Spectroscopy + Telescopes

spectroscopy

the study of the properties of light and the way it interacts with matter

Who used the prism to split light into the spectrum and said that light is a mixture of different light?

Isaac Newton

Who proposed light travels in the form of waves?

Christian Huygens

spectroscope

an instrument which consists of a slit and a grating/prism, which produces a spectrum for visual observation

Electromagnetic spectrum

in the form of electromagnetic waves that transfer energy as they travel through space. These waves travel at the speed of light

(186,000 miles/sec)(300,000 km/sec)

Optical telescope

used to observe wavelengths in the infrared and visible

SOFIA

Stratospheric Observatory for Infrared Astronomy

Emission spectrum

spectrum containing bright lines produced by an element. Each element has its own unique emission spectrum

Absorption spectrum

continuous spectrum interrupted by lines or has certain wavelengths missing or reduced

Peak wavelength

wavelength of light with the most energy emitted by an object

Redshift

moving away from us

Who aligned 2 lenses of different curvatures and focal lengths (a refractor)?

Hans Lippershey

Who was the first to document his findings with the telescope and grind his own lenses?

Galileo

Who discovered 4 of Jupiter’s moons, crater walls on moon, Venus’ phases, sunspots, and Saturn’s rings

Galileo

Who worked on a telescope to get rid of chromatic aberration?

Isaac Newton

Who made telescopes, discovered Uranus. and discovered infrared?

William Herschel

Refraction

bending of light when it passes from one substance into another

Reflection

light changes direction using a mirror.

Two most important properties of a telescope

light-collecting area and angular resolution

Light-collecting area

↑ collecting area, ↑ light gathered in a short amount of time

Angular resolution

↑ diameter, ↑ greater detail

What allows for easier repair and stability?

Segmented mirrors

Primary telescope parameters

Focal length, focal plane, focal ratio, aperture diameter

Focal length

distance from the primary objective mirror/lens to the focal plane of the telescope

Focal plane

location where the light from a telescope comes to a focus

Focal ratio

light gathering ability and the speed of the telescope

(f-stops)(focal length / aperture)

Aperture diameter

diameter of the main lens or mirror

Types of reflectors

Cassegrain and Newtonian

What are telescopes used for?

imaging, spectroscopy, photometry, astrometry

Photometry

a technique that measures the brightness of a star in an image

Each pixel on a CCD will have had a certain # of photons fall on it during an exposure

Astrometry

deals with measurements, positions, and movements of celestial bodies

What affects ground-based observation?

turbulence, weather, humidity, and light pollution

Adaptive optics

cancel out the shimmer