Galaxies & Cosmology winter
trimester
2010-2011
syllabus
& course
expectations
safety,
tardy, classroom computer use, and honesty
Universe/publisher link: register as a student to use the resources
Astronomy
Picture of the Day
the
latest astrophysics discoveries
what's up in the sky
this week
| Monday, October 25 |
Tuesday, October 26 |
October 27 |
October 28 |
October 29 |
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the
stellar birth chapter is supposedly organized into 4 sections: the interstellar matter (raw materials for birth) the trigger (what starts the process) the protostar phase (the free-fall collapse) the pre-main-sequence phase (the slow contraction to the main sequence) |
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(always done before class) |
the interstellar matter (raw materials for birth): 18(1-2) |
the trigger (what starts the process): 18(7-8) |
the protostar
phase (the free-fall collapse): 18(3-5) stars or brown dwarfs or planets? |
the
pre-main-sequence phase (the slow contraction to the main sequence) 18(5-6) |
brown
dwarfs and (extrasolar) planets white book: pp. 31-32 |
questions you should know the answer to before coming to class |
what are the different types of nebulae out in the interstellar space? how does each fit into the scheme of stellar evolution? |
what are the two ways in which an interstellar cloud of gas and dust can begin the process toward starhood? |
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homework (written assignments to be turned in) |
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shockwaves
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 the Antennae, a galaxy-galaxy collision molecular clouds & cooling molecules in space |
the first observations of jets and
disks during stellar
birth Stellar
Disks Set Stage for
disks without
jets: planet
building?:
Protoplanetary Disks |
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of the week |
| Monday, October 18 |
Tuesday, October 19 |
October 20 |
October 21 |
October 22 |
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jit
due today by 8 am and is now available in moodle |
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(always done before class) |
Walker 15(3) on what determines the pressure in a fluid + Walker 16(6) on conduction, convection, and radiation convection is everywhere (and especially see the pictures & captions): all readings in the following from Universe convection in the kitchen and in a greenhouse (pp 212-213) convection in the earth's core (pp 214-215) convection in the earth's mantle (pp 218-219) convection in the earth's atmosphere (pp 224-225) |
neutrinos: 18(4) pp. 407 - 408 & the atmospheric-neutrino article |
still
waiting: how do astronomers KNOW, from observations, that O stars last less long the on the main sequence than B's, which last less long than A's, which last less long than .... ???? it's time for answers!! what type of astronomical object do we need to look at to tell? back to convection.... how many ways does energy get out of the sun? are there any ways it doesn't? have you ever put a pan of water on the stove and watched the water convect? |
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questions you should know the answer to before coming to class |
all those questions from wednesday and friday |
how do astronomers KNOW from observations that O stars last less long on the main sequence than M stars? |
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homework (written assignments to be turned in) |
"YOUR
fusion" reaction assignment due sign up for YOUR reaction (any one on either of the two sheets on the bulletin board OUTSIDE the physics hallway) (just around the corner from the elevator) [the sign-up sheet is page 11 in your green book; follow exactly the procedure i showed you in class! 1) name & show how the three integer conservation laws are obeyed 2) calculate the KE/light released (or absorbed?) in Mev in the nuclear reaction, following the same steps we did in class (make sure you distinguish between atom and nucleus as i did in class on monday) 3) calculate the efficiency of the reaction 4) calculate how long the sun could last in years if it were using this reaction, under the assumptions that a) the original sun was a composition throughout that exactly matched your raw materials in the correct abundance proportions b) the sun's luminosity is constant during the burning and equal to its present value c) the entire star participates entirely in your reaction (and that is the only reaction that the star does) if any of your nuclei are not in Appendix F in Walker, find the mass (in u) here (type your isotope, for example C-12, in the box at the upper left) start EARLY, so that if you end with questions, you can come get help! |
bring
a circle cutout (on colored paper) that reflects your planet's properties and environment: 1) the color of your paper will depend on YOUR PLANET'S TEMPERATURE: BLUE if T < 150 K GREEN: 150 K < T < 250 K YELLOW: 250 K < T < 350 K WHITE: 350 K < T < 650 K ORANGE: 650 K < T < 1000 K RED: T > 1000 K 2) the size of the cutout will depend on YOUR PLANET'S MASS: 1-INCH diameter = 1 Jupiter mass 2-INCH diameter = 2 Jupiter mass etc 3) KNOW the semimajor axis of your star's orbit (i.e., write it on your cut-out), so that you can put it on the board at the right place 4) on your cutout, write a) the SPECTRAL and LUMINOSITY CLASS OF YOUR PLANET'S STAR on the front b) the MASS of your planet in JUPITER UNITS on the back & the median TEMPERATURE of YOUR PLANET on the back C O L O R E D card stock MAY BE in the black box if I find any, but you will likely be more resourceful than I |
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the first neutrino image
of the sun Super-Kamiokande and its photomultipliers surrounding the water (before it was destroyed in a chain reaction) Sudbury Neutrino Observatory detection physics the Mystery of the Missing Neutrinos -- this experiment won half of the 2002 Nobel Prize in Physics |
