ASP Observational Techniques and Telescopes

Question 1

What is the main advantage of a reflecting telescope over a refracting telescope?

Accepted Answer

Reflectors avoid chromatic aberration and can be made larger without distortion

Answer

Reflecting telescopes use mirrors instead of lenses, which eliminates chromatic aberration (color fringing) and allows construction of very large, structurally supported mirrors that could not be achieved with glass lenses.

Question 2

What is the purpose of adaptive optics in ground-based astronomy?

Accepted Answer

To correct for atmospheric distortion in real-time, producing sharper images

Answer

Adaptive optics systems use deformable mirrors controlled by computers to compensate for atmospheric turbulence in real-time, allowing ground-based telescopes to achieve near-diffraction-limited resolution.

Question 3

What is the resolving power of a telescope?

Accepted Answer

The ability to distinguish two closely spaced objects as separate

Answer

Resolving power (or angular resolution) is a telescope's ability to distinguish fine details or two closely spaced objects as separate, determined by aperture size and observing wavelength via the Rayleigh criterion.

Question 4

What is interferometry in radio astronomy?

Accepted Answer

Combining signals from multiple separated telescopes to achieve the resolution of a much larger single dish

Answer

Radio interferometry combines signals from multiple telescopes spread over large baselines to produce angular resolution equivalent to a single telescope the size of the baseline separation, achieving incredible detail.

Question 5

What is the transit method of exoplanet detection?

Accepted Answer

Measuring the dimming of a star's brightness as a planet passes in front of it

Answer

The transit method detects exoplanets by measuring the small, periodic decrease in a star's brightness as an orbiting planet passes between the star and the observer, blocking a fraction of the starlight.

ASP - Astronomical Society of the Pacific Exam Practice Test

ASP - Astronomical Society of the Pacific Exam Practice Test

ASP Observational Techniques and Telescopes