National Science Olympiad

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National Science Olympiad Astronomy C Event
2010 Normal and Starburst Galaxies
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Participant Sign-In Sheet

• Please enter your name, address and email on the
  Participant Sign-In Sheets which have been placed
  on the tables throughout the room.
• NASAS Chandra X-ray Center sponsors the
  lodging, food, transportation, and other expenses
  associated with my role as a presenter, provides
  the materials distributed to participants
  attending my workshop sessions, and my
  participation as an Event Supervisor at the NSO
  Finals each year.
• Chandra may contact you to ask whether the
  instruction and materials provided during this
  workshop have been helpful to you. Your personal
  information is used solely for the purpose stated
  above.
• High numbers of workshop attendees are an
  important factor to my continued support from
  NASAs Chandra X-ray Center.

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DESCRIPTION

• Students will demonstrate an understanding of the
  basic concepts of mathematics and physics
  relating to galaxies.
• A TEAM OF UP TO 2
• APPROXIMATE TIME 50 Minutes

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EVENT PARAMETERS

• Each team member is permitted to bring a
  programmable calculator and either a laptop
  computer or one 3-ring binder (any size)
  containing information in any form from any
  source. The materials must be 3-hole punched and
  inserted into the rings (notebook sleeves are
  allowable). No internet access allowed.

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THE COMPETITION

• Using information which may include H-R diagrams,
  spectra, light curves, motions, distance
  equations and relationships, stellar magnitudes
  and classification, multi-wavelength images,
  charts, graphs and animations, participants will
  be asked to complete activities for the following
  topics

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THE COMPETITION

• a. Using all available information to determine
  answers relating to normal galaxies definition
  
• Large gravitationally bound systems consisting
  of hundreds of billions of stars, enough gas and
  dust to make billions more stars, and dark matter.

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THE COMPETITION

• a. Using all available information to determine
  answers relating to starburst galaxies
  definition
• Galaxy in which a violent event, such as
  near-collision, has caused a sudden, intense
  burst of star formation in the recent past.

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THE COMPETITION, Subtopic a

• Additional information about starburst galaxies
• Although this activity may last for ten million
  years or more, that is like a month in the life
  of a ten billion year old galaxy.
• During a starburst, stars can form at tens, even
  hundreds of times greater rates than the star
  formation rate in normal galaxies.
• Many of these newly formed stars are very massive
  and very bright, so starburst galaxies are among
  the most luminous galaxies.

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Special Astronomy IssueAn outstanding resource
for the most recent discoveries in Galaxies

• http//www.kalmbachstore.com/scale-modeling-specia
  l-interests-astronomy-special-issues-astronomy-mag
  azine-special-issues.html
• This 108-page special issue from the editors of
  Astronomy magazine features fascinating stories,
  discoveries, insight, and more about the Milky
  Way. New from the editors of Astronomy magazine,
  The Milky Way Inside Out features everything
  you want to know about our galaxy with stories
  such as What is the Milky Way made of?
  Recipe for a galaxy Distant planets The
  search for Earth-like worlds Inside the Orion
  nebula Milkomeda Our galaxys date with
  destruction

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Cosmologys GREATESTDiscoveries

• Special Astronomy IssueProvides information to
  expand knowledge of galaxies. Displayed through
  January, 2010 at speciality newsstands.
• http//www.kalmbachstore.com/scale-modeling-specia
  l-interests-astronomy-special-issues-astronomy-mag
  azine-special-issues.html

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What is a Galaxy?

• Think of a galaxy as a self-gravitating assembly
  of dark matter, stars and gas whose function is
  to convert gas into new suns.

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Introduction to GalaxiesComposition of the
Milky Way

• 1. 10 stars
• 2. 1 interstellar medium, i.e. gas and dust
  drifting between the stars. This 1 has enormous
  potential for star birth. The galaxys gas could
  make enough stars to equal about 1 billion times
  the Suns mass.
• 3. The remaining mass, approximately 89, is
  dark matter which betrays its presence only by
  its gravitational pull on its surroundings. (Dark
  matter matter that neither emits nor reflects
  enough radiation to be detected.)

