Transcript File

Star Charts
and Coordinate Systems
Astronomy Picture of the Day
A Star Cluster in the Rosette Nebula
Astronomy Picture of the Day
This striking pair of galaxies is far, far away ...
about 350 million light-years from Earth.
Astronomy Picture of the Day
The Constellation Orion
The changing stars
• The stars we see change with time
of night and season of year - why?
• The sky is a sphere with Earth at
the center.
• Observer can see only sky above
the horizon
• horizon……..an imaginary plane
tangent to Earth at the observer
Earth and Sky Terms
• Latitude….LINES PARALLEL TO
THE EQUATOR
• Longitude……LINES THAT RUN
FROM POLE TO POLE
• Prime Meridian…RUNS FROM
POLE TO POLE THROUGH…....
• ……….Greenwich England
Celestial sphere Terms
• North Celestial Pole….same as
North pole
• South Celestial Pole….same as
South pole
• Celestial
Equator……….Projection of
earth’s equator out to the sky
• altitude - the angle of a star above the
horizon
• The North Star, Polaris, is not the brightest
star in the sky but remains in a fixed
position in the sky.
• The angle of Polaris above your horizon is
the same as your latitude in degrees.
Right Ascension
R.A.
• Distance measured eastward
along the celestial equator from
zero point, called the vernal
equinox
• measured in hours and minutes
……. 15hr 10 min, 23 hr, 5 min
Declination
Dec
• Angular distance above or
below the celestial equator
o
• measured in degrees…. 0 ,
15o, 30o
Create own
Celestial
Sphere
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Star Chart
• The North Star
• The Big Dipper
• The Little Dipper
• Cassiopeia.
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Star Chart
Little dipper
Cepheus
Draco
Orion
Gemini
Find the coordinates of Betelgeuse.
Earth and Sky Terms
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Right Ascension
Declination
Ecliptic
Vernal Equinox
Autumnal Equinox
Summer Solstice
Winter Solstice