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Unformatted text preview: warf to about a million times that of the sun for
the hottest known super-giant star. Astronomers assign stars
magnitudes based on how bright they are. Apparent magnitude
measures how bright a star appears to be from Earth. Absolute
magnitude measures its true luminosity.
The brighter the star, the lower its
luminosity. Every 5 magnitudes
corresponds to brightness changing
by a factor of 100. For example, a
magnitude 1 star is 10,000 times
brighter than a magnitude 11 star.
Besides the sun, the brightest star as
seen from Earth is Sirius with an
apparent magnitude of -1.6. Light Transmission
Transparent: Materials, such as window glass,
through which light can travel easily and through
which other objects can clearly be seen.
Translucent: Materials, such as glass blocks,
through which light can pass through but no clear
image can be seen.
Opaque: Materials which absorb and reflect light.
Objects cannot be seen through the material. Most
objects are opaque. Thin Films & Thin Film Interfe...
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This note was uploaded on 11/17/2011 for the course PHYS 121 taught by Professor Burgeson during the Fall '11 term at BYU.
- Fall '11