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Introduction to GalaxiesEvolution of Galaxies

• 1. Galaxies do not evolve in isolation after
  they form
• 2. Galaxies interact with their environments,
  and this shapes their fates.
• a. The Milky Ways gravitational field distorts
  neighboring dwarf galaxies by
  s-t-r-e-t-c-h-i-n-g them across the sky and
  finally absorbing the remains.
• b. Intergalactic clouds, typically containing a
  few million solar masses of hydrogen, may
  interact with and become a part of the galaxy.

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Introduction to Galaxies Galactic Laws

• 1. The galaxy is trying to collapse to a central
  point.
• a. Star formation opposes gravity thus
  preventing collapse.
• b. The Milky Way opposes gravity thus
  preventing collapse.

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Introduction to Galaxies Galactic Laws

• 2. Galactic evolution increases the total
  disorder of the universe.
• a. The term entropy describes the amount of
  randomness or disorder in a self-contained
  system.
• b. The second Galactic law states that physical
  systems tend to move irreversibly toward a state
  of disorder, or increased entropy.
• c. Most of the interstellar pressure
  (preventing collapse of a galaxy) comes from
  turbulent gas motions, cosmic rays and magnetic
  fields generated by the energy input from stars.

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Introduction to Galaxies Galactic Laws

• 3. A galaxys angular momentum must always be
  conserved.
• a. Angular momentum is the tendency of a
  rotating mass to continue doing so unless some
  outside force intervenes.
• b. Because the Milky Ways disk was born
  spinning, it continues to spin.
• c. A cloud of interstellar gas can move toward
  the galaxys center only by shedding some
  angular momentum.

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Introduction to Galaxies Galactic Laws

• 3. A galaxys angular momentum must always be
  conserved. (continued)
• d. The Milky Way and other spiral galaxies have
  two prominent features that allow gas to lose
  angular momentum and migrate toward the center
  bars and spiral arms.

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Introduction to Galaxies Galactic Laws

• 4. Galaxies try to remain symmetrical, but
  usually fail.
• a. The rotating disks of galaxies should be
  symmetric around the rotation axis, but the best
  many can do is to remain bisymmetrical.
• b. Irregularities in galactic shapes may be (1)
  the effect of gravitational interactions with
  neighboring dwarf galaxies, (2) infalling
  intergalactic gas, or (3) the galaxys dark
  matter halo.

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Introduction to GalaxiesEvolution of Galaxies

• 1. Galaxies do not evolve in isolation after
  they form.
• 2. Galaxies interact with their environments,
  and this shapes they fates.
• a. Milky Ways gravitational field distorts
  neighboring dwarf galaxies by stretching them
  across the sky and finally absorbing the
  remains.
• b. Intergalactic clouds typically containing a
  few million solar masses of hydrogen may
  interact with and become part of our galaxy.

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Introduction to GalaxiesEvolution of Galaxies

• 3. Astronomers have located at least two dozen
  large clouds of interstellar gases and hundreds
  of smaller ones orbiting our galaxy.
• 4. Many of these intergalactic clouds serve to
  refuel the galaxys star formation engine.
• 5. Collisions between the Milky Way and dwarf
  galaxies or gas clouds can trigger bursts of star
  formation on their own.

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Introduction to GalaxiesFormation of Bars

• The trigger mechanism for bar formation is not
  clear.
• Stars within the galaxys interior interact with
  each other so that their circular orbits become
  more stretched out, or elliptical.
• These stars then perturb other stars, which
  further rein-forces the bar structure.
• The Milky Way has a prominent galactic bar
  approxi-mately 28,000 light years in length.

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Introduction to GalaxiesFormation of Spiral Arms

• The details of how spiral arms form and propagate
  are still unsettled, but their basic features are
  now fairly clear.
• Spiral arms are actually zones within the
  galactic disk where star density is higher.
• The zones do not rotate along with the disk.
  Instead, stars and gas pass through the zone as
  they orbit the galactic center.
• 4. As stars and gas clouds hit the region of high
  density, they begin to slow down and bunch up. As
  the stars and gas exit the snarl, they spread out
  and resume normal speed.

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Introduction to GalaxiesFormation of Spiral Arms

• During the slowdown, gas passing through the arms
  has a tendency to deflect slightly inward.
• The net effect is for gas to flow toward the
  galactic center.
• 7. This feeds the most active star-forming
  regions.

