A German physicist
February 22, 1857 – January 1,
Was the first to satisfactorily
demonstrate the existence of
electromagnetic waves by
building an apparatus to
produce and detect VHF or
UHF radio waves.
He improved on James
Maxwell’s work which
demonstrated that electricity,
magnetism and even light are
all manifestations of the same
Schematic view of a pulsar. The sphere in
the middle represents the neutron star,
the curves indicate the magnetic field
lines and the protruding cones represent
the emission beams.
Generated by Earth’s
iron-nickel core and
molten outer core.
Protects us from
Occurs near the
North and South
Charged particles hit
the atmosphere near
the magnetic poles.
emitted from the surface of
an object which is due to the
Generated when heat from
the movement of charged
particles within atoms is
2. Surface Area
each part of the
spectrum to collect
Filament system around NGC 1275
Every object in the Universe,
including people, emit radiation at
all times, because charged
particles in them are in constant
No natural object emits all its
radiation at just one frequency.
The total amount of emitted
energy goes up with the
Studying how the intensity of the
object’s radiation is distrusted
across the EM spectrum, we can
learn a lot about an object’s
Blackbody curves describe the
distribution of the emitted
Cool dark objects may emit only radio
waves around 60K.
Young stars have higher temps. Around
600K, which emit radiation in the IR part
of the spectrum.
Mature stars, like our Sun, emit radiation
around 6000K, which is the brightest
region of the visible spectrum.
Some very bright, hot stars, such as these
in a cluster called Messier 2 emit
radiation at 60,000K and radiate strongly
along the ultraviolet part of the