Astronomy 100-09 Exam 1 Fall 2022 Flashcards
What is the definition of science?
the process by which the physical universe is studied, and understood
What are the physical laws in order?
data, model, theory
What is equal to a kilo?
10^3 or 1,000
What is equal to mega?
10^6 or 1,000,000
What is equal to giga?
10^9 or 1,000,000,000
What is equal to centi?
10^-2 or 0.02
What is equal to micro?
10^-6 or 0.000001
What is an astronomical unit and what is the constant?
average distance between earth and sun, 1.496x10^8 km
What is a light year and what is the constant?
the distance that light travels in one year, 9.46x10^12, or 12 trillion miles
What is a parsec and what is the constant?
distance and which 1 AU subtends an angel of 1 second of arc ( 1”), 1 pc averages to 3.25 ly or 3.09x10^13 km
What is the definition of angular diameter?
how big an object looks, expressed as an angle
What is 1 degree equal in arcminutes?
60 arcminutes or 60’
What is 1 arcminute or 1’ equal to in arcseconds?
60 arcseconds or 60”
What is 1 degree equal in arcseconds?
3600” or 3600 arcseconds
what is the celestial sphere?
the sky that appears to our eyes as a large dome at the center, excludes sun, moon, and planets
What is diurnal motion?
apparent daily motion of all celestial objects from east to west. caused by earths rotation from west to east, includes rising and setting phenomena
What is annual motion?
apparent motion of the sun WRT the “ fixed” stars, over the course of a year. caused by earths revolution of the sun, gives rise to seasonal constellations
Does earth orbit clockwise or counter-clock wise?
counter-clock wise
Earth’s rotational axis is tilted by?
23.5%
What is the vernal equinox?
the intersection of the CELESTIAL EQUATOR
and the ECLIPTIC, at the ascending node (south to north); Sun
appears directly over Earth’s equator.
What is the Summer Solstice?
the maximum northern position of the Sun in
the sky; Sun stops moving south to north, continues moving
west to east, in its apparent annual motion. 23.5 degrees north the celestial equator
What is Autumnal Equinox?
the intersection of the CELESTIAL EQUATOR
and the ECLIPTIC, at the descending node (north to south); Sun
appears directly over Earth’s equator.