Observational Techniques and Telescopes Flashcards
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Read the first 6 Observational Techniques and Telescopes flashcards as text
What is the James Webb Space Telescope (JWST) primarily designed to observe?
Answer: Infrared wavelengths
JWST is optimized for infrared observations (0.6–28 micrometers), allowing it to see through dust clouds, observe the first galaxies formed after the Big Bang, and characterize exoplanet atmospheres.
What is the radial velocity (Doppler) method of exoplanet detection?
Answer: Detecting the slight wobble in a star's spectrum as an orbiting planet gravitationally tugs the star toward and away from us
The radial velocity method detects exoplanets by measuring periodic Doppler shifts in a star's spectral lines caused by the gravitational pull of an orbiting planet, revealing the planet's minimum mass and orbital period.
What is the advantage of space-based telescopes over ground-based ones?
Answer: Space telescopes avoid atmospheric absorption and blurring, enabling diffraction-limited observations across all wavelengths
Space telescopes operate above Earth's atmosphere, which absorbs UV, X-ray, gamma-ray, and some infrared wavelengths, and causes optical blurring (seeing); space telescopes achieve diffraction-limited performance across the full spectrum.
What is astrometry in modern astronomy?
Answer: The precise measurement of the positions, distances, and motions of celestial objects
Astrometry is the branch of astronomy concerned with precise measurements of positions and motions of celestial objects, foundational for building distance scales, detecting exoplanets via stellar wobble, and mapping the Milky Way.
What is a bolometer used for in astronomy?
Answer: Detecting and measuring the total energy (heat) of incoming radiation, especially at submillimeter and infrared wavelengths
A bolometer measures the power of electromagnetic radiation by absorbing it and measuring the resulting temperature change, widely used in submillimeter and infrared astronomy where photon-counting detectors are less effective.
What is aperture synthesis in radio astronomy?
Answer: Using the Earth's rotation to synthesize a large effective aperture from multiple smaller telescopes
Aperture synthesis exploits Earth's rotation to change the baselines between telescopes over time, effectively synthesizing the aperture of a much larger telescope and enabling high-resolution radio images.