Galaxies, Stars, HR Diagram and Black Holes Flashcards
Rotation Curve
a graph of the orbital velocity of stars at various orbital radii in the galaxy
Dark Halo
unseen matter that lies in the extended halo
Giant Elliptical Galaxy
collision of multiple galaxies– in the center
Active Galactic Nuclei
class of galaxies with extremely bright centers which emit light in radio,x-ray, optical and even gamma rays
What are the three properties of black holes?
mass, spin and charge
Quasars
luminous active galactic nuclei, located in the very distant galaxies
What would happen if you replace our sun with a black hole?
nothing, it would just be dark
disk component
consists of all matter confined to plane of rotation
A globular cluster
smal, spherical clusters of the OLDEST stars
the central bulge
nucleus
the most mysterious region
dark matter
difficult to detect and hard to explain
What are the four types of nubluae
- emission nebulae, 2. planetary nebulae, 3. supernova nebulae, 4. dark nebulae
orion nebula
emission nebula and star formation
molecular cloud
a large cloud full of molecular gas in ammonia and alcohol
stellar clusters
home to emission nebulae
open clusters
few hundred stars and home to the youngest stars
visual binary
one star orbits another
What do binary stars help estimate?
the mass of stars
Spectroscopic binary
indirectly measure the orbits using the doppler shift
eclipsing binary
a dip in the light of one star as the other pass in front and behind
What spectra are the star classified by?
O,B,A,F,G,K,M
Spiral Galaxies
hot, bright, stars- luminous and easy to see
Barred Spiral Galaxies
an elongated nucleus
Flocculant Spiral Galaxy
have a spiral pattern but not a clear set of spiral arms
what are the steps to how a galaxy forms?
- collapse
- globular clusters form
- gas and dust settle in a plane
- stars form in disk
singularity
the point where all the mass is squished together
event horizon
the ‘surface’ of a black hole; matter passing this boundary is trapped forever
radiation core
twin jets of particles and light streaming from the inner edge of the black holes accretion disk
accretion disk
a flat, spinning donut of hot gas swirling around and into a black hole
