Starry Monday at Otterbein

1. Welcome to Starry Monday at Otterbein Astronomy Lecture Series -every first Monday of the month- February 7, 2005 Dr. Uwe Trittmann

2. Today’s Topics • Famous Telescopes • Objects worthy to be observed • The Night Sky in February

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/ (Physics Dept.)

4. Telescopes • From Galileo to Hubble

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

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

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

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

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

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

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

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

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

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

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

16. 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

17. 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

18. Visiting Mauna Kea

19. Mauna Kea • Elevation: 14,000 ft. • Oxygen: 60% • Freezing on top, snorkeling at sea level • Road: strictly 4 wheels!

20. Mauna Kea • 325 observing days per year! • Darkest skies on the planet! Maui

21. The biggest Telescopes in the World

22. Sunset on Mauna Kea

23. Classifying Objects • Sun and Moon • Planets and their moons • Stars and Constellations • Variable stars • The Milky Way • Deep Sky Objects • Star Clusters (Open and Globular) • Bright and Dark Nebulae • Galaxies (used to be called nebulae also)

24. When to observe which Objects • The surface features on the Moon are best seen when the Moon is not full (nor new ) • Observe Jupiter’s four Galilean moons with binoculars whenever Jupiter’s up • Small telescope will show Saturn’s rings • Milky Way can be seen under dark skies (…but already in Madison county)

25. Deep Sky Objects • Usually faint and/or small • Best observed under dark skies/ moonless nights • Some are binocular objects, some require sizeable telescopes

26. Deep Sky Objects: Open Clusters • Classic example: Plejades (M45) • Few hundred stars • Young: “just born” • Still parts of matter • around the stars

27. Deep Sky Objects: Globular Clusters • Classic example: Great Hercules Cluster (M13) • Spherical clusters • may contain millions of stars • Old stars • Great tool to study stellar life cycle

28. Observing Stellar Evolution: Example

29. From the Rooftop Plejades in Taurus, Open Cluster M92 in Hercules, Globular Cluster 

30. Deep Sky Objects: Nebulae Classic example: Orion Nebula (M 42) • hot glowing gas Temperatures ~ 8000K • Made to glow by ultraviolet radiation emitted by young O- or B-type (hot) stars located inside • Color predominantly red, the color of a particular hydrogen emission line (“H”)

31. Friday Night • 27 seconds exposure

32. Friday Night • 87 seconds exposure

33. Dark Nebulae • Classic Example: Horsehead Nebula in Orion

34. Trifid Nebula(M20) Good example for dark dust lanes in front of an emission nebula

35. Deep Sky Objects: Planetary Nebulae • Classic Example: Ring nebula in Lyra (M57) (Here: “Eye of God” Nebula) • Dead, exploded stars • We see gas expanding in a sphere • In the middle is the dead star, a “White Dwarf”

36. Friday Night: Eskimo Nebula

37. Eskimo Nebula:close up

38. Deep Sky Objects: Galaxies • Classic example: Andromeda Galaxy (M31) • “Island universes” • Made out of billions of stars and dust • Very far away (millions of ly’s) • Different types: • Spiral, elliptic, irr.

39. Deep Sky Catalogues • Some of the best deep sky objects can be found in the Messier Catalogue (e.g. M 31) • Messier (around 1770) catalogued the objects not to confuse them with comets • There are 110 Messier Objects • Other catalogues: • NGC: new general catalogue (1880) lists 7800 objects • Caldwell list: 109 best non-messier objects • Herschel 400: from Herschel’s famous list, early 1800’s

40. The Night Sky in February • The sun is still very low in the sky -> long nights! • Winter constellations (Orion, Gemini, Taurus,…) contain many bright stars and objects • Saturn was in Opposition last month (i.e. at its brightest)

41. Moon Phases • Today (Waning crescent, 2%) • 2 / 8 (New Moon) • 2 / 15 (First Quarter Moon) • 2 / 28 (Full Moon) • 3 / 3 (Last Quarter Moon)

42. Today at Noon • Sun at meridian, i.e. exactly south

43. 10 PM Typical observing hour, early January • no Moon • Saturn!

44. Midnight Jupiter

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

46. North-East • Big Dipper points to the north pole

47. Due South • The Winter Constellations • Orion • Taurus • Canis Major • Gemini • Canis Minor

48. East Spring Constellations - Cancer - Leo - Hydra Deep Sky Objects: - Beehive Cluster (M44)

49. Mark your Calendars! • Next Starry Monday at Otterbein: March 7, 2005, 7 pm (this is a Monday ) • We’ll talk about Mars Missions and more… • Web pages: • http://www.otterbein.edu/dept/PHYS/weitkamp.asp (Obs.) • http://www.otterbein.edu/dept/PHYS/ (Physics Dept.)