The EMS (electromagnetic spectrum)
what is the EM Spectrum?
The electromagnetic (EM) spectrum is the range of all types of EM radiation.
what is a nebula
Giant clouds of gas and dust and as the nebula collapses, gravity increases and the cloud begins to spin
what is the inner core?
The inner core is plasma with a very hot temperature.
how are spiral galaxies characterized?
their characterized the compactness of their spiral arms
how large do astronomers guess the galaxy was before the big bang?
no bigger than the period at the end of this sentence.
what is radiation
Radiation is energy that travels and spreads out as it goes
what is a main-sequence star?
These stars will be hotter and have a shorter life span
what is the radiative zone?
The energy released in the core travels extremely slowly through this zone.
how are elliptical galaxies characterized?
their characterized the ellipticity of the galaxy
what way are all galaxies moving?
away from one another
what is the frequency of a wave
The frequency (v) of a wave is the number of waves to cross a point in 1 second
what is a red giant?
When the light elements are used up, the star can no longer resist gravity and begins to collapse inward. The outer layers of the sun grow outward and cool down
what is the convection zone?
Hot material from near the radiative zone rises, cools at the sun’s surface, and then plunges back downward to the radiative zone.
what two subgroups are spiral galaxies divided into?
normal spirals and barred spirals
what does Hubble's law state?
the farther away a galaxy is from us the faster away it is moving
the wavelength is the distance from crest to crest on a wave
what is the main sequence comprised of?
Stars in the stable phase of hydrogen burning lie along the Main Sequence according to their mass.
what is the photosphere?
The visible “surface” of the sun, the region that emits sunlight.
what are irregular galaxies?
irregular galaxies have odd shapes
how long is it expected for the universe to keep expanding?
forever
list the types of radiation in order from least to greatest.
Radio Waves
Microwaves
Infrared
Visible Light
Ultra Violet
X-Rays
Gamma Rays
what is the HR diagram used for?
used to classify stars according to their luminosity, spectral type, color, temperature, and evolutionary stage.
what is the corona?
It is the sun’s halo
what format is the Hubble classification system put in?
The Hubble tuning fork
what evidence is there of the big bang?
left over radiation