INTRODUCTION. Lawrence Halstead Cell:

Transcription

1 INTRODUCTION Lawrence Halstead Cell:

2 ASTRONOMY BASICS Planets, stars, galaxies an issue of scale Most celestial objects can be found by locating two roughly flat, circular planes Ecliptic plane (Solar System) Galactic plane (Milky Way) Distances are usually measured in light years 1 light year = distance light travels in 1 year Speed of light = 186,000 miles / second 1 light year = a little less than 6 trillion miles

3 Plane #1 : The Ecliptic Plane

4 The Solar System The Ecliptic Plane

5 THE ECLIPTIC PLANE

6 THE ECLIPTIC saturn PLANE moon mars venus This is where you can see the Sun, the Moon and all the planets sun

7 Views from the Ecliptic Plane Al Bates - FAAC

8 Mercury NASA

9 Venus NASA / JPL

10 The Moon NASA LICK OBSERVATORY

11 Mars (+2 moons) NASA / USGS NASA / JPL

12 Jupiter (+67 moons) NASA / CASSINI

13 Saturn (+62 moons) NASA / JPL / CASSINI / ESA

14 Uranus (+27 moons) ESO NASA/ESA/STSCl

15 Neptune (+14 moons) NASA / JPL NASA / VOYAGER 15

16 Pluto (+5 moons) NASA-JHUAPL-SWRI -

17 Dwarf Planets LEXICON 17

18 Kuiper Belt (out to about.001 LY) WilyD on English Wikipedia ASA/ESA/G. Bacon 18

19 Oort Cloud (out to about 0.7 LY away) w/ User / Mkfairdpm NASA 19

20 The Planets and the Sun Most stars are smaller than the Sun. But most stars that we can see are larger than the Sun.

21 Our Sun to Antares Rigel is 50,000 times more luminous than the Sun.

22 Plane #2: THE MILKY WAY GALAXY (artist s concept, not a photo) 80,000 light years across Sun/Ecliptic

23 The ecliptic plane and the Milky Way galaxy

24 THE MILKY WAY GALAXY as seen from within This is where you can find nebulae and star clusters in abundance Kerry-Ann Lecky Hepburn -

25 THE MILKY WAY GALAXY The big picture

26 Views from the Galactic Plane Kerry-Ann Lecky Hepburn -

27 Beyond Plane #2: Andromeda Galaxy (M31) 2.3 million light years away

28 Views from beyond the Galactic Plane Kerry-Ann Lecky Hepburn -

29 Virgo Galaxy Cluster 60 million light years away

30 As far as we can see (Hubble Deep Field) about 10 billion light years

31 Astronomy Basics Summary Celestial objects appear to rise and set in roughly circular paths. The sun is a larger than average star about halfway out along a small spiral arm of the Milky Way Galaxy. The positions of various celestial objects are predictable. Once you know where to look, it all makes sense. Sun, Moon, and planets in the ecliptic plane. Star clusters and nebulae in the galactic plane. Galaxies above or below the galactic plane. The scales are daunting.

32 A telescope is a light bucket REU program, N.A.Sharp/NOAO/AURA/NSF

33 Different types of scopes REFRACTOR REFLECTOR SCHMIDT-CASSEGRAIN Messer Woland

34 Setting up the rental scopes Finder Main eyepiece Focus knob Do not touch knobs on back of the scope 34

35 Setting up your finder EYEPIECE FINDER FINDER - ADJUST FINDER EYEPIECE Al Bates - FAAC

36 Turn on the red dot finder Look through here to see the red dot. Turn this dial CW (click) to turn on the red dot. Turn it farther to make it brighter. 36

37 Align the red dot finder Turn this knob to move the red dot from side to side Turn this knob to move the red dot up and down 37

38 Tonight s targets: The Moon Jupiter Saturn Mars ISS (10:02 PM for 3 minutes) Albireo Hercules Cluster Ring Nebula 38

39 Why do constellations change during the year? Summer Sagittarius, Scorpius Spring Virgo, Leo Fall Pegasus, Pisces Winter Orion, Gemini

40 CYGNUS THE SWAN FLIES ALONG THE SUMMER MILKY WAY TOWARD THE GALACTIC CENTER.. CYGNUS LYRA HERCULES HERCULES IS A TRAPEZOID LYING 1/3 OF THE WAY FROM VEGA TO ARCTURUS. Summer guideposts looking high toward southeast AQUILA THE SUMMER TRIANGLE OF BRIGHT STARS: DENEB IN CYGNUS, VEGA IN LYRA, ALTAIR IN AQUILA THE CENTER OF THE MILKY WAY GALAXY LOOKS LIKE STEAM RISING FROM THE TEAPOT OF SAGITTARIUS. GALACTIC PLANE SCORPIUS ECLIPTIC PLANE SAGITTARIUS

41 Moon s path Milky Way Horizon Looking Southwest mid-summer to early fall 2016

42 Hercules Star Cluster The Northern Cross Milky Way Albireo: Blue and Gold Double Star Looking southeast high overhead mid-summer to early fall

43 Seeing the ISS Go to NASA Human Space Flight Tracking website: Click sighting opportunities Input your location Find sighting times and directions. Remember that satellites generally fly west to east. Mike Tyrell astrospider.com

44 Neutron Stars Massive star undergoes supernova. Remnants collapse into highly dense core. 1 tsp of material would weigh about 12,000,000,000,000 lbf on Earth. As electron capture occurs, protons become neutrons. As collapse occurs, spin becomes very rapid. May appear to us as a pulsar. NASA/ESA/Hubble

45 Black Holes If the initial star is sufficiently massive, the collapse does not stop at the neutron level. The core collapses to a singularity. Such a severe distortion in space and time that light cannot escape - i.e. escape velocity is greater than c. Space and time effectively face a threshold at the event horizon.