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Introduction to GalaxiesOvercoming the Dust
Barrier

• In the past, dust in space, although very low in
  density, presented a visual barrier to an
  understanding of galactic star distribution.
• 2. This barrier was brought down by the launching
  of infrared satellites into space.

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Introduction to GalaxiesOvercoming the Dust
Barrier

• The Diffuse Infrared Background Experiment
  aboard the Cosmic Back-ground Explorer (COBE),
  launched in 1998, could not resolve individual
  stars. However, several groups analyzed the light
  distribution and found evidence for a central bar
  in our galaxy.

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Introduction to GalaxiesOvercoming the Dust
Barrier

• The infrared-sensitive Spitzer Telescope,
  launched in 2003, verified the Milky Ways barred
  spiral structure.

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Introduction to GalaxiesOvercoming the Dust
Barrier
Further studies by GLIMPSE Galactic Legacy
Infrared Mid-Plane Survey Extraordinaire found
that the number of stars increase all the way to
the galactic center.
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Galactic Cannibalism

• New theory on large galaxy formation
• Large galaxies, including the Milky Way and
  Andromeda galaxies, grow larger by swallowing
  up dwarf galaxies.
• 2. Clusters orbiting the galactic center
  backward opposite to the Sun and most other
  stars are among the most likely interlopers.
• 3. A massive galaxy exerts powerful tidal forces
  because the gravitational pull acting on the near
  side of a neighbor significantly exceeds that
  acting on the far side.

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Galactic Cannibalism

• New theory on large galaxy formation
• These forces overwhelm the gravity binding a
  dwarf galaxy together and rip it apart.
• The tides draw gas and stars into long trails or
  streams that eventually disperse.
• Once the loot mixes in with the big galaxys
  contents, tracing its origin proves far from
  easy.
• 7. Whether the Large and Small Magellanic Clouds
  are being affected in the manner described above
  is still under study.

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Globular Clusters

• At least 158 dense balls of stars called globular
  clusters orbit within the Milky Ways extended
  galactic halo.
• 2. The majority of these globular clusters might
  be relics of accretion events.
• 3. Clusters, both globular and open, are
  important because the provide a sample of stars
  at the same age, with about the same chemical
  content, and at the same distance from Earth
  which makes them useful for testing theories of
  stellar evolution.

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Star Birth

• When Hubble examined galaxies under-going
  starbursts, it revealed massive, dense, young
  star clusters. These clusters had sizes and
  inferred masses similar to those of intense
  starburst activity. Therefore, galactic
  collisions may lead to the birth not just of new
  stars, but also of new globular clusters.

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Star Clusters

• This is an image of the Antennae galaxies (NGC
  4038/4039) in collision. The collision of these
  two galaxies are locations of intense star
  formation.

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Young Globular Clusters

• The collision triggers the birth of new stars in
  brilliant blue star clusters, the brightest of
  which contains roughly a million stars. The star
  clusters are blue because they are very young,
  the youngest being only a few million years old.
  Not all globular clus-ters are 12 BYO as has been
  thought for years.

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Star Birth

• Gas in starbursts is observed to have high
  pressure, abut 100 to 1000 times higher than
  typical pressures in spiral galaxies. The high
  pressure compresses the gas to the density
  necessary to form stars.
• This explains why star formation in the disk of
  our galaxy no longer produces globulars. The
  pressure has dropped too low.

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Star Birth in Dwarf Galaxies

• Starbursts are not the only way to generate high
  pressures. An alternative mechanism is that star
  formation early in the history of the universe
  heated gas clouds in dwarf and spiral galaxies,
  thereby boosting pressures.
• This may explain why dwarf galaxies and spirals
  contain globular clusters even though they have
  not undergone massive mergers.

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Size of Globular Clusters

• One of the most surprising discoveries in recent
  globular cluster observations is that the size of
  a recently formed globular cluster appears to be
  unrelated to its mass. That is, the more massive
  clusters are not any larger they are just
  denser.

