Astronomy Review Flashcards
What main factor is used to classify galaxies (regardless of the system)?
a) size
b) closeness to Earth
c) shape
d) the Hubble constant
c) shape
Stars that are 8 times more massive that the Sun are most likely to end up as what kind of stars?
a) red giants
b) white dwarfs
c) neutron stars
d) black holes
c) neutron star
An Sa galaxy is best described as:
a) spiral with a large bright nucleus and tightly wound arms
b) spiral with well defined arms and a small nucleus
c) spiral with not well defined arms
d) spiral with a straight line through the centre called a bar
a) spiral with a large bright nucleus and tightly wound arms
A star that demonstrates a red shift then a blue shift is:
a) likely orbiting the sun
b) demonstrating a wobble effect from an associated planet
c) in a binary star system
d) all of the above
e) b or c is possible
e) can be caused by an associated planet or a binary star system
List 3 pieces of evidence for the Big Bang Theory (not the TV show!).
1) Galaxies are moving away from us
2) Cosmic background radiation
3) Quasars
NOTE: these are not the only answers, and you should be able to describe the reason that each supports the Big Bang Theory
What type of spectrum does a star produce?
Absorption spectrum
What type of spectrum does a nebula produce?
Emission spectrum
List the following measurements from largest to smallest: ly, AU, km, pc
largest: pc, ly, AU, km (smallest)
What is the difference between a comet and a meteor?
Meteor has entered our atmosphere and is producing light because of friction with air particles. Comets produce light because of their interaction with the sun. Comets have larger, fanned out tails than meteors and last much longer. Comets are usually found in large, exaggerated elliptical orbits around the sun whereas meteors are pieces of rock and dust usually from the asteroid belt.
Why are black holes “black”?
No light escapes
What evidence supported the idea that a black hole was at the centre of our galaxy?
1) immense gravitational force in the centre
2) stars near the centre have very elongated elliptical orbits
What is one characteristic of the stars in the instability strip of the HR diagram?
Pulsate
What kind of electromagnetic emissions can sometimes be “seen” from a black hole?
x-rays
What are 3 characteristics of population I stars?
1) contain some heavy elements
2) are younger than population II stars
3) generally found in the disk (particularly the spirals if present)
Copernicus proposed the ___________ model of the solar system.
Heliocentric