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cepheid
lab from last monday is due today |
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of the week |
Oldest galaxy found? |
| Monday, October 11 |
Tuesday, October 12 |
October 13 |
October 14 |
October 15 |
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bring
computers for cepheid
lab if you have SalsaJ installed |
jit
due in moodle by midnight yesterday |
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(always done before class) |
16(1,2) on nuclear fusion in the sun |
16(2)
on hydrostatic equilibrium and the physics that runs the inside of the sun Walker 17(2) on the derivation of the perfect gas law, the maxwell-boltzmann distribution, and the how internal energy depends on temperature |
same
reading as yesterday |
32(1
and 8) of Walker on all things nuclear, but see homework box below for
a short bring-to-class assignment that you should do BEFORE reading! mid p. 1022 of Walker to top of p. 126 Universe box 19-2 |
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questions you should know the answer to before coming to class |
how did the temperature
get to be so high at the center of the sun so that fusion could start? why doesn't the sun collapse under its own gravity? why does the gas pressure increase with depth in the sun? why does the gas temperature increase with depth in the sun? what physics law is the perfect gas law in disguise? what is the real version of the perfect gas law? |
same questions as yesterday block D: find the power in the mass-luminosity relation |
we have answered only question (1 and 8), i think, from the wednesday list [and (6) but only in block D] new questions: how do astronomers KNOW, from observations, that O stars spend much less time on the main sequence than M stars, even though we have seen no star leave the main sequence? why is the range of the strong force only 10-15 m? |
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homework (written assignments to be turned in) |
bring to class: a nicely labeled WRITTEN (not mental) table with 4 columns, one for each of the basic forces: gravity, electric, strong nuclear, weak nuclear... the rows are (1) who participates in the force (who/what causes the force or who/what is affected by it) (2) the range of the force (3) the strength of the force (relative to another force) 4) the "direction" of the force (attractive or repulsive) you surely can quickly fill in the 4 rows for both gravity and the electric force (5 - 10 minutes), and you should be looking for the answers for the strong nuclear force as you do your Walker reading extrasolar planet homework due by 5 pm |
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cepheid lab | RW Mon lab due | |||
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of the week |
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Friday, October 8 |
Saturday, October 9 |
October 10 |
weekend reading in order to become more culturally literate.... |
are periodic extinctions really caused by a stellar companion to the sun? A Scientific American debate A UC-Berkeley discussion |
The Universe's Dark Hand, Scientific American, February 2007 dark energy does more than just accelerate the universe's expansion.... |
The Hunt for Dark Matter, Physics World how we might find the neutralino or the axion... and why they might be necessary... requires free sign-up with Physics World (but then who would not want to sign up with something named Physics World?) |
| Monday, October 4 |
Tuesday, October 5 |
October 6 |
October 7 |
October 8 |
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bring
to class: your extrasolar planet's star's radial velocity curve your RW Mon lab book |
not |
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(always done before class) |
check out the eclipsing binary applet |
23(4) & Box 23-2 how to calculate the mass of our galaxy likely observing session tonight, if clear |
23(4)
again.... see new questions below |
24(8) also, read the macrolensing links below block D: be able to explain the 4 rows in the macrolensing effect table both blocks: be able to explain what's going on in the bullet cluster and why the observations are evidence for dark matter |
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questions you should know the answer to before coming to class |
three questions: 1) which star (A or B) is eclipsed at t = 0? (yes, you were supposed to have answered this on last week's jit) 2) how can astronomers tell (from observations) which star (large or small) is eclipsed at t = 0? 3) what star is ALWAYS eclipsed at the deeper eclipse (no matter what)? the more luminous? the less luminous? the larger? the smaller? the hotter? the cooler? the more massive? the less massive? only one answer above is always correct! an explanation is needed, of course! (BIG hint: in which of the two eclipses -- primary (deeper) or secondary (less deep) is more area covered?) you will NOT be able to figure out the answers to (2) and (3) easily UNLESS you cut out some star circles (large and small) and use them! do you understand why the answers to the three questions are important? it's the only way that we can tell .................................. |
what
observational evidence is there for dark matter? what meaurable effects does it produce (that we havent talked about it class yet)? |
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homework (written assignments to be turned in) |
the star-radius calculations that i saw during friday's classs were fairly random..... for today, all previous calculations are required PLUS find the standard values of a B9-main-sequence star's mass and radius (from the first page of the white Astrophysics 2010 book).... if your values don't somewhat match, you know there's an error in your calculations! find it! if you didnt get your equations for the large and small star radii approved last thursday during lab, please send me your equations by noon sunday for approval! (i have kept track of which i have seen and which i have not...) |