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Normal vs. Starburst Galaxies

• There is not always a clear distinction between
  normal and starburst galaxies. Star formation
  takes place in both usually a galaxy is
  classified as a starburst galaxy if some sort of
  event has caused intensified star formation, such
  as gravitational disturbance from a nearby
  galaxy. The classifi-cation of normal and
  starburst is sometimes arbitrary.

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Normal Galaxies (The Local Group) Objects
located within the Milky Way Galaxy

• Globular Cluster M15

• Galactic Black Hole Sag A

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Normal Galaxies (The Local Group) Object
located within the Milky Way Galaxy
Epsilon Aurigae an eclipsing binary
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Normal Galaxies (The Local Group)
Andromeda Galaxy
Globular Cluster G1 In Andromeda Galaxy
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Normal Galaxies (The Local Group) The Triangulum
Galaxy (M33)
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Normal Galaxies (The Local Group) Objects
located in the Triangulum Galaxy (M33)

• Stellar Nursery NGC 604

• X-Ray Binary M33 X-7

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Starburst Galaxies (Starburst/Normal)

• M82 (The Cigar Galaxy, in the M81 Group) is a
  starburst galaxy with a very active center
  containing star clusters far brighter than any in
  our own Milky Way Galaxy.

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Starburst Galaxies (Starburst/Normal)

• M101 (Pinwheel Galaxy, NGC 5457, in Ursa Major)
  has several extremely bright star-forming (called
  HII regions) regions spread across its spiral
  arms. M101 is so large that its immense gravity
  distorts smaller nearby galaxies.

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Starburst Galaxies (Starburst/Normal)

• Radio observations and images of the Hubble
  Space Telescope of M84 (in the Virgo Cluster)
  have revealed two jets of matter shooting out
  from the galaxy's center as well as a disk of
  rapidly rotating gas and stars close to the
  nucleus indicating the presence of a supermassive
  black hole in the galaxy's nucleus. This is a
  composite image (X-ray, optical and radio).

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Starburst Galaxies (Starburst/Normal)

• The Cartwheel Galaxy (ESO 350-40, in Sculptor
  Cluster) a rare and spectacular head-oncollision
  between two galaxies located 500 million
  light-years away in the constellation Sculptor.

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Starburst Galaxies (Starburst/Normal)

• The Cartwheel Galaxys ring-like shape is the
  result of the gravitational disruption caused by
  a small intruder galaxy passing through a large
  one, compressing the interstellar gas and dust
  and causing a star formation wave to move out
  from the impact point like a ripple across the
  surface of a pond.

Kirk Borne (STScI/NASA
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Starburst Galaxies (Starburst/Normal)
C153 (in Abell 2125 Cluster)
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Starburst Galaxies (Starburst/Normal)

• A comet-like tail of glow-ing gas, 200,000
  light-years long, streams from galaxy C153 as it
  plunges through galaxy cluster Abell 2125 at
  nearly 8 million kilometers per hour.

D.WANG (UMass) et.al. CXC, NASA
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Supernovas

• SN1994D (in NGC 4526), a Type Ia Supernova, is
  the bright spot in the lower left of the
  image.Since all Type Ia supernovae have the same
  intrinsic brightness, then the dimmer a
  super-nova appears, the farther away it must be.

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Supernovas

• Type II Supernova
• SN1993J (in M81) The massive star which
  underwent core-collapse to produce SN1993J was
  identified as a non-variable red supergiant star
  in images of the galaxy M81 taken before
  explosion.

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Supernovas

• In this artist's view the red supergiant
  supernova progenitor star (left) is exploding
  after having transferred about 10 solar masses of
  hydrogen gas to the blue companion star (right).
  This interaction process happened over about 250
  years and affected the supernova explosion to
  such an extent that SN 1993J was later known as
  one of the most peculiar supernovae ever seen.

