1. The Great American Solar Eclipse 8/21/2017
Solar Eclipse Workshop
May 20, 2017
Gary J. Senn, PhD -
Darlene Smalley –

2. The Blowfish are a “summer collegiate” team playing in the Coastal Plain League. It’s basically for college guys to get a chance to play with wooden bats as they get ready to hopefully get drafted.

3. What is an eclipse?
Eclipse: Obscuring of one solar body. It is all in the name.
Solar Eclipse: Sol or the Sun
Lunar Eclipse: Luna or the Moon
- SME Syzygy
- SEM Syzygy
Syzygy

4. How do eclipses occur? Lunar eclipse Solar eclipse Moon phase? Order?
Full moon
Order?
SEM
Solar eclipse
New moon
SME

5. Types of eclipses
Partial
Total
Annular
Hybrid

6. Moon Perigee & Apogee

7. Sun Perigee & Apogee

8. Apparent sizes – Sun, Moon

9. ~1/3 Partial Eclipses ~1/3 Total Eclipses ~1/3 Annular Eclipses …and a dash of Hybrid Eclipses
Why?
Source: NASA - Eclipse 99 - Frequently Asked Questions

10. Lunar eclipse from space
Image Credit:

11. Solar eclipse from space
Image Credit: Wikimedia Commons

12. How often do eclipses occur?
Why not every month?
Image Credit: AstronomyOnline.org

13. Saros /ˈse räs/ - Timing of eclipses
Chaldeans BC
Background - types of months
Sidereal Month (star to star) = days = 27d 7h 43m 11.5 s
Synodic Month (new moon to new moon) = days = 29d 12h 44m 03s
Anomalistic Month (perigee to perigee) = days = 27d 13h 18m 33s
Draconic Month (node to node) = days = 27d 05h 05m 36s
Saros /ˈse räs/ – Ancient Greek defined as, “a measure and a number among Chaldeans.” Based on observations of eclipse cycles.
- Babylonian word, “saru” meaning Might be a misinterpretation of this number.
Sidereal month days (27 d 7 h 43 min 11.5 s). Time to get back to the same spot in the sky, the celestial sphere or the
International Celestial Reference Frame (ICRF)
Latin = Sidera. English = Stars
Synodic /səˈnä dik/ month –
Latin = Synod. English = Meeting
Anomalistic /uh-nom-uh-lis-tik/ month
Anomoly – something different or abnormal – going from perigee to perigee is abnormal from the observer’s perspective
Draconic \drə-ˈkä-nik\ month – or Nodical month. Named for the dragons that live in the nodes and eat the sun or moon during eclipses
The word Saros derives from the Babylonian term "sar" which is an interval of 3600 years. It was never used as an eclipse period until English astronomer Edmund Halley adopted it in According to R. H. van Gent, Halley "...extracted it from the lexicon of the 11th-century Byzantine scholar Suidas who in turn erroneously linked it to an (unnamed) 223-month Babylonian eclipse period mentioned by Pliny the Elder (Naturalis Historia II.10[56])."

14. Saros /ˈse räs/ One cycle in series repeats every:
6,585.3 days (18 years 11 days 8 hours)
223 Synodic Months = days = 6585d 07h 43m
239 Anomalistic Months = days = 6585d 12h 54m
242 Draconic Months = days = 6585d 08h 35m
Saros /ˈse räs/
Anomalistic /uh-nom-uh-lis-tik/
Synodic /səˈnä dik/
Draconic \drə-ˈkä-nik\

15. Saros Series Characteristics
Duration: 1226 – 1550 years
Number of Eclipses: 69-87
Odd Saros Numbers: Solar Eclipse
Near Moon’s ascending node
Begins near north pole
Shift southward
Even Saros Numbers: Solar Eclipse
Opposite
Moon, opposite from Sun
Saros /ˈse räs/

16. Saros 145 – 8/21/17 Eclipse Began 1639 – partial near north pole
First Annular 1891
First total 1927
Last total 2648
End 3009 – partial near south pole
Selected series of , 1909, 1927, 1945, 1963, 1981, 1999, 2017, 2035 and 2053
Saros /ˈse räs/

17. Saros /ˈse räs/

19. Saros 136 – longest eclipses of 20th and 21st centuries
Even number – South to North
Saros /ˈse räs/

20. Saros 145 Includes 8/21/2017 Eclipse Odd number – North to South
greatamericaneclipse.com
Saros /ˈse räs/

21. 21st Centurey Solar Eclipses

22. 21st Century Solar Eclipses
Currently 39 active Saros series
Numbered 117 to 155