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Astro Quiz 4
sol sys, formn, moon, comets, sun, atoms, asts, stars, sol mag field
99
Astronomy
Undergraduate 1
10/31/2009

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Term
(3)minor bodies in solar sys
Definition
dwarf plts, comets, asteroids
Term
(4)dwarf plts. 5 ex's
Definition
orbit sun, have sufficient mass, havent cleared nbhd ar orbit, arent sats. pluto, ceres, charon, xena, quaoar
Term
(3)misc. solar sys
Definition
moons, dust, gas
Term
(6)jovian plts, 4 ex's
Definition
sim to jup, gassy, lg, massive, low density, far f sun. jup saturn uranus neptune
Term
(2)mass of plt
Definition
deted by its orbital eccentricity. Es mass= 1.00
Term
(2)density=
Definition
ratio of amt of matter of obj compared to its V. Es dens= 5.52
Term
(4)density m.ed by
Definition
mass (f watching orbits of sats) and V (f m.ing angular sz and d to get r)
Term
(4)common chars of plts
Definition
orbit in same dir, rot in same dir runt themselves (*alm all), orbit in same plane (wi 10deg of ecliptic), have alm circular orbits
Term
(4)def of plt
Definition
cel body t orbits sun, has sufficient mass, nearly round shape, has cleared nbhd runt its orbit. deted by IAU in 06
Term
(2)ceres
Definition
first ast to be disced (1801). was classed as plt
Term
(5)pluto
Definition
disced 1930 as obj, not plt. has sats (moons), atm at perihelion. mass=.2% Es mass. extremely low density - sig portion must be ice
Term
(5)charon
Definition
circular orbit. it and pluto orbit eo. its moon is tidally locked to pluto. mass=10% plutos mass. r= 1/2 plutos r
Term
(7)Plutos orbit
Definition
high eccentric/elliptical. Crosses Neps orbit (as do other kuiper belt objs). Inclined at 17deg. Doesnt orbit in ecliptic plane. Hasnt cleared path of orbit (T, is not plt).
Term
(4)sol nebula hyp
Definition

1. cloud of dust and gas rotated ltly.

2. contracted under G, spun faster.

3. center blev sun, outer disk blev plts.

Expls sys's flat shape and plts rotn runt sun

Term
angular mom=
Definition
m of objs tendency to keep rotating and maintain orientation
Term
(2)angular mom =tions
Definition

J= m(mass) * v(rotl v) * r(sz)

 

J= l(rotl inertia) * w(angular v)

Term
(2)interstellar cloud=
Definition
enormous rotating aggregate of cloud and dust. all stars formed f them
Term
(3)our sol nebula cloud
Definition
a few lt yrs in D, contained ab twice suns mass, comp sim to suns atm today
Term
(5)neb clouds flattening
Definition

1. G pulling in + outward push f rotn = bulge

2. cloud rotn rate incs due to angular mom

3. partles spd up, incing gas and dust temp

4. partles collide. lose e in dir

perpendicular to clouds rotn

5. disk flattens

Term
(3)form.n of plts
Definition

1. sm dust grains (interstellar dust) condense into ice/water in outer parts of disk, bc theyre farthest f sun

