1. PHYS178 Other Worlds A/Prof. Orsola De Marco 9850 4241 orsola@science.mq.edu.au http:/web.science.mq.edu.au/~orsola/ click on PHYS178 teaching

2. PHYS178 structure 7 weeks, 21 hours for the Solar System (by Orsola De Marco) 3 weeks on the details of the Solar System formation (by Andrei Gilchrist) 3 weeks on extrasolar planets (by Quentin Parker)

3. Assignments For the SS part of the course: 5, weekly (short) assignments handed out via web on Tuesday afternoons. Returned in person on following Monday. Content of assignments discussed in class on Monday mornings. Grades averaged to form the assignment part of the course (20% of final grade). Class participation also rewarded via additive grades.

4. Practical There is one practical posted on the website. You can do it in your own time on any clear night. There is a minimum requirement of 5 observations between August 24th and September 11th. Due in on September 11. You will need to go to the Observatory once and do a one page write-up. This is 10% of the class grade.

5. Tutorials Tutorials start on Monday 10 August (group 1) or Tuesday 11 August (group 2). Class: C5C 240. (3% points for showing up). Class 1: reading a series of articles on the recent Jupiter impact. Discussing the article within a group. Class 2: Preparing a short presentation electronically (bring your computer) or on transparencies (provided). Class 3: present in front of class (2 minutes each). This presentation is marked (7% of total mark). Class 4: prepare an article of your choice (on the topic of Solar System science) and present in class. Class 5: presentations. The mark is 10% of total.

6. Office hours Office Hours: best way to contact me: e-mail (orsola@science.mq.edu.au) Second best, make an appointment via e-mail. Third best come to my office right after class. If you really must, come any time.

7. Introductions Write on a white piece of paper (anonymous): Name in capital letters, Intended degree, Motivation for taking this course, Have you taken an Astronomy course before? If so, what course was it? Please write on a separate paper with no name, the answer to the following questions: 1. What is the name of the equation E = mc 2 ? 2. If x+y=3 and xy=2, can you obtain the values of x and y (just yes or no – and be honest)? 3. Why is the sky blue? 4. What is the Sun? 5. What force makes planets orbit the Sun?

8. Course Outline 1. The Solar System in context and the celestial sphere 2. Why the sky looks the way it does. Early observers and the scientific method. 3. The terrestrial planets: Earth 4. The terrestrial planets: Mercury, Venus and Mars. 5. The gas giants: Jupiter, aurorae and tides. 6. The gas giants: Saturn, Uranus and Neptune and their rings.

9. This and next week’s outline Space and time: sizing up the Universe. Orienting yourself in the celestial sphere. What do you see when you look up: the Sun, the Moon, the planets … … why they look they way they do, why they are where they are, why they move they way they move … How to impress your girlfriend, boyfriend or grandmother with your knowledge of the heavens. The early observers (Ptolemy, Tycho, Copernicus and Galileo) and the scientific method.

10. The Solar System in context Powers of Ten http://www.youtube.com/watch?v=A2cmlhfdxuY Learning Points: Powers of ten. Log scale Size of the Universe

11. Scales of the Universe Units of the Cosmos: – Solar Radius (Ro) – The astronomical unit (AU) – light years – parsec (=3.26 ly; pc) – centimeter (!) The Scientific notation: –1 = 10 0 –10 = 10 1 –100 = 10 2 –100,000 = 10 5 –When using cm, you see a lot of, e.g., 10 13 !