bring to class tomorrow: 1) a print-out of your extrasolar planet's star's radial velocity curve (see encyclopedias below in web stuff slot) (if you dont find your planet's star's radial velocity curve in 10 minutes of searching, email me) NOTE: YOUR EXTRASOLAR PLANET may have alternate names.... not all catalogs use the same name to find alternate names for your extrasolar planet's star by going here or here to astronomy's universal name resolver 2) expected values for the masses and radii of the B9 main sequence and G9 subgiant stars of RW Mon (in your lab book) optional, but encouraged: from the physics equations we used in class last week (N's version of K's 3rd law, with special units; the center of mass condition, the formula for speed in a circular orbit), show that (mi sin i)3/(mv + mi)2 = P(vv sin i)3/(2π)3 this should take 15 minutes and 5 lines or fewer.... given the 3 physics equations mentioned above, it's just algebra 1 |
on
paper to hand in at the beginning of class: use your assigned distance-from-the-galactic-center and its corresponding orbital speed, calculate the mass of the galaxy (in solar mass units) interior to your distance |
extrasolar planet homework due late next week |
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the eclipsing binary applet |
European catalog of extrasolar planets another extrasolar planet catalog I found that has more direct links to the original data and is organizable (clickable) by different parameters (period, orbit size, mass, etc) by clicking on the column headings at the top of the page Princeton catalog of extrasolar planets (is apparently no longer being updated) |
mass/energy
inventory of the universe typical
MACHO micro-lensing event |
a galaxy Einstein
ring, gravitational
lensing of a galaxy by a galaxy gravitational lensing of a galaxy
by a cluster of galaxies: 1) NGC 2218 2) CL0024+1654 bullet cluster bullet-cluster animation bullet cluster original article dark matter ring discovered in early 2007 Hubble animation |
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ALL of part c (i.e., the part in parentheses) of the binary lab completed |
read about the things we saw tonight at observatory: Jupiter and its moons, identified via the jupiter satellitle finder M31, the Andromeda galaxy.... the light we saw it by tonight was 2 million years old M13, the globular cluster, 13 billion years old, one of the oldest identifiable things in the galaxy M45, the Pleiades, an open cluster, one of the nearest, only 400 c-years away, intermediate in age between M13 and h and X Persei h and X Persei, another open cluster, one of the youngest.... only 100,000 years old Uranus, the blue planet Neptune, another blue planet what we didn't see: comet Hartley 2 |
doppler effect and parallax labs due | ||
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of the week |
| Monday, September 27 |
Tuesday, September 28 |
September 29 |
September 30 |
October 1 |
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jit
due at slightly after midnight monday but a homework is also due at 5 pm, so you should have one completed by yesterday |
white
book and working calculator necessary for lab today |
remember
that we are spending the entire period on lab today |
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(always done before class) |
26(2) this time it's really chapter 26 but also 4(4 and 7) for starting binary stars; know Kepler's laws alas, various versions of the 3rd law (keep track!) are scattered all over including boxes 4-2 and 4-4 |
for the jit: 17(9-10) assuming you have read the chapter 4 stuff (from yesterday) about orbits |
spend
5 - 10 minutes with the spectroscopic
binary applet & know what a, e, i, and omega stand for (and see the questions below) |
i
think 17(11) will be helpful in doing parts of lab today have you kept up with all previous reading, including playing with the spectroscopic binary applet |
no
new reading |
questions you should know the answer to before coming to class |
now that you know the "correct" origin of galaxies' redshifts [from having read 26(2)], be able to answer these questions: a) what is wrong with box 24-2? b) why can't the redshifts be due to recession of galaxies from us? c) what two-dimensional universe shapes will satisfy the no-center, no-principle? |
what is the single most surprising, stunning thing that you have learned about the universe in the 3-4 days that we have been discussing it? is it that .... ? or that ...? or surely that .... ? or maybe .... ? and that's more stunning than ....? i think that there are 10(!) things to pick from... what's YOUR choice? |
collect all the versions of kepler's 3rd law that the book gave you.... or they all the same (but disguised?) or all they different? is there one better version than all the others? why? |
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homework (written assignments to be turned in) |
bring
on paper to class: evaluate 1/H (the upper limit to the age of the universe if gravity is slowing the universe's acceleration) numerically in years if H = 73 km/s/Mpc if in block D, at least one MORE reason why we want the universe to be homogeneous |
homework on spectra & magnitudes yes, alas, you will have to look up the mercury ionization energies on the web since the white book ran out of space |
number the pages in your white book |
in your lab book, you should have calculated both stars' orbit radii and both stars' masses.... and you did use the version of Kepler's 3rd law with god's units |
in your lab book, calculate the stars' orbital radii in the units requested |
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of the week |
at
last?: earth-like planet discovered & the about-to-be-published article for the not-faint-of-heart |
pages for August 2010