Pre-Lab Quiz:аObserving Obscuria


Discuss each question with your team. Be prepared to explain the reasoning behind your team's answers after the quiz.

1. When looking at objects in the night sky, which direction has the least amount of interference from the atmosphere/light pollution?
а а а - Toward the Horizon, facing South
а а а -аToward the Horizon, facing North
а а а -аIt depends where you are on Earth
а а а -аStraight up toward the zenith

2. When will a given object be at its greatest altitude in the sky relative to wherever you are observing it?
а а а -аWhen it reaches the zenith
а а а -аWhen it crosses the local meridian
а а а -аWhen its right ascension is at 12 hours
а а а -аAt midnight

3. How is local sidereal time defined?
а а а -аIt is equal to the sun's right ascension on the ecliptic.
а а а - It is the difference between the Earth's prime meridian and the celestial sphere prime meridian.
а а а -аIt is equal to the right ascension of stars that are currently crossing the local meridian.
а а а -аIt is equal to the right ascension of stars that are just rising.

4. Why don’t planets, asteroids, and comets have the same RA and Dec all year?

5. Give the electromagnetic spectrum in order of smallest to largest wavelength.

6. The images below were both taken with the Rigel telescope. If the target objects in the center of each image are both the same apparent magnitude, for which would you want to use a longer exposure time?
а а а -аThe left-hand image
а а а -аThe right-hand image
а а а -аboth, to get as much light as possible
а а а -аneither, the exposure time is irrelevant

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