1. A presentation by Mikaela harrington
THE SUN
A presentation by Mikaela harrington

2. What is a star? star (n.) \ ‘star \
“a self-luminous gaseous spheroidal celestial body of great mass which produces energy by means of nuclear fusion reactions.” – Merriam Webster Dictionary
Hydrogen atoms go through a process of nuclear fusion and turn into Helium in the core
Hydrogen fusion process can occur in up to 1/3 of a star’s radius
Up to ½ of a star’s mass can be accounted for by the interactions & atoms involved in hydrogen fusion

3. Star Classification
3 kinds of spectra used to classify stars: Continuous, emission, and absorption
Kirchhoff's Laws:
A hot opaque body, such as a hot dense gas, produces a continuous spectrum (a complete rainbow) of colors.
A hot, transparent gas produces an emission line spectrum – a series of bright spectral lines against a dark background.
A cool, transparent gas in front of a source of a continuous spectrum produces an absorption line spectrum – a series of dark spectral lines among the colors of the continuous spectrum.
Anywhere between billion stars in the Milky Way
Red star ≈ 5,000° F (surface temp.)
Yellow/white star ≈ 10,000° F (surface temp.)
Blue Star ≈ 71,540° F (surface temp.)

4. (MORE!) Star classification
OBAFGKM – classification scheme used by astronomers
Spectral type tells you about surface temperature of the star

5. What class is our sun? Yellow dwarf star (G2V star)
4.3 billion years old
Expected to live another 7 billion years
Predicted to become red giant before collapsing into white dwarf

6. Size of the sun 864,338 miles in diameter
Earth = 7,918 miles in diameter
Angular size of Sun = 0.53 degrees (how large it appears to a human eye)
Average distance of Earth to sun = 92,955,807 miles (average of different distances due to orbit)
1 AU (astronomical unit) = million miles (how far the Earth is from the sun)
Apparent magnitude of (measure of the star’s flux received by humans on Earth)

8. What does it actually look like?
Sketch done by Erika McGinnis

9. Don’t! (with your naked eye or an unfiltered telescope that is)
How to observe the sun?
Don’t! (with your naked eye or an unfiltered telescope that is)

10. Safe observation practices
“Safe” observation is classified as having 99% or more of sunlight filtered out.
For telescopes and binoculars, NEVER put filters at ends of eye pieces (the concentrated light will destroy them).
Different methods of observation:
Pinhole Projection
Telescopic or Binocular pinhole projection
Eclipse Glasses
High End Telescope Solar Filters

11. Pinhole Projection method
Find a plain, blank, white sheet of paper and position it where you want to project the image of the Sun.
Take a thick piece of cardboard and make a small, round hole in the center.
Hold or fix the piece of cardboard in a position where you can see an image being projected onto the paper.
If you want the image to be larger, move the cardboard further away from the paper.

12. Telescopic/binocular pinhole projection
Set up a plain, white piece of paper where you want to observe the image of the sun.
For telescopes, ensure that you secure a piece of cardboard around the body of the scope while facing away from the sun so that no direct sunlight is hitting your paper.
For binoculars, watch the projection sheet while moving the binoculars around to get the right positioning for the image.

13. Eclipse glasses Don’t try to make home-made pair
ISO   approved glasses only
$8.50 around May, 2017
Visible Light
Eclipse Glasses Lens
UVA Rays
Excess Sunlight
UVB Rays

14. Hydrogen-Alpha filter ($55-$600)
White Light filter
($35-$100)

15. 11 year solar cycle 5 ½ years in “Solar Minimum”
5 ½ years in “Solar Maximum”
Sunspots act as indicators for a change in period
Sunspot: dark spot visible on Sun’s surface that is caused by intense magnetic activity

16. Solar Flares

17. For a better explanation…

18. References
Anon, (n.d.). [image] Available at: [Accessed 21 Sep. 2018]. Astro.unl.edu. (n.d.). Spectral Classification - Hertzsprung-Russell Diagram - NAAP. [online] Available at: [Accessed 21 Sep. 2018]. Astronomynotes.com. (2010). Properties of Stars. [online] Available at: [Accessed 18 Sep. 2018]. En.wikipedia.org. (2018). Angular diameter. [online] Available at: [Accessed 18 Sep. 2018]. En.wikipedia.org. (2018). Stellar nucleosynthesis. [online] Available at: [Accessed 21 Sep. 2018]. Google.com. (2018). how big is the sun - Google Search. [online] Available at: me..69i57j69i60l2j0l3.2104j0j4&sourceid=chrome&ie=UTF-8 [Accessed 18 Sep. 2018]. Google.com. (2018). how far from earth is the sun - Google Search. [online] Available at: +is+the+sun&aqs=chrome..69i57j0l5.4906j0j4&sourceid=chrome&ie=UTF-8 [Accessed 18 Sep. 2018]. McGinnis, E. (2008). Solar Illustration. [image] Available at: flares.jpg [Accessed 18 Sep. 2018]. NASA Captured a Huge Solar Prominence Erupting from the Sun. (2002). [image] Available at: [Accessed 18 Sep. 2018]. Nineplanets.org. (2018). The Sun - How Big is the sun. [online] Available at: [Accessed 17 Sep. 2018].

19. References (Part 2)
Anon, (n.d.). [image] Available at: solar-corona-solar [Accessed 20 Sep. 2018]. Cain, F. (2009). Temperature of Stars - Universe Today. [online] Universe Today. Available at: [Accessed 20 Sep. 2018]. Cain, F. (2008). What Kind of Star is the Sun? - Universe Today. [online] Universe Today. Available at: [Accessed 21 Sep. 2018]. Freudenrich, C. (n.d.). How Stars Work. [online] HowStuffWorks. Available at: [Accessed 20 Sep. 2018]. Goddard, N. (2011). NASA | X-Class: A Guide to Solar Flares. [image] Available at: [Accessed 20 Sep. 2018]. Imhoff, C. (n.d.). All About Stars | Scholastic. [online] Scholastic.com. Available at: [Accessed 19 Sep. 2018]. Masetti, M. (2015). How Many Stars in the Milky Way?. [online] NASA Blueshift. Available at: [Accessed 19 Sep. 2018]. Merriam-webster.com. (n.d.). Definition of STAR. [online] Available at: [Accessed 19 Sep. 2018]. Sky & Telescope. (2013). How to Look at the Sun Safely and Enjoy Solar Eclipses | Sky & Telescope. [online] Available at: [Accessed 18 Sep. 2018].

20. References (Part 3)
Anon, (n.d.). [image] Available at: [Accessed 21 Sep. 2018]. Anon, (n.d.). [image] Available at: [Accessed 21 Sep. 2018]. Anon, (n.d.). [image] Available at: [Accessed 21 Sep. 2018]. Anon, (2017). [image] Available at: cdn.com/media/2017/08/14/USATODAY/USATODAY/ EclipseGlasses.png [Accessed 21 Sep. 2018]. Chow, D. (2011). How the Sun's 11-Year Solar Cycle Works. [online] Live Science. Available at: [Accessed 21 Sep. 2018]. Goertzen, J. (2017). How the lenses in solar eclipse glasses protect your eyes from the sun. [online] Orange County Register. Available at: your-eyes-from-the-sun/ [Accessed 21 Sep. 2018].

21. Thanks for your attention
Any Questions/comments?