2. pltesimals form due to accretion

3. inced mass Gly attracts more nebular debris

Term
(3)form.n of jovian plts
Definition
prob not accretion. formed directly f dense gas regions in disk. G allowed capture and retention of atm
Term
(4)What chars of jovian plts are due to their form.n?
Definition
low temp, dense cores, lots of H, massive atm
Term
(2-7)retention of plts atm due lgly to
Definition
its sz (m and r) and d f sun (T, surf temp -> spd of mols -> esc v?)
Term
(2)gas mols move faster for
Definition
lter mols and jovian plts
Term
inner structure of t plts
Definition
mantle of silicate rock, core of iron/nickel
Term
inner structure of j plts
Definition
mantle of gas, core of iron and rock
Term
(2)removing debris
Definition
accretion leaves excess dust. grains smer th .1 um are pushed out sol sys by radn pressure f sun
Term
(2)radn pressure
Definition
very sm pressure exerted on partles by sunlt. picture lt as stream of partles (photons) w mom
Term
(5)infl of radn pressure deps on
Definition
sz, material, shape, and structure of dust grains, and temp of star (sun)
Term
(3)zodiacal lt
Definition
lt reflected f dust partles. shows us dust in sol sys. we see it shortly after sunset and b4 sunrise
Term
(2)sources of dust
Definition
grinding dn of ast.al bodies, evaporation of cometary bodies
Term
accretion=
Definition
tiny partles t condensed f neb stick ihop
Term
Hm sats are there in the sol sys?
Definition
335
Term
(3)sats have orbits
Definition
nearly circ. in same dir as plt spins. close to plane of plts =tor
Term
How were sats formed?
Definition
scaled-dn version of sol neb
Term
(3)our moon m/o
Definition
maria (dark As) + terrae (lt As) + craters
Term
(5)martian moons
Definition
phobos (lger, denser, closer) and deimos. irreg shps, craters. syn rot pds.
Term
(8)main jup moons
Definition
io europa ganymede callisto (lgest, farthest, lowest dens, most inclined)
Term
(3)jup moons
Definition
aka galilean moons/sats. 63 total. syn rot orbits.
Term
(3)Ganymede
Definition
lgest moon in sol sys (lger th mercury). mo rock, water, metallic core. thin o2 atm
Term
(5)titan
Definition
one of 61 saturn moons. syn rot orbit. dense n2 atm. liquid h2 lakes. surf is young
Term
(4)uranus moons
Definition
27 known. miranda ariel umbriel. dark. no atm
Term
(2)triton
Definition
lgest of 13 nep moons. syn rot pd
Term
(3)comet mo
Definition
nucleus, coma (cloud of dust runt n), tails
Term
nucleus=
Definition
core of frozen gases and dust t make up comet's solid part
Term
(3)comet phys chars
Definition
mo rock dust ice water frozen gases. irreg-shped bodies. dark
Term
kuiper belt contains
Definition
objs t orbit sun beyond neps orbit (40 AU)
Term
(4)oort cloud
Definition
hyp.ed spherical cloud of comets t surrounds sol sys, beyond plutos orbit (10-100thou AU). Gases and ices still frozen. No confirmation so far
Term
(6)tail of gas
Definition
ions. blue. infled by sol wind. dired away f sun. lgest part of comet. sm mass
Term
(4)dust tail
Definition
yellow-white. infled by radn pressure. bent towards comets orbit. wide
Term
(4.2)short-pd comets
Definition
orbital pd < 200yrs. orig in kuiper belt. low inclination, close to ecliptic. ex: halley (T=76 yrs, very elliptical orbit)
Term
(3.2)long-pd comets
Definition
orbital pd > 200yrs. orig in oort cloud. ex: hale-bopp (T=2533 yrs, alm perfectly elliptical orbit)
Term
meteor shower=
Definition
E passing thru trail of dust left by comet
Term
Why can you see a comets coma when it comes near the sun?
Definition
surf temp incs, comet blir active. ice under surf hts up, hay explosion on surf
Term
suns comp
Definition
H 92%, He 8%
Term
(3)hydrostatic equilibrium
Definition
G inward + gas pressure outward. P below > P above. Sun will remain same sz as long as it conts prod.ing e at sm rate
Term
(3)suns core
Definition
e prodn (radiated by nr fusion). has temp 15mil K. plasma at center supports entire mass of sun
Term
radiative zone
Definition
e transported by em radn (photons)
Term
(3)convection zone
Definition
e carried by convection. atoms are less completely ionized. e trapped and hts gas
Term
(4)photosphere
Definition
em radn escs -> vis surf. source of absorption sp. low-dens. gas grows denser below and thinner above
Term
(4)chromosphere
Definition
lower atm. coolest part, but temp rises as r incs. can be seen as red ln in complete sol eclipse. source of emission sp
Term
transition zone
Definition
rapid inc in temp in these few 100km
Term
(4)corona
Definition
upper/outer atm. can be seen in vis lt in total sol eclipse. extremely hot gas w low dens. infled by mag field.
Term
(6)suns lvls
Definition
core, radiative zone, convection zone, photosphere, chromosphere, corona
Term
(2)suns atm
Definition
low-dens gases t lie above pho. chr + cor
Term
(2)heliosmology
Definition
analysis of pressure waves on sol srf. only way to view sol interior.
Term
atom mo
Definition
n (pns + nns) and ens in orbit ar n
Term
isotope of el
Definition
has same # pns but diff # nns
Term
AZSymbol
Definition
A= mass # (pns + nns), Z= atomic # (pns)
Term
(2)nr fusion
Definition
process t binds 2 or more atomic n into one heavier one. E=(delta)m*c^2
Term
(2-4)reqs for nr fusion
Definition
high temp (at least 10^7 K), high dens (so t collisions are common)
Term
(3)pn-pn chain
Definition

