration

A problem with reflecting telescopes due to the mirror's shape (spherical vs. parabolic), causing light to not focus at a single point.

Atmospheric Absorption

Earth's atmosphere absorbs some colors completely, making certain light unobservable from the surface.

Space Telescopes

Telescopes placed in space (e.g., Hubble ST, James Webb ST) to observe light that is absorbed by Earth's atmosphere.

Atmospheric Motion

The movement of Earth's air which causes 'twinkling' and smears out data observed by ground-based telescopes.

Adaptive Optics

A solution to atmospheric distortion that uses a laser to project a 'guide star' and computers to correct for the air's motion.

Guide Star

A laser-projected point used by adaptive optics systems to measure and correct for atmospheric distortion.