reAstrophysics fall trimester 2005
syllabus & course expectations & course links
Astronomy
Picture of the Day the
latest astrophysics discoveries
what's up in the sky
this week
Skywatcher's
Diary for this month
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November 7 |
November 8 |
November 9 |
November 10 |
November 11 |
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(always done before class) |
an updated version of pp. 33-34 on the green book: know the difference between stars, brown dwarfs, and planets also, see web stuff below: know the types of extrasolar planets and how those planetary systems came to be |
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what's the difference between stars, BDs, and planets? how do we find BDs? why did it take so long? how do they form? like stars? like planets? stellar old age: red giants: 21(3), 22(1-3) what is this electron degeneracy thing? why does the outer envelope of the star leave (as a planetary nebula)? what force pushes it off? what is a red giant's lifetime? (relative to m.s. lifetime?) red giant --> planetary nebula evolution |
(as a planetary nebula)? what force pushes it off? what is a red giant's lifetime? (relative to m.s. lifetime?) red giant --> planetary nebula evolution 22(4): what are the 5 most important properties of white dwarfs? |
| homework |
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interstellar sugar provides clue to origin of life |
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October 31 |
November 1 |
November 2 |
November 3 |
November 4 |
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(always done before class) |
what are the different kind of nebula? which could lead to star formation in the future? which indicate that star formation has recently taken place? |
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the big question that I will ask you (after we take care of looking at the varioius calculations): how does a cloud/nebula not in the process of contracting (which includes the vast majority of clouds in the galaxy) turn into a cloud that is? if you write down the equation for the total energy of the cloud (KE + GE), the TWO answers should be apparent (as they also are if you have done the reading) |
and the green book pages 27-31 what changes occur in the appearance of a protostar as it progresses through its various phases? how do astronomers know how long a protostar spends in various phases? |
(and read the captions!) on thursday and friday web links below |
| homework |
bring
to class, on paper to hand in: a) name of your nebula type b) physical conditions: temperature = ? (Kelvin) mass = ? (solar masses) radius = ? (parsecs) reference page number from text where you got the above numbers c) calculate (1) the kinetic energy of the nebula (in Joules) (2) the gravitational energy of the nebula (ditto) (3) the total energy of the nebula (ditto) (4) conclusion about whether the nebula is expanding or contracting from calculations above Make sure that your calculation is done in SI units Check your units!! |
bring
to class (on paper that you will hand in): 1) yesterday's assignment 2) determination of the free-fall time of the sun by a) first completing the dimensional analysis problem that we started in class yesterday (and finding tff in terms of G,M,and R) b) substituting in the relevant numbers and finding the free fall time in years 3) calculating the gravitational lifetime of the sun (using the physics we did in class yesterday) in years |
final
project suggestions |
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the GMC at the heart Of Orion Dark Bok
Globules in IC 2944 star formation: star formation propagation(grav collapse induced by shock wave from O/B stellar winds) M16 before
hubble shock-wave
triggered starbirth star
death/supernova: Cygnus
loop shock wave spiral shock waves in galaxies: M51 as seen by
Hubble 2005 M83's emission nebulae
and its spiral arms a bow shock near LL Orionis galaxy collisions: the Antennae: visible and infrared and x-ray |
(theory in pictures) the first observations of jets and
disks during stellar
birth Stellar
Disks Set Stage for
disks without
jets: planet
building?:
Orion Nebula
Mosaic and Protoplanetary Disks |
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Glimmer of first stars spied?.... Spitzer Press Release .... others say "not so fast..." astronomers on verge of seeing black hole? |
Andromeda galaxy Mars & Uranus globular cluster M15 Pleiades h and c Persei double cluster open cluster M38 double star Albireo |
astro pages for october2005
astro pages for september2005
astro pages for august 2005