Artist impression of the 1993J Supernova
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A. Normal Galaxies 1) The Milky Way Galaxy
(MWG) a) Globular Cluster M15
b) Galactic Black Hole Sag A
c) Eclipsing Binary Epsilon Aurigae 2) The
Andromeda Galaxy (M31) a) Globular
Cluster G1 3) The Triangulum Galaxy
(M33) a) Stellar Nursery NGC 604
b) X-Ray Binary M33 X-7 B. Starburst
Galaxies (Starburst/Normal) 1) M82 (The
Cigar Galaxy, in the M81 Group) 2) M101
(Pinwheel Galaxy, NGC 5457, in Ursa Major)
3) M84 (in the Virgo Cluster) 4) The
Cartwheel Galaxy (ESO 350-40, in Sculptor
Cluster) 5) C153 (in Abell 2125 Cluster)
C. Supernovas 1) Type Ia SN1994D (in NGC
4526) 2) Type II SN1993J (in M81)
The Local Group
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• Normal Galaxies The Milky Way Galaxy (MWG)
• Multiwavelength Images

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Normal Galaxies The Milky Way Galaxy (MWG)
Multiwavelength Images
Looking at our own Galaxy with different
telescopes and in different energies, we can see
why multiwavelength astronomy is important. Each
of the images in the chart above illustrates our
Milky Way Galaxy at a different wavelength, but
each gives a different perspective on it.
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Spectra One of Astronomys Greatest Tools
One way to classify stars is by their absorption
spectra. Each element absorbs light at
wavelengths specific to that element and its
atomic composition. The result is black lines of
a continuous spectrum. Here are examples of
spectral types, each associated with a specific
star.
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• Normal Galaxies The Milky Way Galaxy (MWG)
• Structure and Location of Objects

Population I Population II Stars
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Population I vs. Population II Stars

• Stars may be classified by their heavy element
  abundance, which correlates with their age and
  the type of galaxy in which they are found.

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Population I Stars

• Population I stars include the sun and tend to be
  luminous, hot and young, concentrated in the
  disks of spiral galaxies. They are particularly
  found in the spiral arms. With the model of heavy
  element formation in supernovae, this suggests
  that the gas from which they formed had been
  seeded with the heavy elements formed from
  previous giant stars.

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Population II Stars

• Population II stars tend to be found in globular
  clusters and the nucleus of a galaxy. They tend
  to be older, less luminous and cooler than
  Population I stars. They have fewer heavy
  elements, either by being older or being in
  regions where no heavy-element producing
  predecessors would be found.
• Astronomers often describe this condition by
  saying that they are "metal poor", and the
  metallicity is used as an indication of age.

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• Normal Galaxies The Milky Way Galaxy (MWG)
• Globular Cluster M15

Double Neutron Star Binary Systems (X-ray)
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• Normal Galaxies The Milky Way Galaxy (MWG)
• Sagittarius A (Sag A)

Chandra Images Animations Massive Star
Formation Black Hole Binary Swarm
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• Normal Galaxies The Milky Way Galaxy (MWG)
• Epsilon Aurigae Eclipsing Binary System
• http//www.citizensky.org/content/
  star-our-project

http//www.aavso.org/vstar/vsots/eps_aur.shtml
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Epsilon Aurigae

• The end of the year is the prime observing season
  for one of the most enigmatic bright variables in
  our sky -- the mysterious eclipsing binary
  epsilon Aurigae. Although epsilon Aurigae has
  been a known binary for over a century, it isn't
  yet known what exactly is eclipsing what! The
  curious light curves of the eclipses have been
  studied in detail, but they're so infrequent that
  new knowledge is slow in coming -- with a period
  of 27.12 years, only three or four occur each
  century.

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Epsilon Aurigae Location
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Epsilon Aurigae Light Curve (ep si lon  Au
ry gee)

• Visual observations of the 1982-1984 eclipse (G.
  Samolyk). The eclipse is flat-bottomed which
  typically indicates a total eclipse, but the
  light from the F star being eclipsed is present
  in the spectrum throughout the event, and the
  secondary object emits very little light of its
  own. It is believed that the eclipsing secondary
  is a disk seen nearly edge-on, and that the F
  star is not fully eclipsed.

