TYPES OF GALAXIES
the galaxy our sun lives in
MILKY WAY GALAXY
huge, massive spheres of incandescent gas much like our sun
STARS
a large cloud of gas or dust in space
NEBULA
a group of stars forming a recognizable pattern that is traditionally named after its apparent form or identified with a mythological figure
CONSTELLATIONS
super giant, giant, and dwarf
SIZE
look like thin lenses or whirlpools
SPIRAL
biggest star in our solar system
exerts such a strong gravitational pull that no light escapes
BLACKHOLE
reaction in which two or more nuclei are combined to form one or more different atomic nuclei and subatomic particles
NUCLEAR FUSION
brightness of stars
MAGNITUDE
flat, circular or ellipsoidal shapes resembling the central disk of spiral galaxies
ELLIPTICAL
graph showing the relationship between luminosity and temperature
H-R DIAGRAM
the earliest stage of a star's life
PROTOSTAR
distance that light travels in one year which is equal to 9.46 trillion kilometers
LIGHT YEAR
amount of light emitted by an object in a unit of time
LUMINOSITY
lack definite shape or symmetry, large and small magellanic clouds belong to this type
IRREGULAR
star closest to our sun, has a parallax of about 0.76 second
PROXIMA CENTAURI
NEUTRON STAR
a measure of how bright a star appears to be on earth
APPARENT MAGNITUDE
the color of stars depend on differences in this rather than in composition
TEMPERATURE
slightly farther at 180,000 light years away, it is situated at the south celestial pole near the constellation Tucana
SMALL MAGELLANIC CLOUDS
a Greek astronomer, introduced a scheme of classifying stars according to their apparent magnitude
HIPPARCHUS
about 90 percent of the stars in the universe, including the sun, these stars can range from about a tenth of the mass of the sun to up to 200 times as massive.
MAIN SEQUENCE STAR
A change in an object’s direction due to a change in the observer’s position
PARALLAX
a measure of how bright a star would be if all stars were at the same distance
ABSOLUTE MAGNITUDE