1. Open up your laptops, go to MrHyatt.rocks, and do today’s bellwork
Scale
Scale Description 4
Through independent work beyond what was taught in class, you could:
investigate the location of seasonal constellations in the local sky.
predict location of constellations at future times.
determine the celestial equator, latitude and position of the Pole Star for a given position on the Earth.
determine the distances of stars in a given constellation to each other and to Earth. 3
You will be able to:
describe and apply the coordinate system used to locate objects in the sky.
distinguish the various methods of measuring astronomical distances and apply each in appropriate situations. 2
determine the meaning of symbols, key terms, and other astronomy specific words and phrases as they are used in context to relevant topics
label diagrams with degree measurements
describe how or why different units of measurement are needed for distances in space 1
You will be able to
list the different units of measurement needed to measure distances in space
Progress Report Grades are due today, so….
Any late work that is still missing or late will be a 0 for the progress report.

3. 40ᵒ x 300ᵒ

4. Horizon System Review Look For: Horizon: 0 degrees Zenith: Straight Up
Meridian: Line over your head
Stars moving over time
Altitude: 0-90 degrees
Azimuth: degrees

8. Where does it start? (Where is Zero)
On Planet Earth
In Space (On Celestial Sphere)
Latitude:
Equator
Longitude:
Prime Meridian
Declination:
Celestial Equator
Right Ascension
Vernal Equinox

9. Very similar to latitude
Measured in degrees
Very similar to latitude
Instead of South, it uses negative
32ᵒS = ᵒ

10. Declination up and down (similar to altitude, but fixed)
Since ancient Babylonia, people have divided both degrees and hours into finer units by means of base-60 arithmetic.
In 1° there are 60 arcminutes, written 60'. One arcminute contains 60 arcseconds, written 60".
A good telescope in good sky conditions can resolve details about as fine as 1" on the surface of the celestial sphere. By comparison, 1" of latitude on Earth is about 101 feet. So if you had a telescope at the center of a transparent Earth, you could resolve details about as big as a house lot up on the surface. - See more
For instance, Vega's exact declination is +38° 47' 01”
Declination (dec), which is measured in degrees (-90 for the south celestial pole, 0 for the celestial equator, and +90 for the north celestial pole). Partial degrees are usually described in terms of arcminutes (') and arcseconds (''). Think of declination as latitude

11. Uses 24 Hours
Based on 1 Rotation of the Earth
2 Stars that are 1 hour of R.A. apart, will cross the same point in the sky 1 hour of time apart.
0° Point: You just have to pick a point on the sky. This is what we picked.

12. Vernal Equinox?
It’s a moment in time, But It’s also a Location in the sky!! (the moment corresponds to when the sun crosses the celestial equator)

13. Equinox: Day and Night are same length
Equinox: Day and Night are same length. Both Northern and Southern Hemispheres get the same amount of light.

14. Vernal Equinox?
It’s a moment in time, But It’s also a Location in the sky!! (the moment corresponds to when the sun crosses the celestial equator)
The right ascension at the vernal equinox originally was in the constellation Aries and the point of crossing was known as the first point in Aries (now actually in Pisces because of precession

15. First Point of Aries
Actually it is now in Pisces

16. Right Ascension
Vega's right ascension is 18h 36m 56.3s
On Earth, 0° longitude has long been defined as a line engraved on a brass plate set in the floor under a position-measuring telescope at the Old Royal Observatory in Greenwich, England.
In the sky, 0h ("zero hours") right ascension is RA is measured from the point where the sun crosses the celestial equator at the Vernal equinox
Right Ascension (RA), which is usually measured in hours, minutes, and seconds. Think of this as terrestrial longitude extended out into space, then measuring it in hours makes a bit more sense (time zones). You could just as easily measure it in degrees, too, where 1 hour is 15 degrees. RA is measured from the point where the sun crosses the celestial equator at the March equinox

17. Equatorial System Look for: Celestial Pole (Polaris)
Stars Below the Horizon
Stars moving over time
Ecliptic
Celestial Equator
Vernal Equinox
Right Ascension: 0-24 hours
Declination: -90ᵒ to 90ᵒ

18. Right Ascension gets bigger going to the left, from our perspective in the Northern Hemisphere!! Opposite of azimuth

22. lines that run north-south on Earth are lines of longitude and when projected onto the sky, they become lines of right ascension.
the stars were used to measure time in the past, so right ascension (RA) is measured in terms of hours, minutes, and seconds and increases in an easterly direction.
lines that run east-west on Earth parallel to the equator are lines of latitude and when projected onto the sky, they become lines of declination.
Like the latitude lines on Earth, declination (dec) is measured in degrees away from the celestial equator, positive degrees for objects north of the celestial equator and negative degrees for objects south of the celestial equator. 

24. Betelgeuse
RA: 05h 55m  s
Dec: +07° 24′ 
Triangulum
RA: 02h 09m 32.52s
Dec: +34° 59′ 14.6″
Sirius
RA: 06h 45m  s
Dec: −16° 42′  ″

25. Betelgeuse Triangulum Sirius RA: 05h 55m 10.30536s
Dec: +07° 24′ 
Triangulum
RA: 02h 09m 32.52s
Dec: +34° 59′ 14.6″
Sirius
RA: 06h 45m  s
Dec: −16° 42′  ″

27. Equatorial Coordinate System
Declination
Right Ascension
What does it measure?
What are the units?
Where is the baseline? (the zero)
What would an example look like?
What does it relate to on Earth?

28. Work with your group to draw an accurate picture or sketch of the celestial sphere with both R.A. and Dec. represented

29. summarize
Bottom of page : in 2-3 sentences, answer this question using information from your notes.
How does the Equatorial system compare to the horizon system? Are there pros or cons to using one or the other?

30. If you haven’t got it already….
Find the Declination and Right Ascension of your adopted constellation as a fourth interesting fact.
It should be a range, as it covers an area of the sky, not a specific point
Write it down in your science journal

31. Quiz Tomorrow!!!!
If you need extra help on these two topics…There are two videos on our website.