Download Stars - Quia

What is a star?
- body of gasses that give off “tons of”
energy (light & heat)
- clusters = those little specks in the sky
that we see may really be more than
one star….
PHYSICAL PROPERTIES
OF STARS -1. Differ in
SIZE
2. Differ in COLOR
3. Differ in D I S T A N C E from us
4. Differ in COMPOSITION
5. Differ in BRIGHTNESS
Our Sun in considered
an average-sized star!
 The diameter of our sun is about 109
times the diameter of the Earth!
X 109 =
 It has been burning for about 5 billion
years. It is only middle-aged. It will burn
for about 5 billion more years!!
How Are Star Sizes Like
Celebrities?
• Sometimes the larger the star,
the shorter the life span.
• This is like the bigger the
celebrity (more famous), the
shorter their life span!
Ex. James Dean, Chris Farley
BRIGHTNESS
Function of how LARGE
the star is, how OLD it is,
and how FAR AWAY.
APPARENT MAGNITUDE -
IS HOW BRIGHT
THE STAR IS TO
OBSERVERS
ON EARTH
APPARENT Magnitude:
- the
brightness how WE see it
- the brightest star in a
constellation is called the ‘alpha’,
then ‘beta’, etc…
Size and closeness can effect
apparent magnitude
-
Distance
to Stars
Our Sun is the closest star at 93
million miles distance. Next is Alpha
Centauri at a distance of 4.27 light
years. A light year is 5.88 trillion miles.
Stellar Parallax
Parallax = shift in angle that occurs
when a nearby object is seen against a
distant backdrop from two different
perspectives
is a star’s apparent brightness if
we could position the star 32.6
light-years away (the distance
that is the furthest star we can
see from Earth)
THERE ARE
DIFFERENT WAYS TO
MEASURE STAR
BRIGHTNESS :
SIZE
-depends on
and TEMPERATURE
COLOR
Yes, stars have different
colors!
The temperature of the star
determines its color.
Star Color
- if you look close enough…you’ll see
colors….
- blue
= HOT = 17,000o
- red = not so hot = 1,700o
Our sun = orange
~ 10,000o
What are the Star Colors?
Blue
White
Yellow
Orange
Red
Hottest
Coolest
Star patterns :
- 1000’s of years of observations - want
to organize what they saw
-constellations = they are named after
animals, greek gods and legendary
heroes
- there are 88 named constellations
What should be the brightest star
for us?
- THE SUN!
- it’s
the closest - so it should appear
the brightest
- BUT - it’s just average in reality
- ABSOLUTE magnitude = real
brightness
-
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A. 70% HYDROGEN
B. 28 % HELIUM
C. 1-2% heavy elements
like IRON, TITANIUM,
CALCIUM & SODIUM
D. 2 % other heavy
elements
•Every element has its
own characteristic
color when made to
emit light.
•The light from
glowing elements can
be analyzed with a
Spectroscope
Spectrum
Viewed from these two different locations,
a nearby star would appear to shift position
with respect to more distant stars
The bigger the shift, the closer the start is to earth