by Brenda Rogers and James Brelsford

1. Stars Down Under by Brenda Rogers and James Brelsford

2. The Milky Way of the Southern Skies The Milky Way of the Southern Skies The human eye can only detect about 3,000 stars above the horizon of each hemisphere. We are going to look at a few constellations and special stars below the equator.

3. North Celestial Pole “Polaris” Celestial Equator South Celestial Pole Near constellation “Octans” We once thought there was no south pole star. The Hubble Space Telescope changed that! However, the south pole star they found is so faint, it is difficult to see with the eye: Sigma Octantis or South Star.

4. The South Pole Star is the very faint sigma Octantis, barely visible to the naked eye. We can’t see it, so we don’t use it.

5. How you see it in the Northern Hemisphere How you would see it in the Southern Hemisphere If you travel south of the equator, all the constellations you are familiar with in the northern hemisphere ...if you can see them, will be appear to be upside down.

6. You will not even see the Big Dipper unless it is Spring and youare at the equator.

7. Circumpolar stars never set. They appear to go around and around the pole year in, year out. Are the stars moving? Or our planet? Many of the constellations we will see tonight are circumpolar constellations.

8. Centaurus Centaurus is one of the largest constellations in the sky. Around 150 A.D. it was one of the 48 constellations listed by Ptolemy. Today it is one of the 88 modern constellations.

9. Centaurus Although it looks more like a camel, The Greeks called this pattern of stars a centaur.

10. Inside Centaurus Omega Centauri Unusual Globular Cluster Omega Centauri is the largest and brightest globular star cluster in the sky. It is so large you can see it with just your eye but it is beautiful through binoculars! Almost all the time, globular clusters are huge groups of tens of thousands to one million stars. Usually globular clusters only have older stars. But this one is different. It has stars of all ages. DEMO

11. Inside Centaurus Galaxy Cluster Abell S0740 This galaxy is home to thousands of globular clusters seen throughout the galaxy’s halo. Some of these galaxies are 450 million ly away.

12. Inside Centaurus The Alpha Centauri System, The Closest Star System to Our Sun beta Centauri Hadar • a blue giant • almost 400 ly • among top ten • brightest stars alpha Centauri Rigel Kent 4.3 ly

13. Inside Centaurus Closest Star System beta Centauri alpha Centauri alpha Centauri is a yellow trinary, beta Centauri is a blue binary. Proxima Centauri , 4.2 LY away, is part of the alpha Centauri system. It is a red dwarf star, seen only with a scope. DEMO

14. Size Comparison Proxima Centauri is a dying red dwarf.

15. Centaurus The Pointers Inside the constellation Centaurus are the “Pointer Stars.” But what are they pointing to?

16. Southern Cross or Crux Crux, the Southern Cross, is the most familiar constellation in the southern hemisphere. It lies along the Milky Way. Crux is surrounded by Centarus on three sides.

17. Southern Cross or Crux This constellation once formed the foot of the Centaur. The Cross was part of Centaurus until the 16th century. Try to locate the constellation of Crux in this picture. (Hint: Gamma Crux, at the top of the cross is reddish orange.)

18. Southern Cross or Crux Crux is a circumpolar constellation, which means it never sets... just like our Big Bear (Ursa major). Circumpolar...means it can be seen “year round!” Although it is the most familiar, it is tiny!

19. Inside the Southern Cross Acrux alpha Crucis Acrux is at the foot of the Southern Cross. It is a “blue-white” sub-giant star, located about 200 ly away, and is about 100x brighter than our Sun.

20. Inside the Southern Cross Acrux alpha Crucis Just as Alberio is located at the foot of the Northern Cross, and is a binary, Acrux is at the foot of the Southern Cross. and is also a “binary.” Acrux, is not only the Cross's brightest star but is the 12th brightest star in the sky. It also the southernmost 1st magnitude star.

21. Inside the Southern Cross Mimosa beta Crux Mimosa Mimosa is also a binary of purple-white stars. It is a very hot Class B Giant, 350 LY away.

22. Inside the Southern Cross epsilon Crux New Zealand’s Flag Omits the 5th star Australian National Flag Epsilon Crux is not considered a major part of the asterism of the Southern Cross, yet it is part of the Southern Cross on several national flags. This star is an orange giant, located about 228 ly from Earth.

23. Beware! There is a “False Cross” in Vela, “The Sails” The False Cross has four stars and are not as bright as those of the Southern Cross. But it is larger and better shaped than the Southern Cross. Because of this it was often mistaken by ships' navigators. There are 3 ways of telling the false cross from the true one: 1. The true cross has an extra star on one side, which is absent in the false one. 2. At the feet of the true cross there are four fainter but fairly visible stars. The constellation of the Fly. 3. The true cross has the 2 bright pointers stars: Alpha and Beta Centauri.

