1. Reading the Celestial sphere
Mr. Thompson

2. THINK About the city you were born in?
HOW WOULD YOU TELL SOMEONE WHERE THIS CITY IS LOCATED IF YOU WERE IN JAPAN?
THINK About the city you were born in?

3. On Earth, we locate places three different ways:
1. CITY, STATE, COUNTRY, CONTINENT
2. LOCAL COORDINATE SYSTEM
Example: House numbers to locate a house on a street
3. GLOBAL COORDINATE SYSTEM
Latitude and Longitude
On Earth, we locate places three different ways:

4. Global coordinate system: Longitude and latitude

5. LINES OF LATITUDE Horizontal mapping of the Earth
Runs parallel to the Equator
Measures how far north or south of the equator a place is located.
The equator is the starting point for measuring latitude (0°)
The number of latitude degrees will be larger the further away from the equator the place is located, all the way up to 90° at the poles.
Locations are referred to as ______ degrees North/ South.

6. LINES OF LONGITUDE Vertical mapping of the Earth, called Meridians.
Vertical lines run around the Earth.
Measures how far east or west of the Prime Meridian a place is located.
The Prime Meridian (Greenwich, England) is the starting point for measuring longitude (0°)
To measure longitude east or west of the Prime Meridian, there are 180 vertical longitude lines east of the Prime Meridian and 180 vertical longitude lines west of the Prime Meridian. The International Date Line is located at 180° line.
Locations are referred to as ______ degrees East/ West.

7. Object lesson

8. L O N G I T U D E L A T I U D E
On Earth, What does the tomato represent? What does the orange represent?

9. Dome of the sky

10. DEFINTIONS ZENITH – THE POINT DIRECTLY ABOVE THE OBSERVER.
HORIZON – ALL THESE POINTS THAT LIE 90° DOWN FROM THE ZENITH.
NADIR – THE POINT DIRECTLY BELOW THE OBSERVER.
MERIDIAN – A VERTICAL CIRCLE DEFINED BY THE PATH THAT STARTS AT THE ZENITH AND CROSSES THE HORIZON AT A POINT DIRECTLY NORTH.
DEFINTIONS

11. In the sky, we locate places also in three different ways:
1. GEOGRAPHIC
Star (or Object), Constellation
2. LOCAL COORDINATE SYSTEM
Altitude and Azimuth
3. GLOBAL COORDINATE SYSTEM
Right Ascension and Declination
In the sky, we locate places also in three different ways:

12. geographic: Star (or OBJECT),constellation
Polaris, Ursa Minor
Examples:
Sirius, Canis Major
geographic: Star (or OBJECT),constellation

13. The ALTITUDE is the distance an object appears to be above the horizon
The ALTITUDE is the distance an object appears to be above the horizon. The angle is measured up from the closest point on the horizon.
The AZIMUTH of an object is the angular distance along the horizon to the location of the object. By convention, azimuth
is measured from north towards the east along the horizon.
Altitude and azimuth

14. RIGHT ASCENTION AND DECLINATION
A GRID WHICH IS FIXED TO THE BACKGROUND STARS
SIMILAR TO LATITUDE AND LONGITUDE ON EARTH
Video Clip
RIGHT ASCENTION AND DECLINATION

15. declination DECLINATION The celestial equivalent to latitude.
DEC locates where a star is north or south of the celestial equator.
The celestial equator is the starting point at 0°.
North and south of the celestial equator, declination is marked with a “plus” and “minus” sign.
Additionally, each degree is split into 60 smaller units called “minutes of arc”, marked by a ‘, and each minute is split into 60 “seconds of arc”, marked by a “.
declination

16. Right ascension RIGHT ASCENSION The celestial equivalent to longitude.
RA locates where a star is on the celestial equator.
Measured not in degrees but in “hours”, from 0h to 24h.  Astronomers developed this measurement because the celestial sphere appears to turn once every 24 hours.  
With 24 hours in the full 360 degrees of sky, each hour corresponds to 15 degrees of angular distance and is split into 60 minutes and each minute into 60 seconds.
The First Point of Aries, which is actually in Pisces, defines the zero-point.
Right ascension

17. The first point of aries
One of the two points on the Celestial Sphere where the Ecliptic and the Celestial Equator cross one another.
Not a fixed point in space.
Moves 1° every 70 years along the Ecliptic.
Originally in the constellation Aries, moved into Pisces in 70 B.C., will move into Aquarius in year 2600.
Will return to Aries in approx. 23,000 years.
The first point of aries

19. Example of right ascension and declination
SIRIUS
RA = 06h 45m
DEC = -16.7°
Example of right ascension and declination

20. R A
I S
G C
H E
T N S I O N D E C L I N A T O
On the celestial sphere, What does the tomato represent? What does the orange represent?

21. The Right Ascension and Declination of each star are fixed from day to day and year to year.  But because the Earth is wobbling in space because of the gravitational influence of the Moon and Sun, the coordinates of celestial objects change over the course of decades.  Every 50 years or so, star maps and star coordinates are updated.  Current star maps are accurate as of the year
Good to know

22. REVIEW QUESTIONS

23. LABEL THE HORIZON, MERIDIAN AND ZENITH IN THE DIAGRAMC B
REVIEW QUESTION #1

24. LABEL THE HORIZON, MERIDIAN AND ZENITH IN THE DIAGRAM
A. ZENITH
C. MERIDIAN
B. HORIZON
REVIEW QUESTION #1

25. WHICH ONE REPRESENTS AZIMUTH?B
WHICH ONE REPRESENTS AZIMUTH?
REVIEW QUESTION #2

26. WHICH ONE REPRESENTS AZIMUTH?B
WHICH ONE REPRESENTS AZIMUTH?
REVIEW QUESTION #2

27. WHAT IS IT? REVIEW QUESTION #3
This celestial measurement deals with where stars are on the celestial equator.
It’s measured in “hours”.
It’s similar to longitude on Earth.
WHAT IS IT?
REVIEW QUESTION #3

28. RIGHT ASCENSION WHAT IS IT? REVIEW QUESTION #3
This celestial measurement deals with where stars are on the celestial equator.
It’s measured in “hours”.
It’s similar to longitude on Earth.
WHAT IS IT?
RIGHT ASCENSION
REVIEW QUESTION #3