AST201H1 Chapter 6: CHAPTER 6 ASTRO.docx

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Michael Reid

Document Summary

Refraction is the bending of a wave. Nowadays, most images are recorded digitally with electronic detectors called charge coupled devices (ccds). A ccd is a chip of silicon is chip that is extremely sensitive to photons. Its physically divided into a grid of squares called picture elements (pixels) 2 most important properties of a telescope: light collecting area and angular resolution. A 10m telescope has a light collecting area 25 times greater than a 2m telescope ([10/2]^2 = 25) Angular resolution is the smallest angle over which we can tell two dots or two stars are distinct (human angular resolution is 1/60 degrees) Hubble space telescope (2. 4m) has a angular resolution of about 0. 05 arcsecond for visible light. The angular resolution that a telescope could achieve if it were limited only by the interference of light waves is also called diffraction limit (depends on diameter of telescope and wavelength of light)