1. Starry Monday at Otterbein Astronomy Lecture Series -every first Monday of the month- January 3, 2005 Dr. Uwe Trittmann Welcome to

2. Today’s Topics Telescopes The Night Sky in January

3. Feedback! Please write down suggestions/your interests on the note pads provided If you would like to hear from us, please leave your email / address To learn more about astronomy and physics at Otterbein, please visit –http://www.otterbein.edu/dept/PHYS/weitkamp.asp (Obs.)http://www.otterbein.edu/dept/PHYS/weitkamp.asp –http://www.otterbein.edu/dept/PHYS/ (Physics Dept.)http://www.otterbein.edu/dept/PHYS/

4. Telescopes From Galileo to Hubble

5. Telescopes Light collectors Two types: –Reflectors (Mirrors) –Refractors (Lenses)

6. Refraction Light travels at different speeds in vacuum, air, and other substances When light hits the material at an angle, part of it slows down while the rest continues at the original speed – results in a change of direction –Different colors bend different amounts – prism, rainbow

7. Refraction Lenses use refraction to focus light to a single spot

8. Reflection Light that hits a mirror is reflected at the same angle it was incident from Proper design of a mirror (the shape of a parabola) can focus all rays incident on the mirror to a single place

9. Reflecting Telescopes

10. Exploring our Telescopes Typical Questions: –What type of telescope is it? –How big is it, i.e. what is its biggest optical device? –What is its focal length? –What is the focal length of the eyepiece? –What is its magnification? –Try to focus on an object. Describe the image. –If the telescope is on a mount: How many axes does the mount have? Does it have a motor? What is the type of mount?

11. Magnification Magnification of a telescope is determined by the ratio of the focal length of the main optical device F and the focal length of the eyepiece f: magnification= F / f The longer F the more magnification The shorter f the more magnification

12. Newtonian Telescope Long tubes (approx. focal length) Open at front Eyepiece on side

13. Schmidt-Cassegrain Telescope (CAT) Very compact & easy to use Closed (Corrector plate) Resonably priced

14. Refractor Two lenses -> inverted image Long tube (approx. focal length of objective) Usually pretty expensive

15. Binoculars Erect image -> good for terrestrial viewing Prisms needed to produce erect image Typical specs: 8x60, means magnifies 8x and objective lens is 60 mm in diameter

16. A good starting point A pair of binoculars and a star map will keep you busy for a long time – anywhere! –constellations –Planets –Moon –Orion nebula –Andromeda Galaxy –star clusters –…

17. The Night Sky in January The sun is very low in the sky -> long nights! Winter constellations (Orion, Gemini, Taurus,…) contain many bright stars and objects The Earth is closest to the sun! Saturn is in Opposition (i.e. at its brightest)

18. What’s up in the night sky? The Celestial Sphere An imaginary sphere surrounding the earth, on which we picture the stars attached Axis through earth’s north and south pole goes through celestial north and south pole Earth’s equator Celestial equator

19. What’s up for you? Observer Coordinates Horizon – the plane you stand on Zenith – the point right above you Meridian – the line from North to Zenith to south

20. …depends where you are! Your local sky – your view depends on your location on earth

21. Look North in Westerville

22. Look North on Hawai’i

23. Sun and Moon From: wunderground.com

24. Moon Phases Today (Waning gibbous, 49%) 1 / 10 (New Moon) 1 / 17 (First Quarter Moon) 1 / 25 (Full Moon) 2 / 2 (Last Quarter Moon)

25. Today at Noon Sun at meridian, i.e. exactly south

26. At Sunset

27. 10 PM Typical observing hour, early January no Moon Saturn!

28. Zenith High in the sky: Perseus and Auriga with Plejades and the Double Cluster

29. North- East Big Dipper points to the north pole

30. South- West The Autumn Constellations W of Cassiopeia Big Square of Pegasus Andromeda Galaxy

31. “PR” Foto Actual look

32. Due South The Winter Constellations –Orion –Taurus –Canis Major –Gemini –Canis Minor

33. Saturn Day of opposition: January 13, 2005 Distance at opposition: 8.094 A.U. or 748 million miles Apparent diameter: 20” or 1/90 that of the moon Actual diameter: 120,000 km or 10 Earths

34. Changing Ring Opening 1998 1997 1996 2000 1999

35. Titan – Saturn’s largest moon STRANGE TITAN: Get ready for two of the strangest hours in the history of space exploration. That's how long it will take the European Space Agency's Huygens probe to parachute to the surface of Saturn's largest moon Titan on January 14th. Huygens will sample Titan's atmosphere, photograph its bizarre terrain, listen for alien sounds and, possibly, splash down in a liquid methane sea.

36. Comet Machholz Comet Machholz (C/2004 Q2) is approaching Earth and gliding through the constellation Taurus. It's easy to find. Go outside and look south between 9 and 10 PM. To the unaided eye, it looks like a faint and fuzzy green star. Through a small telescope, you can see the comet's two tails.

37. Mark your Calendars! Next Starry Monday at Otterbein: February 7, 2005, 7 pm (this is a Monday ) Web pages: –http://www.otterbein.edu/dept/PHYS/weitkamp.asp (Obs.)http://www.otterbein.edu/dept/PHYS/weitkamp.asp –http://www.otterbein.edu/dept/PHYS/ (Physics Dept.)http://www.otterbein.edu/dept/PHYS/

38. Famous Telescopes - Galileo Galileo’s first telescope was 3x magnifying his last one 32 x

39. Famous Telescopes -Newton First Reflector ever Built around 1670 After this: gargantuan Telescopes!

40. Famous Telescopes - Hevelius Rooftop observatory of Johannes Hevelius (1670)

41. Famous Telescopes - Hevelius 60 inch ^ 140 inch 

42. Famous Telescopes - Herschel Herschel detected Uranus (1781)

43. Famous Telescopes – Lord Ross 72 inch Reflector built during potato famine in Ireland Largest Telescope until Mt Wilson (1917)

44. Famous Telescopes – Yerkes Largest Refractor Telescope ever 40 inch lens Built 1897

45. Famous Telescopes – Mt Palomar 5 Meter Telescope – Huge and heavy mirror On Mt. Palomar in California

46. Famous Telescopes – Hubble Space Telescope In orbit around earth No limitations due to earth’s atmosphere Brilliant pictures

47. Famous Telescopes – Arecibo Radio Telescope Located in Puerto Rico 300m diameter Receives Radio waves Built 1963 SETI

48. Famous People Hubble in prime focus of Einstein visits Mt Wilson Mt Palomar. Hubble detected the Expansion of the Universe  Proof of Einstein’s General Relativity Theory

49. Largest Earth-Based Telescopes Keck I and II, Mauna Kea, Hawai’i –36  1.8 m hexagonal mirrors; equivalent to 10 m –Above most of atmosphere (almost 14,000 ft ASL) –Operating since 1993

50. Visiting Mauna Kea