What

1. What Is…?

2. What is a Meteor? What is a Star? What is an Open Cluster? What is a Nebula? What is a Comet? What is a Quasar? What is a Black Hole? ? ? ? ?

3. What Is Astronomy? Reflection nebula IC4606 by George Greaney

4. Galaxy M83 in Hydra by George Greaney Astronomy is a science that attempts to understand the make-up and the history of the universe. What is Astronomy?

5. Basically, if its off this planet its a study of some realm of astronomy. As one might imagine that covers an awful lot of subjects, even more than we know right now. A short list of subjects include: • NGC 253, galaxy in Sculptor • by George Greaney

6. Stars • Nebula • Planets • The Sun • Star clusters • Galaxies • Galaxy clusters • Dark matter • Black holes • The Great Andromeda Galaxy • by George Greaney

7. An Astronomer is a Scientist, skilled in Mathematics, Physics, and Astronomy Most Professional Astronomers work for Universities or Government Agencies Galileo Observatory in Italy Source: The Berkeley Cosmology Group

8. What is an Astronomer? Galileo Galilei (1564-1642) A night watchman with a college education?

9. Few astronomers spend much time looking through a telescope. Most operate telescopes from a control room or even from their computer at home via the Internet. Typical astronomers only spend one or two weeks each year observing, and the rest of their research time analyzing their data. Astronomer Serena Kim at work At Cerro Tololo in Chili Source: Applied Theoretical and Computational Physics DivisionLos Alamos National Laboratory

10. What is an Amateur Astronomer? Amateurs and their tools

11. What is an AmateurAstronomer? Although the Term has different meanings for different people, a basic definition would include anyone who looks into the sky, and wants to see or learn more.

12. Tonight You are an Amateur Astronomer

13. What Is a Meteor?

14. A Meteor from the annual Leonid Meteor shower lights the sky A Meteor is a bright streak across the sky, or a “Shooting star” produced when a small piece of comet or asteroid, called a meteoroid, enters the Earth’s atmosphere. Source: The Lowell Observatory

15. What is a Meteoroid? The Giant Asteroid Gaspra A meteoroid is the dust, rock, or debris still in space. It could be a chunk of an asteroid or comet. Source: NASA

16. What is a Meteorite? The Giant Asteroid Gaspra Meteorite Damage, Peekskill, NY A meteorite is a meteor that actually falls to the ground. Most meteors burn up and never make it to the ground. Source: NASA

17. What Is a Comet? Comet Ikeya Zhang Image by Dave DockeryAstronomical Society of Las Cruces

18. A comet is basically a ball of ice and dust • in space. The typical comet is less than • 10 kilometers across. Most of their time • is spent frozen solid in the outer reaches • of our solar system. Comet Hale Bopp Image by Harvard-Smithsonian Center for Astrophysics

19. A comet orbits around the sun, in a wide, elliptical path. When a comet gets within a few million miles of the sun, it begins to melt, leaving a tail of gas and dust that is blown by solar winds Comet Hale Bopp Source: NASA Image by Harvard-Smithsonian Center for Astrophysics

20. What Is a Star? Image of the Sun from Goddard Space Flight Center

21. What is a Star? Our Sun is the closest star. At the simplest, a star is just a ball of gas that has condensed out of interstellar material. The largest part of its lifetime is spent as a main sequence star during which hydrogen is being converted to helium balancing gravitational contraction so that the radius and energy output remain almost constant. Source: The British Astronomical Association

22. Our Sun is a star that has already spent about 5 billion years on the main sequence. Scientist believe our Sun is roughly halfway through it's life. Source: The British Astronomical Association

23. Nearby Stars: Name Distance from Earth Sun 93 million miles (8 light minutes) Proxima Centauri 4.22 Light Years Alpha Centuri A,B 4.39 Light Years Barnards Star 5.94 Light Years Wolf 359 7.8 Light Years Lalande 21185 8.3 Light Years Sirius A,B 8.6 Light Years Image courtesy of Dave DockeryAstronomical Society of Las Cruces Source: The British Astronomical Association

24. Buzz Lightyear - Superhero What is a Light Year?

25. A Light Year is a unit of Distance, not time. It is the distance that light travels in one earth year, which works out to: 5,903,300,000,000 Miles A Light Year is almost six trillion miles long!

26. That’s a long way! But even further Than most folks realize. Compare this to a distant but familiar object, Like Pluto. Pluto is about 5 light HOURS from Earth. Only a small fraction of a light year Pluto, as seen by theHubble Space Telescope

27. What is a Star Cluster? Omega Centauri Image by Dave DockeryAstronomical Society of Las Cruces

28. Star Clusters are collections of a few dozen to many thousands of stars, which are gravitationally bound. The Pleiades, an open cluster Hercules Cluster, a globular cluster Image by Dave Dockery Image by Dirk Langenbach

29. What Is a Nebula? North American Nebula, Image by George Greaney

30. A nebula is a cloud of gas and dust in space. Some nebulas are regions where new stars are being formed, others are the remains of dead or dying stars. Reflection Nebula IC4592/4601 in Scorpius , byGeorge Greaney Source: NASA

31. Types of Nebula: Emission Nebula An Emission Nebula absorbs the light of nearby stars and reaches very high temperatures. Emission nebula are often found in regions of space where new stars are forming. The Orion Nebula Image by Dave DockeryAstronomical Society of Las Cruces Source:NASA

32. Types of Nebula: Reflection Nebula A Reflection Nebula is a cloud of gas and dust which does not create its own light, but instead shines by reflecting the light from nearby stars. The Pleiades Image by Dave DockeryAstronomical Society of Las Cruces Source:NASA

33. Types of Nebula: Planetary Nebula A planetary nebula is created when a star blows off its outer layers into space, forming a nebula In the shape of a ring or bubble The Dumbell Nebula Image by George Greaney Source:NASA

34. Types of Nebula: Absorption Nebula Dark clouds in space are called absorption nebulas or dark nebulas. An absorption nebula is a cloud of gas and dust which blocks light from the regions of space behind it. The Horsehead Nebula Image by George Greaney

35. The term Nebula was first coined in the 19th century by Herschell, a famous astronomer, to distinguish anything in the sky that looked indistinct. Some of his 'nebulae' turned out to be entire galaxies such as the Andromeda “Nebula“. The Andromeda Galaxy Image by Dave DockeryAstronomical Society of Las Cruces

36. What is a Black Hole? Illustration of Cygnus X-1 from the Astronomy Cafe

37. What is a Black Hole? Loosely speaking, a black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull. Source: The Berkeley Cosmology Group

38. What is a Quasar? Images from Hubble Space Telescope

39. What is a Quasar? Quasars are one of the Most mysterious and rare objects in astronomy A quasar is a very, Very bright object at the core of a few highly active galaxies. Quasars are thought to form as matter spins into super massive black hole at the center of these galaxies. Illustration from the Astronomy Cafe