12. And while we are at it … prefix multipliers: 10 = deca 100 = hecto 1000 = kilo (K) 1,000,000 = 10 6 = million = mega (M) 10 9 = billion = giga (G) 10 12 = triollion = tera (T) 10 15 = million trillion (?) = peta (P) (exa zetta yotta)

13. And since we are having so much fun…. prefix multipliers: 0.1 = deci 0.01 = centi 0.001 = milli (m) 0.000001 = 10 -6 = a millionth = micro (  ) 10 -9 = a billionth = nano (n) 10 -12 = a triollionth = pico (p) 10 -15 = a millionth trillionth (?) = femto (f) (atto zepto yocto)

14. Earth Radius: 6357 - 6378 km or 6.4 x 10 8 cm (Concept of approximation)

15. Sun Radius 696,000 km or 6.96 x 10 10 cm or 1 Ro ~100 x Earth

16. Jupiter Radius 69,911 km or 6.99 x 10 9 cm or ~0.1 Ro ~10 x Earth

17. Solar System Radius (Pluto) 40 AU 6.0 x 10 9 km 6.0 x 10 14 cm 40 x Earth-Sun

18. Our Galaxy Radius ~15,000 pc or 15 kpc 4.6 x 10 22 cm 7.7 x 10 7 x SS

19. LMC: 50 kpc SMC: ~60 kpc M31: 2.5 Mpc Virgo Cluster: 18 Mpc Galaxy – LMC/SMC

20. Orienting yourself in the night North, South, East and West Angular separations Constellations and their meaning

24. The Constellations Stars in a constellations are not grouped in space, they are close because of chance alignment.

25. Constellations Names and the Zodiac Many constellations were named by the Greeks (including some southern ones which were more northern 2000 years ago). Constellations names are usually Latin (e.g., Centaurus). Stars in a constellation are called with Greek letters according to their brightness (  being the brightest), followed by the constellation name in the genitive (e.g.,  Centauri, also abbreviated  Cen). The horoscope…

26. The day: The spin of Earth

28. The celestial sphere is an imaginary sphere centered on the Earth, whose poles are the same as the Earth’s poles and whose equator is the projection of Earth’s equator.

29. At the North Pole: how do stars move during the night?

30. And at the Equator?

31. And where is this observer?

34. The North Celestial Pole

35. The South Celestial Pole To find South at night, look for the South celestial pole and draw a line down to your horizon. That is South.

36. Latitude and Longitude What is the reference frame? Latitude: equator Longitude: the Greenwich meridian.

37. Measuring Latitude Your latitude North/South is the same as the altitude of the North/South celestial pole (easy to measure in the North, where Polaris marks the spot!)

39. The seasons

41. In the Southern hemisphere at noon the Sun is North of the Zenith. You can find South by tracing a line from the Sun to the horizon or by following your shadow backwards.

44. The night sky over the year

47. Celestial coordinates Anybody remember what this picture is from? Anybody remember what she says when she hears the repeating source?

48. (Woman sitting in car) “Oh Shit” music … (Jumps into car, talks on VHF) “Right ascension, 18 hours, 36 minutes, 56.2 seconds declination, + 36 degrees, 46 minutes, 56.2 seconds” (pause) “CONFIRM?”

49. A coordinate system They are the coordinates of Vega! We need coordinates for stars just like we need coordinates for locations on earth. They need to be time and place independent.

50. Latitude and Longitude What is the reference frame? Latitude: equator Longitude: the Greenwich meridian.

51. Earth’s orbit around the Sun Note: Earth’s equator is tilted with respect to the orbital plane

52. Earth’s orbit around the Sun

53. Let’s pretend that the Earth is in the middle “The Sun’s orbit around Earth”

54. Let’s tilt our head till Earth’s axis is parallel to the up-down direction “The Sun’s orbit around Earth”

55. From Earth’s perspective … Celestial equator Ecliptic The vernal equinox: 

56. Right Ascension and Declination 

57. 

58. 

59. 

60.  Dec

61. Right Ascension and Declination  RA

62. A star’s coordinate are given as two sets of numbers (measuring angles) called: Right Ascension & Declination they look like this 13 h 12 m 13.3 s +60 o 45’ 33.2’’

63. Hours and degrees : 0 o =360 o 90 o 180 o 270 o 0 h =12 h 3h3h 6h6h 9h9h 13 h 12 m 13.3 s +60 o 45’ 33.2’’

64. Precession

68. Hipparcos lost star catalogue