1. 2 pns (1H n) fuse ihop =>

2H isotope (n of 1 pn+1 nn)

2. 2H n collides w 1H n => 3He isotope

3. 2 3He n fuse => 4He and 2 1H n.

2 pns ejected by elec propulsion

Term
(2)CNO cycle
Definition
converts H to He, using C as catalyst. occurs in higher-temp stars
Term
Hm mass is converted into e every sec?
Definition
4.7 mil tons
Term
(2)kirkwood gap
Definition
seemingly empty region in ast belt. d at wh ast would have orbital pd 1/3 jups
Term
trojans
Definition
asts t orbit jup in 2 stable pts: 60deg b4 and behind it.
Term
(2)differentiation
Definition
dense mat settles to core of obj, leaving lter mat on srf/mantle. temp must be high enuf t mat can melt
Term
meteorites
Definition
fragments of asts collected on Es srf
Term
meteoroids
Definition
sm objs moving in sol sys
Term
(3)heliopause
Definition
pt where sol wind is no longer strong enuf to push back interstellar med. often considered outer boundary of sol sys. d unknown, but lies far outside pluto
Term
bow shock
Definition
d where interstellar wind starts to decelerate into sol wind
Term
(3)sol wind
Definition
ched partles moving away f sun. loses ab 10mil tons mat/yr. confines mag fields.
Term
stellar seq (hot to cold)
Definition
O (blue) A (white) G (yellow) M (red)
Term
ch in absorption lns due to
Definition
ch in temp, not in comp
Term
B and O stars
Definition
have less H lns bc hay less atomic H. He is dom
Term
K stars
Definition
are too hot to form mols
Term
(2)M stars
Definition
are cool enuf to form mols. H lines absent due to lack of excitation e
Term
(2)sol mag field causes
Definition
suns srf and atmic activity
Term
(3)mag dynamo
Definition
1. sun rotates faster at =tor
2. mag field lines wind ar =tor, coils ar sun
3. kinks dev t break thru srf and come back in at sun spots (N and S poles)
Term
What makes the mag field strong?
Definition
plasma (ionized gas) and sol rotn
Term
(4)sun spots
Definition
are cool (4500K). bright. very strong mag field. prevents transport of e
Term
(2)zeeman effect
Definition
sp lns split into sev lns in presence of strong mag field (sun spots). used to m mag field on pho
Term
looped prominences
Definition
ionized gas ejected f suns pho following mag field out of srf and back in, along mag loops
Term
(2)flares
Definition
2 spots come ihop, their field lines join. mat t was following field lns explodes away f sun
Term
(3)sol cycle
Definition
22 yrs. every 11 yrs polarity (order of N/S lding/falling spots) is reversed. sm # spots start at high lats, move toward =tor and dec in #
Term
(3)parsec=
Definition
d at wh Es orbit gives a parallax of 1" (arcsec). PARallax in arcSEConds. =3.26 lt yrs
Term
(3)parallax=
Definition
displacement of obj viewed along 2 diff lns of sight. star appears shifted. exists bc E moves in spc
Term
(4)p=
Definition
half of total angular 2 bw lns. d(pc)=1/p (arcsec). closer objs have lger par. would be easier to m if E had lger orbit
Term
(3)w ground=based tels, we can m par
Definition
>.02 arcsec, d<50 pc. we cant see stars farther away th 500 pc
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