Lecture 12: Searching for planets orbiting other stars. I. Light & Telescopes • Direct detection of planets around other stars. • Light and telescopes - optics. • Challenges and promises of direct detection.
Dec 22, 2015
Lecture 12: Searching for planets orbiting other stars. I. Light & Telescopes
• Direct detection of planets around other stars.• Light and telescopes - optics.• Challenges and promises of direct detection.
Direct Detection of Planets
• Direct detection is challenging because of the technicallimits oftelescopicobservations
The nature of light
• Light - electromagnetic waves that have:
Wavelength
Frequency
Speed
… and
Energy
Direct Detection of Planets
• Direct detection is challenging because of the technicallimits oftelescopicobservations
Direct Detection of Planets• The best case to-date of a planet-like system detected ininfrared light:
Light and Telescopes - Optics
•Resolution - theultimate limitationcomes from thewave properties oflight:
Light and Telescopes - Optics
• Resolution - theultimate limitationcomes from thewave properties oflight:
Light and Telescopes
• The challenge ofdetecting planets:
Spectrum of the Sun,and as it is reflected by3 of the planets:
Telescopes
• The largest today -the Keck telescopesare composite mirrorreflectors (D~ 10m):
They also form a pair -an interferometer.
Telescopes
• Harvard is a partnerin the constructionof the largest newtelescope:
The Giant Magellan Telescope (D ~ 25 m)
Main points to take home:
1) Visible light: form of electromagnetic energy (radiation) to which our eyes are sensitive.
2) Energy & power vs. color3) Four basic ways light and matter interact.4) Telescopes: optics & 2 types of design.5) Angular Resolution vs. light gathering