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Epsilon Aurigae - Scale
The primary is 300 times the diameter of our Sun!
The secondary orbits almost at the distance of
Neptune from the Sun. Both components are 14-15
solar masses.
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• Normal Galaxies The Andromeda Galaxy (M31)
• Multiwavelength Images

Ultraviolet
Visible
Infrared
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• Normal Galaxies The Andromeda Galaxy (M31)
• Globular Cluster G1

Mid-sized Black Hole 20,000 Solar Masses,
(Hubble)
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• Normal Galaxies The Triangulum Galaxy (M33)
• NOTE Sometimes M33 is still referred to
  as the Pinwheel Galaxy however M101 is commonly
  called the Pinwheel Galaxy
• and M33 is more commonly
  called the Triangulum Galaxy

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• Normal Galaxies The Triangulum Galaxy (M33)
• NGC 604 Stellar Nursery

Optical, Hubble
X-Ray, Chandra
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• Normal Galaxies The Triangulum Galaxy (M33)
• X-Ray Binary M33 X-7

Optical (Gemini)
Largest stellar mass black hole discovered. 16
solar mass black hole orbiting a 70 solar
mass star.
Eclipse of Black Hole by the Companion Star
(Chandra)
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B. Starburst Galaxies M82 (The Cigar Galaxy in
the M81 Group)
A one hundred million year gravitational dance
twelve million light years away results in
disruption and intensified star formation in
both galaxies, especially M82. In a few billion
years only one of these galaxies will remain.
M82
M81
SN1993J
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B. Starburst Galaxies M101 (Pinwheel Galaxy, NGC
5457)
M101 is 22 million light years away in the
direction of Ursa Major. M101 was selected by
NASAs Great Observatories (Chandra, Hubble,
Spitzer) to celebrate IYA the 400th anniversary
of Galileos telescope.
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B. Starburst Galaxies M84
M84 is 55 million light years away in the Virgo
cluster. M84 gives clues as to how galaxy sizes
are limited by the suppression of unlimited star
formation, similar to M33-x7 mechanism which
stops black holes from continuous mass accretion.
Hubble (optical)
M84
Chandra (X-ray) , VLA (radio)
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B. Starburst Galaxies The Cartwheel Galaxy (ESO
350-40)
The Cartwheel Galaxy is 400 million light years
away in the Sculptor cluster. The intense star
formation has been triggered by the passage of a
smaller galaxy through the middle of the
Cartwheel Galaxy. The trail of the suspected
intruder galaxy is shown in the high resolution
radio image of the neutral hydrogen in the image
on the right. The bright areas in the Chandra
image are black holes which have resulted from
the formation of massive stars as a result of the
collision. The ring of star formation is 100,000
light years across.
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B. Starburst Galaxies C153
C153 is 3 billion light years away in the Abell
2125 galaxy cluster. C153 is Moving at 4.5
million MPH through the cluster of galaxies. The
large scale Disturbance has resulted in star
formation being concentrated on one side Of the
galaxy, and the gas and dust from C153 is being
stripped away and trails the galaxy in 200,000
light year long streamers. 100 million years
ago The cluster containing C153 slammed into
another cluster of galaxies. C153 is losing the
gas and dust necessary for star formation, and
eventually will lose its spiral arm structure
entirely.
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C. Supernovas Type Ia SN1994D (in Galaxy NGC
4526)
NGC 4536 is 108 million light years away. SN1994D
is a Type Ia supernova event the thermonuclear
destruction of a white dwarf star in a binary
system, due to the accretion of enough mass to
exceed the Chandrashekhar Limit. Since all white
dwarfs have the same mass and therefore the
absolute magnitude of the event is known, Type Ia
supernova events are used to calculate distances
to galaxies.
Chandrashekhar Limit is 1.4 solar masses.
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C. Supernovas Type II SN1993J (in M81 Galaxy)
SN1993J was a Type II supernova event the core
collapse of a massive star. The progenitor star
was a massive red supergiant and during the 250
years prior to its collapse its massive companion
star accreted 10 solar masses of
material, leaving the remnant deficient in
hydrogen and rich in helium. The companion star
survived the supernova event.
Light Echo
Companion Star
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Black Holes
Stellar Mass
Stellar mass sized black holes result from the
core collapse of massive stars in Type Ii
supernova events. M33 X-7 is a 16 solar mass
black hole the most massive stellar mass
black hole discovered to date. The smallest mass
black hole so far discovered is 3.8 solar masses.
Intermediate black holes are not the result of
the core collapse of a massive star, nor are they
found in the centers of galaxies. They span the
range from The largest stellar mass black holes
to the smallest supermassive black holes. The
black hole found in M15 contains 20,000 solar
masses too large for a stellar mass black hole
and too small for a super- massive black hole.
There are many theories for their formation,
including coalescence.
Intermediate
Supermassive
Supermassive black holes are found at the centers
of galaxies. The black hole in the middle of the
Milky Way Galaxy is Sgr A and contains 3
million solar masses. The range for
supermassive black holes is from a million to
billions of times more massive than the sun.
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Cepheid and RR Lyrae Variable Stars
Period-Luminosity Relationship and The Distance
Modulus
M m -
5log10 (r)
10
Mv 0.75
RR Lyrae Light curve Globular Clusters
Cepheid Light Curve - Galaxies
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Cepheid Instability Strip
RR Lyrae Strip

