I created and shared this presentation about Solar Eclipses at the Annual IPS-NYP Astronomy Retreat at Nongsa Point on Batam in 2011.

1. by Koh Joo Beng

2. Overview
• The Sun
• History of Eclipses
• Geometry
• Observing
• Phases
• Oddities
• Videos/Slideshows
• Upcoming Eclipses
• Resources

3. The Sun
Volume: 1,300,000 Earths
Mass: 333,000 Earths
Power: 4 x 1026 W
(50,000 billion reactors)
0.0005 % reaches Earth

4. “Parts” of the Sun

5. CME!
7 Jun 2011

6. Photon’s “walk”
• Photon (initially gamma ray) is
created by thermonuclear
fusion
• Reaches convective region
only after 20,000~100,000 yrs!
• Collides with others along the
way and loses energy to
become visible light photon
• Radiates away at the surface
of the Sun
• Takes only 8 minutes to get to
Earth

7. Brief History of
Eclipses

8. Geometry of Eclipses
Not to Scale!

9. Types of Solar
Eclipses
• Total or Annular? Is due to
the elliptical orbit of the
Moon (and also the Earth)
– Moon at apogee = Annular
Eclipse.
Not to Scale! – At perigee = Total Eclipse
• Total Eclipse over a
particular city is once in 370
years!
Total Annular Partial

10. A Coincidence?
• Sun is 400 times larger than the Moon
• Sun is 400 times farther than the Moon
• Both objects subtend angle of 0.5 degrees!
• Is physics involved? Or just pure luck?
• Moon is receeding 4cm/yr.
• 100 million years ago, no annular eclipses
• 100 million years later, no more total
eclipses!
• Can’t see a total eclipse on any other planet.

11. Why not 13 eclipses a
year?
• On Youtube at http://youtu.be/E1B3RLf1A1s
• Or search Youtube for “Solar Eclipse
Educational Video”
• Or click here.

12. Observing an Eclipse
Never look directly
at the Sun,
Except DURING
especially with a
moment of telescope
TOTAL ECLIPSE
Instant and
irreparable eye
damage can occur.

13. Observing phases
of an Eclipse
Shade 14 Welder’s glass

14. Phases of a
Total Eclipse
• 4 “Contacts” depending on which “limb” or
edge of Moon-Sun is in contact.
1st Contact 2nd Contact 3rd Contact 4th Contact

15. Diamond Rings &
Bailey’s Beads
• Possible to see only at 2nd and 3rd contact

16. Oddities

17. The Corona!
1/64 sec
2 sec
Composite

18. Videos/Slideshows

19. China
Total Eclipse 2008
• On Youtube at http://youtu.be/Gm3EVERbx_c
• Or search Youtube for “Joo Beng’s Total Solar
Eclipse 2008”
• Or click here.

20. Slideshows
• Kenya 2010
• South America 2010

21. Annular Eclipse
Kenya 2010

22. Easter Island
Total Eclipse 2010
• On Youtube at http://youtu.be/OWgOmHm6JHs
• Or search Youtube for “Easter Island Solar
Eclipse 2010”
• Or click here.

23. Coming Solar
Eclipses
• 2011
– 1 Jul : Partial Eclipse – Antarctica
– 25 Nov: Partial Eclipse – Antarctica
• 2012
– 20 May : Annular Eclipse – USA-Japan-Fuzhou
– 13 Nov : Total Eclipse – Pacific-Australia
(Cairns)
• 2013
– 10 May : Annular Eclipse – Pacific-Australia
– 3 Nov : Hybrid Eclipse – Africa

24. Total Eclipse
13 Nov 2012

25. Eclipse Resources
• MrEclipse.com : http://www.mreclipse.com/MrEclipse.html
– Ultimate resources for eclipses
• NASA Eclipse website : http://eclipse.gsfc.nasa.gov/eclipse.html
– For lots of Technical Data
• Java Solar Eclipse Explorer :
http://eclipse.gsfc.nasa.gov/JSEX/JSEX-AU.html
– Calculator to determine eclipses viewable from Singapore (or any other
city)
– Previous Total Eclipse on 4 Mar 1821!
– Next Annular Eclipse on 26 Dec 2019!
– Next Total Eclipse on 5 Jul 2168!
• Eclipse in a Different Light :
http://sunearthday.nasa.gov/2006/multimedia/storyteller.php
– Eclipse stories, folklore

