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, September 24 |
September 25 |
September 26 |
September 27 |
September 28 |
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if you don't
have your green astro book, I will have to send you back to get it,
which means you will be tardy.... make sure that you bring it! |
jit due by
noon |
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(always done before class) |
review
Universe box7-2 and Universe section 19(5) (I think we are done with Walker for the time being... back to Universe) |
Universe
19(5) again, yes, again |
19(3)
on magnitudes AND all those example problems in Box 19-3 19(7) on the H-R diagram |
19(7),
especially if you didnt read it for yesterday 5(9) on the doppler effect |
[26(1-3):
what's a galaxy?] 26(5): what are galaxies doing? start tuesday reading!: 4(4) including box 4-2 [prereading: 4(1-3)] |
things you should know the answer to before coming to class |
why the H lines are strongest 10,000 K stars! |
the 5-column, 6-row table that we did yesterday in class (on the H lines).... complete the same table for HELIUM and for CALCIUM, using their energy level diagram before coming to class, in order to explain when (i.e., at what temperatures) the visible lines of He are strong in stars, .... the uv lines, the ir lines, etc etc IMPORTANT: the lines connecting different levels on the energy-level diagrams in the green book are labeled with the wavelength IN ANGSTROMS (not NANOMETERS) of the light emitted/absorbed in thAT transition |
i
will ask you to review the present state of your knowledge of 1) what quantities can we OBSERVE for stars 2) what quantities can we DEDUCE from the above observed quantities? (in other words, how much progress have we made in the lists we made at the beginning of the year?) from 19(3): what do apparent and absolute magnitudes each measure? what are the two important rules about magnitudes what other scales are like the magnitude scales (in that they are based on equal ratios between steps)? (at least 4 should come to mind) what law is disguised in equation at the top of the first column page 419? from 19(7): which way do L,R, T increase on the HR diagram? |
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homework (written assignments to be turned in) |
homework due by 5:15 pm |
brought
to class the temperature of the sun calculated from the lines present in the flash spectrum (and why is the Fe XIV line the important one?) |
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fluorescence in
the image processing lab: fluorescing hydrogen regions around hot stars in M100 help us trace the spiral arms and places of recent stellar birth these emission nebulae are starbirth nebula: the Lagoon nebula M8 which we saw during theobserving session; note that red- fluorescing nebulas can only surround BLUE (uv-emitting stars)
spectrum
of a planetary
nebula The Crab Nebula
& [these
two supernovas left behind neutron stars (stars made entirely of
neutrons that are about the size of durham)] gas
in the Coma Cluster of galaxies fluorescing things we DIDNT see in the image processing lab: Comet tails both fluoresce and reflect... can you tell which is which? A Perseid Aurora
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doppler
effect applet |
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of the week |
Orphan Stars
Found in Long Galaxy Tail
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North
Carolina Astronomers meet in Greensboro today and tomorrow |
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September 17 |
September 18 |
September 19 |
September 20 |
September 21 |
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(always done before class) |
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chapter 10; see what's there read Walker up through bottom of p. 1043 |
skim chapter 11; read carefully section 11-7 up through the end of active example 11-4 bottom of p. 1043 up through the bottom of p. 1045 |
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things you should know the answer to before coming to class |
bring
to class on paper, susceptible to hand-in: 1) new physics (new laws, new formulas), not accounted in previous physics 2) wrong (or incomplete) physics 3) connections to spectra lab |
what's chapter 10 about? |
what's chapter 11 about? given our formula for angular momentum yesterday in class, how does the angular momentum of our Bohr electron become L = m v r ? there is an energy level diagram for a hydrogen atom in Walker on page 1044 and in Universe on page 112 yet they have different energy numbers on the vertical scale! whose is correct? |
the answers to the JIT questions |
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| homework (written assignments to be turned in) |
bring
to class: ratio of electric force to gravity force (or vice versa) for the proton/electron in the H atom no numbers till end check units |
asteroid parallax due |
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real shoes, long pants, long shirt required; bring sky map for September |
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| Monday, September 10 |
September 11 |
September 12 |
September 13 |
September 14 |
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parents jit
due tomorrow by 9 am |
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(always done before class) |
7(6,7) & 8(3) [it's assumed that you have already read 7(1,4) and 8(1-2,4-5)] |
box
7-2 box 8-1 7(6.7) |
skim
chapters 9, 10, 11 for help (find what looks like a useful section and
then read it) in answering the question below; at least 3 answers have already appeared in the reading assigned from chapters 7-8 |
reading
on the 4 extra sources of energy for planetary heating beyond sunlight radioactivity: p. 170 tides: p. 219 greenhouse effect: p. 248 gravitational energy released during accretion: |
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things you should know the answer to before coming to class |
look
at the list of the 12
differences between terrestrial and jovian planets from last friday's
class which are easy to explain by the condensation-accretion theory? be able to do so |
as you read, be thinking about what energy sources we left out of our planetary calculation yesterday in class |
see below: what sources of planet energy got left out when we did our planet calculations on tuesday |
