Visions of the Universe
Visions of the Universe ISP 205
Popular in Course
Popular in Integrative Studies Physical
This 8 page Class Notes was uploaded by Ms. Mckenzie Labadie on Saturday September 19, 2015. The Class Notes belongs to ISP 205 at Michigan State University taught by Eugene Brown in Fall. Since its upload, it has received 33 views. For similar materials see /class/207718/isp-205-michigan-state-university in Integrative Studies Physical at Michigan State University.
Reviews for Visions of the Universe
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/19/15
Galaxies 39 Test 3 New date How do astronomers measure 39 7 7 Thurs 9 Aprll the mass of galax1es I I Most of the mass of galaxres IS 7 One cheat sheet dark matter 7 study guide amp practice What clue indicates the test presence of newly formed stars Other galaxies Elliptical spiral Link on syllabus Add Jovian planets amp lrregu ar Ignore neutron stars amp black holes 7 Class of 326 history of low and highmass stars is included Weighing the Sun To nd mass of sun measure period T amp size R of a planet s orbit r Kepler s 3 1 Law GM 47Z R3 TZ r M R3 TZ for R in AU T in years andM in solar masses A planet moves under in uence of the gravi of the sun The planet moves once around the sun in a speci ed orbit If the time is short the mass of the Fquot A greater B less 3 Astronomers measure the mass of the sun by A putting the sun on bathroom scales measuring the motion of something that orbits it C guring out how much gas is in the sun Mass Test object Motion Behavior if more massive Sun Earth An orbit Period is shorter Eros Earth A ball Drops lm Time is shorter Galaxy 9 Wei ghng a Galaxy To find mass of sun measure period T amp size R 7 Kepler s 3 Law GM 472 R3 T2 7 M R3 T2 for R in AU T in years and M in solar masses A planet moves under in uence of the gravity of the sun The planet moves once around the sun in a specified orbit Ifthe time is short the mass of the sun is greater Write an equivalent statement for the galaxy NGC 3672 Mass Test object Motion Behavior if more massive Sun Earth An orbit Year is shorter Eros Earth A ball Drops lm Time is shorter Galaxy A gas cloud 9 Weighing a Galaxy To find mass of sun measure period T amp size R I n 7 Kepler s 3 Law GM 472 R3 T2 7 M R3 T2 for R in AU T in years and M in solar masses A gas cloud moves under in uence of the gravity of the galaxy The gas cloud moves once around the galaxy in a specified orbit If the time is short the mass of the galaxy is greater Write an equivalent statement for the galaxy NGC 3672 Mass Test object Motion Behavior if more massive Sun Earth An orbit Year is shorter Eros Earth A ball Drops lm Time is shorter Galaxy A gas cloud Use Doppler effect Kepler s Law needs modi cation since period of sun s motion around Milky Way is 200 Myr Mass R3 T2 R IV T2 Mass R v2 Doppler effect for measuring speed Most mass here not where stars are 7 No need to wait to see motion 7 Speed is imprinted in the light l Weighing using Doppler effect Measure period T amp size R of a planet s orbit to find the mass M 7 Kepler s 3 Law 7 GMoc4 rr2R3T2 7 M R3 T2 for R in AU T in years and M in solar masses MRvZ 7 Measure velocity with Doppler effect Useful in astronomy ofsun s orbitis 200Myr Alien astronomers want to measure the mass of the sun using the Doppler effect of light emitted by Jupiter If the mass of the sun is greater they would measure a shift in wavelength A smaller B bigger Mass Test object Motion Behavior if more massive Sun Earth An orbit Year is shorter Eros Earth A ball Drops lm Time is shorter Galaxy A gas cloud Most mass here not where stars are Dark Matter Vera Rubin amp colleagues measured the speed of 3672 gas orbiting NGC MR is mass enclosed withinradius R esl In err 12 22 quota 17520 of 0131 est K s 3rd Law 5 s DOtS MR is proportional to v2 R m WM mm un tJ woos NGC3672 H mm 7 vR rises from 0 to 7 kpc 0m 7 vR is constant beyond 7kpc Mass MR we 39 Jr139 noon 7 Between center and 7 kpc MR rises steep 39 ooal because bot v and R increase I A 0 ca YX JAD ac 314an w aux Between 7 amp 16 kpc MR rises linearly 7 There is little light beyond 7 kpc 7 Where thereis mass there is not necessarily light from stars amp as 7 Eaxltmpolate MR is linear beyond visible part of For the Milky Way Galaxy this extrapolation was tested with satellites of Milky Way Surprising conclusion Most of mass of galaxies is not in stars amp gas 4 1 Vera Rubin 1928 two library ucla Edu imagesmum Mpg N U HII region gas cloud with 0 stars Which is the hottest star A G D M Which type of star has the shortest life Which type of star emits light with the most energy Wein s Law kpeakTconst Energy of a photon is proportional to 17 Electron falls to a lower Hydrogen level Falling from 3to2 causes Visible emission line of H red light to be emithad Red quotlie isjjlfmp 3amp2 Presence of red line of H Cyan llne IS Jump 4amp2 indicates 0 stars Blue line is jump 5amp2 0 Stars have been forming In a cool Cloud of very recently 0 stars live only 20Myr hydrogen the electrons areE in level 1 i lfthere is a nearby 0 star 39 i there are lots of photons 3943 with enough energy to ionize hydrogen Proton captures electron inml A a high energy level 712 Out VIilky Way 0 0 Young stars dust amp gas in disk Circular orbits Old stars in halo Elongated orbits HoW are other gala fferent from the Willqr Wav 39 3e of star G as Dus its I 39 r 39 39 rkniatte lj39galaxy in the Virgo vCluste39r39come to its present form I quot 039 History of galaxies 5 g Barred Spiral Irregular EII39 t39 IP pa Spiral Irregular Barred Spiral Which type of galaxies have no young stars a Elliptical b Spiral c Barred Spiral 1 Irregular Which type of galaxy has the most gas Stars form out of gas For there to be 0 stars there must have been gas 20 Myrs ago Compare to age of the sun 45Byrs Elliptical Galaxy M87 Cluster Virgo Cluster has hundreds of galaxies No gas No young stars No dust 0 Halo Globular clusters Dark matter M87 in center of Virgo 2 M5 i Gas Young stars Dust Halo Globular clusters Dark matter In this picture what is evidence that this galaxy has young stars a Blue color Bright center Spiral structure Dark regions Red clouds ip09quot Spiral Galaxy The Search for Pluto The Search for Pluto 19051 30 19051930 Uranus dis vered 1781 Wh0e Search gfur camets rregular 39es in orbit fUranus Juwtev nemmw 5 51175077 unexpai edl39Ieguailies nether pl et What is Pluto Ilka Pluto s Size Triton the largest moon ofNeptune 1700 mHe mameter Etggerthan Pmto Prabamy 75 rack Ce mscavered VanW NZ ha fthe STZe ufF mtu atmasphere New camd measure Pmta39s 33 Wed b Ne we mamas Em y m 2 gm ea Puto I smell Om saxtstmed 157quot Eptune s 5 0 002 Earth mass 0 10 Earth mametermuu rm Blggeslnbjecls ce 39 u More 5 me Erls It w M Ku39PerBe39t e objects keep mamML being Largest knuwn KBO may get omen dlscovered39 39 5 bwggerthan F39mta lt annst known Kmpur Eult abtncta The sphenczl manalnm 0qu 45 It thDE nae asu quot Wyn I In My sum The omen mm mm slrenglhens ma meow m Kumev sane ec WWquot quotquot392
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'