26. Questions?

27. Thank you!!
If you have any questions,
do send an email to
joobeng@astrobargains.com

28. The End

29. Backup material

30. Do you want to know more
about Astronomy?
• Basics of Astronomy • Astronomy Equipment
– Astronomical vocabulary, distance units, parsec, – Refractors, Reflectors, Cassegrains and other
light year telescope designs
– The motion of the planets, elliptical orbits, – Telescope mounting systems, Alt-Az vs
Keppler’s laws. Equatorial.
– Seasons, and why they occur, Earth’s tilt. – Astrophotography, Polar alignment, Focusing in
– The Lunar Cycle the dark, CCD, Image processing
– Eclipses, how they occur, differences between – Telescopes in Space, Hubble, Chandra.
Lunar and Solar eclipses – Large telescopes of the World, Keck, VLSI, VLT,
– Local coordinates, Celestial coordinates, Galactic ELT,
coordinates, • Solar system overview and Birth Theory.
– Newton ’s Laws – Earth
– Nature of light – The Moon
• History of Astronomy – The Sun as a star.
– The Scientific Method – Mercury, Venus, Mars
– Ancient astronomers, Galileo, Copernicus, Tycho – Jupiter, Saturn, Uranus, Neptune
Brahe – Pluto, discussion of Pluto being a minor planet.
– Archaeastronomy – Comets and asteroids, Meteorites.
• Intermediate Astronomy • Cosmology
– Colour of Stars, Relationship of Colour to – The Big Bang, Big Crunch
temperature – Einstein’s Theory of Relativity, Special, General
– Spectral lines and chemical composition – Relativistic Doppler Shift
– The Inverse square law of brightness, H-R – Cosmological Constant
Diagram
– The Doppler effect – Hubble’s Law
– Multi-wavelength astronomy, Radio, X-ray, – Expansion of the Universe
Infrared, Gamma-ray. – Cosmic Microwave Background
– Black Holes, Quasars and Active Galaxies, – COBE, WMAP
Neutron stars, Pulsars, White Dwarfs • And much much more....
– Galaxies, The Milky Way

31. To purchase your own telescope
or other astronomy-related equipment,
visit www.astrobargains.com

32. Other useful links
• Stellarium - Planetarium program www.stellarium.org
• Celestia – Space Simulation www.shatters.net/celestia
• Singastro – Singapore’s astronomy forum www.singastro.org
• Singastro Wiki - Wiki for Astronomy Beginners in Singapore
www.singastro.org/web/mediawiki
• Astronomy.sg – Singapore astronomy portal
www.astronomy.sg
• Printable Sky Charts – Cartes du Ciel
www.stargazing.net/astropc
• Interactive Sky Charts
– From Sky & Telescope :
http://www.skyandtelescope.com/observing/skychart/
– Astronomy Magazine :
http://www.astronomy.com/asy/stardome

33. Overview
• Objective: Give audience an appreciation of the beauty of Sun, and share the • Phases of the eclipse
thrill of a total solar eclipse • 1st to 4th contacts
• Format : Slides, videos, with narration. Use Starry Night to show. Minimal • Diamond ring, Bailey’s Beads
interaction. • Corona
• Oddities of eclipses
• Overview of Sun – parts of the Sun • Shadow bands – light through fluid.
• Photosphere, Chromosphere, Corona – thin hot atmosphere of Sun. Shaped by • Solar crescents
magnetic field. • Shadow racing from West to East
• Prominences – plumes of gas, Sunspots, Filaments, • Twilight effect – setting sun colours.
• How long it takes photon to emerge – solar walk • Videos of eclipses
• Stories of eclipses • Mongolia
• Dragon eating Sun • Easter Island
• Sun-Moon lovers fighting • Kenya
• Sun-Moon Lovers hiding in darkness • Coming eclipses
• Sun angry, hiding for a while • Annular eclipse – May 2012, USA
• 585BC – Central Turkey Meades and Linions, battle of 5 yrs, was predicted by • Total eclipse – Nov 2012, Fiji
astronomers, but soldiers didn’t know. Eclipse was sign that they should not fight.
Cemented bond with double marriage. • Solar eclipse resources
• 1919 Evidence for General Theory of Relativity – Arthur Eddington, • Mr Eclipse – Fred Espenak
• Geometry of eclipses • Eclipse path maps
• Sized by chance? Moon receeding…4cm/yr. 100m yrs no more eclipses. 100m yrs • Total and annular path forecasts
ago, no annulars. Can’t even see corona, so not as fun. No other planet can ever
see a total eclipse (e.g. Mars moons too small, Jupiters too big) • Omitted:
• New Moon. • Planning the eclipse
• Partial, Annular vs Eclipse, Hybrid • Prioritize one feature to look at.
• Orbit is elliptical – variation of Moon at Apogee (smaller) and Perigee (larger)
• Earth’s orbit also elliptical
• Don’t photograph
• Hybrid eclipse – Annular-Total-Annular • Enjoy
• Video – why eclipses don’t occur 13 times a year • Timing, practice practice practice.
• Timing of eclipses – few seconds – max 7.5 min. Mostly 2min. • Solar photography/videography
• 1 in 360 yrs eclipse is over a city. So have to travel to see it. • Built-up corona – insufficient dynamic range in cameras
• Observing eclipses • Eclipse sequencing - photoshop
• Warning - Power of the Sun. Do not look at the Sun without protection. Melted • Equipment
eyepiece cap? • Zoom
• Filters, not during totality • Camera
• Always before the objective, never at the eyepiece. • Exposure settings
• When telescopes pointed at Sun, must be attended. • Focus
• Solar glasses • Creative eclipse photos
• Shade 14 Welder’s glass • Name eclipse – Singapore?
• Telescope projection - refractors
• Pin-hole projection •
• Sunspotter
• Bucket of water?