see above reading and below homework some other questions: how is that planets (such as earth) have their metals at the center and their silicates nearer the surface? how do we know the age of the solar system? |
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homework (written assignments to be turned in) |
calculation of your luminosity make a simple approximation of your surface area... pay attention to significant figures... check your units! |
"your planet" temperature calculation due in class "your star" homework due at 5:30 pm |
bring to class to hand in: 2 (or 3) energy sources that planets might have that account for why their actual temperature turned out to be larger than their blackbody temperature (calculated on the basis of sunlight and refletion only) as we saw in class on tuesday each energy source should be accompanied by a description of how that energy source heats a planet, and/or perhaps for which planets this energy source might be important, when (in solar system history) this source of energy might have been around, etc (it might help to make a list of energies you learned about last year in physics, because that might trigger a match with some energy source in your reading from the astro book) |
since 4 more energy sources are still up for grabs, you are allowed to add ANY HEATING SOURCE NOT YET DISCUSSED (i.e., not the 4 above) to the paper you brought to class yesterday and will turn in today in class (it might also be a good idea to add a page number reference to the text for the energy sources you listed on your homework) |
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lab
books available at 6 pm today you may want to do the prelab for tomorrow (see the box ----->) if you have access to the software |
today's
lab: asteroid parallax we will use the HOU software... it would be a good idea to bring your computer if you have the HOU software installed; otherwise, bring a flash drive to save your intermediate images images are here: asteroid1.fts asteroid2.fts prelab: identify the asteroid in each image (in your lab book, to be returned yesterday) by looking for the object not at the same position in the two images |
last
week's sun lab due TODAY remember that in accounting for why your calculated value of the solar luminosity is too high or too low, you only want the MAJOR reason of each type, not dinky reasons of each type |
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of the week |
| Monday, September 3 |
September 4 |
September 5 |
September 6 |
September 7 |
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students
return |
jit due at
noon |
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(always done before class) |
blue sky, red sky, and more see "web stuff" below |
review
flux and luminosity, particularly the examples 19(2) [yes, we skipped 19(1)] pick your star (from Appendix 5) in class; first come, first choice |
if
it's clear, read a) the lab (see below) up to the "Results" section.... note that you will receive a lab grade at the time you leave the roof (that checks to make sure that you have collected all necessary data and recorded it properly) b) how a pinhole camera works up to the end of othe "invention" section if it's not going to be clear during lab, see tomorrow's assignment ---> including what you should know, below it |
19(1)
assuming it was clear yesterday |
7(1,4) and 8(1,2,4,5) |
things you should know the answer to before coming to class (or answering the JIT) |
how to distinguish between flux and luminosity |
how
astronomers use parallax to measure distance where the formula d = 1/p came from? be ready to present why is the parallax method limited by some maximum distance? what planet (in the solar system) would astronomers like to be living on to measure parallaxes? |
important
differences between terrestrial and jovian planets basic features of the condensation-accretion theory of planetary formation why terrestrials and jovians ended up so different in size/mass and composition |
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homework (written assignments to be turned in) |
have you signed up for a star? |
due
next monday at 8 am for your star: a) identify your star's name & the spectral/luminosity class listed in the Appendix b) determine your star's temperature (in K) c) determine the wavelength of max intensity for your star AND what color your star would appear to humans d) use your star's apparent magnitude (along with the sun's apparent magnitude and sun's known flux) to determine your star's flux e) determine your star's luminosity relative to the sun.... show work! (your luminosity ratio should also match that given in Figure 19-14a) f) the radius of your star (relative to sun) [see box 19-4 and follow the procedure exactly] (your answer should also match that given in Figure 19-14b) g) if we define the sun as fist-sized, what real life object (either bring one or have a classroom object identified) that approximately matches your star's size h) determine what fraction of your star's luminosity is emitted in the uv, in the visible, and in the ir (using the spectrum explorer applet) |
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the dark lunar eclipse of august 28 the complete eclipse, in 4-minute intervals red sky on Mars red sky on Earth (due to volcanic eruptions).... and also responsible for the red sky in Edvard Munch's "The Scream" Rayleigh scattering and blue sky, blue water, and ... relfection nebulas are blue but not due to rayleigh scattering and the blue of blue jays was thought to be due to Rayleigh scattering until 4 years ago when someone checked.... full details from Journal of Experimental Biology |
spectrum
explorer (launch the explorer; it requires java, so that must be enabled; 2 new windows should open in a minute or 2-- a useless one and one containing axes; on the latter, click on the "blackbody" button to add a blackbody, type in the temperature below the thermometer, and you'll find the %s in another new, tiny window that opens |
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pick
up lab book outside of physics floor and prepare book for tomorrow's
lab? |
we
measure the luminosity, radius, and temperature of the sun with a
meter
stick, a light bulb, a cardboard poster tube, wax, and aluminum foil (if it's clear) don't wear nice clothes.... you may have to sit on the grimy roof |
spectra
lab due dont wait till the last minute |
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of the week |