24. The Jewel Box Open Star cluster NGC 4755 The "Jewel Box" is a beautiful open star cluster of 100 red, white, and blue stars about 7,600 Light Years away.

25. The Jewel Box Open Star cluster The Jewel Box can be seen with the unaided eye just below Mimosa. It will look like a fuzzy patch. Use binoculars, and it is a beautiful sight!

26. Jewel Box Open Cluster What is this?

27. Coalsack Nebula Dark nebulae are massive clouds of interstellar gases and dust, dense enough to block out most of the light from stars behind it. When you look at this area of sky, you will not see any stars.

28. Coalsack Nebula Of all dark nebulae, the Coal Sack is the largest one visible to the unaided eye. It is enormous and is about 600 ly away. The Coal Sack Nebula and the Horsehead Nebula are the two best known dark nebulae.

29. Ferdinand Magellan Navigated by the skies 1480 to 1521 Ferdinand Magellan studied astronomy and navigation for 2 years before he began his famous voyage. He became the first to sail around the world. Two galaxies bare his name today....

30. Large Magellanic Cloud and the Small Magellanic Cloud Galaxies are classified by their shape. There are 4 shapes. These two galaxies are both irregular galaxies. They are special because they are easy to see with just your eyes.

31. Australiannatives called these “brolgas.” A member of the crane family Yes, the natives had different names, not just for these 2 galaxies, but all the constellations. Many of them were birds! However, when Europeans sailed south, they did not consult the Natives to learn what they were called. They gave them new names and returned home to Europe where they were written on charts.

32. Large Magellanic Cloud and the Small Magellanic Cloud We used to think of these as satellite galaxies, but with new technologies we have learned that they are coming at us very fast, with higher speeds than normal.

33. Large Magellanic Cloud and the Small Magellanic Cloud They are possibly on a “first pass” around us, caught by the gravity of our Milky Way galaxy. We don’t know why, but they are leaving behind a stream of hydrogen gas like the exhaust behind a spaceship!

34. Large Magellanic Cloud (LMC) In the constellation Dorado The Large Magellanic Cloud is 160,000 ly away

35. Inside the LMC 1987 A Supernova Composite of Hubble images over several years In 1987 a bright massive star ran out of fuel and exploded in a spectacular supernova that was seen on Earth. We can still see unusual rings and glowing gas. These rings are excited by light from the initial explosion.

36. Small Magellanic Cloud (SMC) In the constellation of Tucana The bluish hue of the SMC indicates many new, hot, young stars. It is 210,000 ly away. It one of the most distant objects you can see with your eyes.

37. Inside the SMC 47 Toucanae (Pronounced Too-KAY-nay) SMC This is the second brightest globular cluster of the entire sky! 47 Toucanae cluster is a very compact globular cluster. Located just to the north of the SMC.

38. Inside the SMC 47 Toucanae (Pronounced Too-KAY-nay) 47 Toucanae is so compact it looks like a single star! In fact “47 Toucanae” is a star name. You can see this with a small telescope.

40. The Argo Navis XXXXXXXX XXXXXXXX XXXXXXXX In Greek mythology, the Argo Navis Ship was built for Jason and the Argonauts in their search for the Golden Fleece. But it was a huge constellation!

43. The Argo It was so enormous that in 1877 it was divided into 3 parts of a sailing ship: Carina, the Keel Vela, the Sails and Puppis, the Stern

44. Sirius, The Dog Star in Canis Major xxxxx Sirius is the brightest star in the sky, It is the heart of the Big Dog, Canis Major. But what is the name of the 2nd brightest star?

45. Inside Carina (Pronounced Ka-REE-nee) Canopus Canopus is the 2nd brightest star in the night sky. It is 310 ly from Earth.

46. Inside Carinae The Great Nebula in Carinae (Odd things happen here) This nebula is enormous! It is 7x the size of the Orion Nebula. It has the most massive stars known and has also changed its appearance. The Carina Nebula is over 300 ly wide and is about 7000 ly away.

47. Inside the Great Carinae Nebula The Homunculus Nebula (Pronounced Ho-MUN-cu-lus) Inside the Homunculus is Eta Carinae Eta Carinae 100 to 150x mass of our Sun Bright! Massive! The Homunculus Nebula is 3x the size of the Orion Nebula. Eta Carina is the most energetic star in this nebula and was one of the brightest stars in the sky in the 1830s. Then it faded. It has flared in brightness over just the past decade.

48. One day, Eta Carina may Violently explode in a dramatic supernova. Eta Carinae is the only star currently thought to emit natural laser light!

49. Vela, the Sails Vela lies in a part of the Milky Way known as the Gum Nebula. Near the centre of the gigantic Gum Nebula lies the Vela Supernova remnant.

50. We Listen with Radio Telescopes Largest Single Dish Radio Scope Arecibo, Puerto Rico The "dish" is 1000’ in diameter and 167’ deep and covers an area of about 20 acres.