46 Supermassive Black Holes Millions or billions of solar masses Occur at the center of most galaxies. Ingest matter in a disk shape and eject what escapes in polar jets. NASA/JPL/CalTech

47 The Supermassive Black Hole in Our Galaxy

48 Supermassive Black Holes Most are fairly quiet. When they become active, the gas / dust / stars streaming into the hole become very hot and very bright. When they become active, the jets become very hot and very bright. QUIET Kerry-Ann Lecky Hepburn NASA/ESA/Hubble ACTIVE

49 Quasars NASA/ESA/Hubble Originally thought to be very energetic, nearby stars. Found to be beyond way beyond the reaches of our galaxy. This meant that these objects were as bright as entire galaxies, but very small and very far away. More numerous at great distances i.e. very long ago. Now thought to be galaxies in the process of formation, with active black holes gathering mass and producing enormous energy.

50 Gravitational Lensing Extreme gravity around massive objects distorts space and time. This can cause light to bend as it follows the curvature of spacetime. Such a phenomenon can act like a lens. NASA/ESA/Hubble

51 Gravitational Waves Detected in September 2015 at two locations almost simultaneously. These two instruments measured tiny (1/1000 the size of a proton) distortions in spacetime by measuring the stretching of the Earth as the waves pass through it. The results matched Einstein s predictions precisely for the merging of two medium sized black holes at ~ 1/2 c about 1.3 billion years ago. The energy difference between the merging black holes and the final black hole was 3 solar masses!! If gravitons were involved, they were limited to less than 10 e - 55 kg 51

52 Recommended Reading Nightwatch Terence Dickinson (Firefly) Absolutely the best source book for beginners. Astronomy Hacks Robert Bruce Thompson and Barbara Fritchman Thompson (O Reilly) Great tips for observing, describes what is generally learned only by experience. The Universe from your Backyard David J. Eicher (Astromedia) Excellent reference for amateur observers. Death by Black Hole and other Cosmic Quandaries Neil DeGrasse Tyson (Norton) Interesting description of current state of the art. Burnham s Celestial Handbook Volumes 1 3 Robert Burnham Jr. (Dover) In depth reference, includes fascinating details, technical. Bad Astronomy Philip Plait (Wiley) funny and accurate description of astronomy hoaxes and the arguments against them. Cosmos Carl Sagan (Random House) still one of the best books on the subject, slightly outdated.

53 Picture Credits Celestron Robert Nemiroff and JerryBonnell Astronomy Picture of the Day Jerry Lodriguss - Kerry-Ann Lecky Hepburn - Guillaume Dargaud - Mike Tyrell astrospider.com National Optical Astronomy Observatory/Association of Universities for Research in Astronomy/National Science Foundation REU program, N.A.Sharp/NOAO/AURA/NSF NASA, ESO, JPL Messer Woland Creative Commons Attribution Share Alike 2.5 David Snyder - University Low Brow Astronomers Al Bates - Ford Amateur Astronomy Club Greg Burnett Ford Amateur Astronomy Club Paul Walkowski - University Low Brow Astronomers

54 Summer scope targets DENEB 1600 LY M92 GLOBULAR CLUSTER SLIGHTLY SMALLER THAN M13 26 KLY M13 STUNNING GLOBULAR CLUSTER ROUGHLY ½ MILLION STARS IN ONE SPHERICAL GROUP 21KLY CYGNUS VEGA 25 LY LYRA HERCULES THE CYGNUS REGION IS ONE OF THE RICHEST STAR FIELDS IN THE MILKY WAY. THOUSANDS OF STARS CAN BE SEEN IN BINOCULARS ALBIREO BEAUTIFUL BLUE AND GOLD DOUBLE STAR M57 RING NEBULA REMAINS OF A DYING STAR LOOKS LIKE A DONUT 1400 LY

55 More summer scope targets OPHIUCHUS ALTAIR 17 LY AQUILA M11 WILD DUCK CLUSTER 6 KLY M17 SWAN NEBULA BRIGHT 6 KLY M20 TRIFID NEBULA 5 KLY ANTARES RED SUPERGIANT STAR 600 LY M4 GLOBULAR CLUSTER 14 KLY M22 GLOBULAR CLUSTER BRIGHT 10 KLY M8 LAGOON NEBULA BRIGHT 4 KLY SCORPIUS THE REGION SURROUNDING THE MILKY WAY GALACTIC CENTER IS PACKED WITH MILLIONS OF STARS AND HUNDREDS OF STAR CLUSTERS. SAGITTARIUS JEWEL BOX CLUSTER