stars and astrology Flashcards
hr measured by
x =temp
y= lumosity
hr diagram
hertz Russell
green band on hr
main sequence
90% of stars life
found top left to lower right
dust cloud or nebula
the start of star=beginning of life
mostly hydrogen and 7% helium
a kid -star stage
protostar
around a million years after nebula
gravity and temp increase the start of the fusing
true star “teen- young adult”
core reaches 15mill degrees Celciu
“start of fusion”
-hydrogen turns to helium
adult - main part of stars life
main sequence
90% of life
outward heat pressure balanced by gravity
fuse can last for mills or bills
hotter stars are
cooler stars are
hotter blue -short wave lengths
cooler red orange- longer wave lengths like our sun
bigger stars
shorter stars
why?
bigger - shorter stars (millons of yrs)
smaller - longer lives (billions of yrs”
the forming of a red giant - explain process
once star runs out of elements to fuse to the core begins to contract and gravity loosens-
so outer later expands to 1000x bigger than main sequence
stable red giant
once stable outer layer gives off cooler longer wave lengths (red)
other elements in
fuses other elements up to iron
becuase if helium core gets hot enough the nuclei will form new elements
life after red giant
after iron no fuse
used up fuel
shrinks to white dwarf-dense n glows
massive stars (blue)
5-20x mass of sun
very bright cause it’s big
red super giant
massive star gets bigger
will end in super nova
life after a super nova (massive red super giant explosion)
neutron star - super small super dense and spins extremely fast
or black hole
geocentric model
model where sun revolves around earth
heliocentric
earth around sun
asterism
stars part of a bigger constellations
right ascension
⬅️➡️ longitude
declination
⬆️⬇️latitude
why do we only certain stars on certain seasons
we only see stars opposite of the sun because of how bright the sun is
when earth isn’t faced towards the sun it’s dark(night) and when it is the sun blocks out the sky(day)
which star will be our next North Star
why
vega will be new North Star
because the tilt of the earth is determined by a wobble
what’s the name of this wobble
precision -the wobble of the axis that cause this In the night sky to change Position to us
takes 26,000yrs
1 degree equals
“1 hour” 60secs
1’ equals
60seconds
1” equals
1second -3600” seconds in 1 degree(hour)
sun low point
sun hight point
low - winter
high - summer
planets follow a what path?
why
ecliptic path
becuase they are all on the same plain revolving around the sun
eccentricity explain it
how ecliptic all the orbit of a planet is
0 = circle
1 = almost a line
as time goes on the eccentricity of a planet will be greater
precession
the wobbling motion of a planet and changes the tilt of axis
and chances seasons
every 26,000 years
keplers 1st law
all planets orbit the sun in a path that resembles a ellipse
sun located at center
keplers 2nd law
2 imaginary lines drawn from center of sub to planet - think of sweeping model
EQUAL ARES IN EQUAL TIMES
3rd kepler law
ratio of the squared periods of any 2 planets is equal to the ratio of the cubes of their average distance to the sun
p2= a3
3rd law
p = years
a= au
parallax
a way to find distance from star
if the object is closer the angle is larger
if object is further the angle gets smalle
magnitude
brightness of star on a scale were
neg = bright (-26 is sun)
positive = dim (7)
apparent magnitude
the brightness how it appears
absolute magnitude
putting stars side by side at 3.62LY away to compare against each other
Milky Way
spiral galaxy
3millon LY across in diameter
andromeda galaxy
also spiral
closest LARGE galaxy
2.5 millon ly away
Magellanic Cloud
closet galaxy to ours
a irregular galaxy
200,000 LY across smaller then ours
spirals
most galaxies are spirals
older stars in center
younger within spiraling arms
elliptical
takes a spherical shape like a globe
far less gas and dust then spirals
few new stars form in these
irregular
No simple shape
lots of dust and gas
young stars
km = to miles miles = to km
- 61miles
0. 621 km
1 mile = feet
5280ft