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Light Curves
Supernovas
RR Lyrae
Cepheids
Typical Eclipsing Binary
X-Ray Binaries M33 X-7

Epsilon Aurigae
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Cosmological Distances
?Cepheids RR Lyrae
The Distance Modulus M m - 5log10 (r)

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?Type Ia Supernovae
Mv -19.5 
The Distance Modulus M m - 5log10 (r)

10
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Cosmological Distances
Variables
Cepheids RR Lyrae
Spectroscopic Parallax
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Basic Equations and Relationships
The Distance Modulus M m - 5log10 (r)

10 Keplers 3rd Law (MA MB) a3

p2 Hubbles Law d
Vr H0 v d
a v 2p a vP Fc mac ac v2
r?2 t t
r 1 pc
206,265 au 3.26 ly 3.08 x 1016m 1
60 arcmin 60 1 60 arcsec 60? Inverse
Square Law L 1/r2 Circumference, Area, Surface
Area, and Volume of a Sphere
REARRANGE ALL EQUATIONS FOR EACH VARIABLE
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BASIC EQUATIONS RELATIONSHIPS

• The distance modulus can be used to determine
  the distance to a star using the equation m - M
  5 log(d/10) where d is in parsecs. Note that if
  d 10 pc then m and M are the same.
• Visit this URL for fully detailed calculation
  instructions
• http//outreach.atnf.csiro.au/education/senior/ast
  rophysics/photometry_magnitude.html

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BASIC EQUATIONS RELATIONSHIPS
a
3
Keplers 3rd Law (M M )
p
2
A
B
Newton developed a general form of what was
called Kepler's Third Law that could apply to any
two objects orbiting a common center of mass.
This is called Newton's Version of Kepler's Third
Law M1 M2 A3 / P2 Visit the URL below for
practice activities. http//www.austincc.edu/jhea
th/Solar/Hand/NVK3L/nvk3l.htm
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Resources for the Astronomy Event

• Past astronomy exams are posted on the Wright
  Center for Science Education
• Use Key Phrase Wright Center and Science
  Olympiad. or go directly to
• http//www.tufts.edu/as/wright_center/products/sci
  _olympiad/sci_olympiad.html

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Resource Materials
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Variable Star Astronomy http//www.aavso.org/educ
ation/vsa/

• UNIT 1 Planets and Stars
• Chapter 1 The Solar System and Beyond
• Chapter 2 The Nature of Stars
• UNIT 2 Introducing the Sky
• Chapter 3 Familiarizing Yourself With the Night
  sky
• Chapter 4 Our Bearings in the Sky
• UNIT 3 Observing Variable Stars
• Chapter 5 Introducing the Hands-On Astrophysics
  Constellations
• Chapter 6 Measuring Variable Stars Visually
• Chapter 7 Observing Variable Stars in the Real
  Sky

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Variable Star Astronomy http//www.aavso.org/educ
ation/vsa/

• UNIT 4 The Message of Light
• Chapter 8 The Nature of Light
• Chapter 9 The Life of a Star
• UNIT 5 Analysis of Variable Stars
• Chapter 10 Statistical Concepts
• Chapter 11 Variable Stars, Light Curves, and
  Variability
• Chapter 12 Variable Stars and Phase Diagrams
• Chapter 13 Variable Stars and O-C Diagrams

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Distance Modulus

• The following website may assist your Astronomy
  team in discovering how to use the distance
  modulus.
• http//outreach.atnf.csiro.au/education/senior/as
  trophysics/photometry_magnitude.html