archive-ca.com » CA » Q » QUEENSU.CA

Total: 401

Choose link from "Titles, links and description words view":

Or switch to "Titles and links view".
  • APSC 112 menu
    Longitudinal wave 2 6 Power in a Transverse wave Example 2 7 Intensity Sony 2 8 Reflection and Transmission of waves Link 2 9 Superposition of waves Review Resonance Example Example Piano Link 2 10 Beats Spruce Goose Link Aside 2 11 Doppler effect Relative velocities Example Formula Sheet Link 2 12 Engineering Example Link Link 3 Electric Fields 3 1 Electrostatics Example 3 2 Properties of Charge 3 3 Electric Field Introduction 3 4 5 Point charge and Dipole Example Link 3 6 Charge Distributions 3 7 Linear Charge Density 3 8 Surface Charge Density 3 9 Charge in an Electric Field Application Wimshurst Machine 3 10 Review More Midterm 1 Review Midterm 1 2014 Solutions Midterm 1 2013 Solutions Review Student Questions More 4 Electric Potential 4 1 Electric Potential Energy and Potential 4 2 V from E 4 3 Point Charge Potential Examples 4 4 Dipole Potential 4 5 Potential for continuous distributions Examples 4 6 Isolated conductors Review E and V example advanced 4 7 E from V 5 Current and Resistance 5 1 Electric Current 5 2 Current Density Summary 5 3 Resistance Cylindrical Conductor Example 5 4 Ohm s Law 5 5 Energy and Power 6 Circuits 6 1 EMF 6 2 Calculation of Current 6 3 Potential Differences Examples 6 4 Multiloop Circuits Examples Example Circuit Demo 6 5 Measuring Instruments Example 6 6 Engineering Example Midterm 2 Review Midterm 2 2014 Solutions 2014 Midterm 2 2013 Solutions 2013 MCSolutions 2013 Midterm 2 2012 Solutions 2012 Practice Problems with Solutions Multiloop question Tutorial W9 P4 Tutorial W9 P5 Workbook 6 31 7 Magnetic Fields and Forces 7 1 Definition of B 7 2 Discovery of the Electron 7 3 Hall Effect 7 4 Circulating Charge 7 5 Force on a current carrying wire

    Original URL path: http://www.astro.queensu.ca/~lake/112/menu.html (2016-02-13)
    Open archived version from archive


  • SquirrelMail - You must be logged in to access this page.
    SquirrelMail version 1 4 8 21 el5 centos By the SquirrelMail Project Team ERROR You must be logged in to access this page Go to the login page

    Original URL path: http://www.astro.queensu.ca/webmail/src/redirect.php (2016-02-13)
    Open archived version from archive

  • observing
    Point the telescope at the calibrator and obtain a CCD image of it By trial and error find an integration time which gives a high count without saturating the image saturation occurs at 65 535 counts It is okay to saturate other objects in the field but not the object to be measured the calibrator in this case Keep in mind that if the source is rising the counts will increase as the airmass decreases Point the telescope at the asteroid of interest and obtain a CCD image again choosing the integration time by trial and error Choose an RA and DEC for a time which corresponds to the midpoint of your observing session and use the same coordinates for the center of the field over the entire observing session unless it becomes obvious that the asteroid will move out of the frame in which case a shift in coordinate will be required The asteroid will slowly move with respect to background stars over the session This motion should become apparent within about 10 minutes For example asteroid James Bradley moves 0 48 min from ephemeris output Thus after 10 minutes this asteroid will have moved 4 5 arcseconds which is 3 75 pixels If the same calibrator is used for all asteroids the sequence could be calibrator asteroid 1 asteroid 2 asteroid 3 asteroid 4 asteroid 1 asteroid 2 etc The calibrator should be observed 3 times over the observing session once at the beginning once in the middle and once at the end The reason for multiple calibrator observations is to allow for changing sky conditions over the observing session and to use the calibrator closest in time to the asteroid observation If different calibrators are used for different asteroids then each would have to be observed 3

    Original URL path: http://www.astro.queensu.ca/~irwin/phy215/y2002/observing.html (2016-02-13)
    Open archived version from archive



  • data reductions
    same for the calibrator This routine will correct for the brightness of the sky background since it measures the counts above some background level It is now necessary to measure the counts in the same way from a non varying star in each field Students should choose a relatively bright star in the field which is not saturated i e the peak reading should not be 65 535 counts and ensure that the same star is visible and not saturated in each field over the observing session This will be called the comparison star This is done for any asteroid observed For each asteroid calculate a differential magnitude m diff in each image via m diff m comparison m asteroid 2 5 log counts c counts a where counts c is the total counts of the comparison star and counts a is the total counts of the asteroid A plot of m diff as a function of time will reveal the light curve of the asteroid over your observing session For this plot use the Julian Date to at least 4 decimal places as listed in the image header D Reduction to V Magnitudes A plot of m diff as a function of time for both the asteroids should be sufficient to reveal any variation due to asteroid rotation on time scales of order the observing session or smaller However it is likely that only a fraction of the total period has actually been measured This means that students need to combine their data with those taken by others of the same asteroid If students simply combine their m diff with those of other students the periods should agree but the amplitudes will all be different because other students may have chosen different comparison stars Thus students now need to reduce their data to a standard V magnitude before the data are combined During the observing session students observed a standard calibrator with a known V magnitude we assume that the calibrator is not varying If the above instructions were followed students now have a counts value for the calibrator at various times throughout the observing session Since the calibrator is not varying in time we assume its V magnitude will be constant but its count rate will change because it is being observed at different times and through different air masses It is therefore necessary to determine how the calibrator s count rate varies as a function of air mass This can be done by plotting a graph of log counts cal t cal as a function of sec z where t cal is the integration time for that calibrator observation and z is the zenith angle The zenith angle can be found from z 90 e where e is the elevation recorded at the observing session also given in the file header The result should be a straight line or close to it This graph can then be used to convert the asteroid count rate into a V

    Original URL path: http://www.astro.queensu.ca/~irwin/phy215/y2002/reductions.html (2016-02-13)
    Open archived version from archive

  • period determination
    finds the best periods possible from the data The period finding algorithm fits a series of sine waves of different amplitudes and frequencies in a systematic fashion until the best fit is achieved This process is called Fourier Analysis Note that it may be possible to extract several periods if say the observer consistently takes observations at some multiple of the actual period In such cases the correct period is not found but the observer at least knows that the period can be one of a limited number of possibilities Another case is that only a few points on the light curve might have been obtained not enough for a period to be determined In that case the period can sometimes still be constrained with error bars or the algorithm will fail altogether The solution to either of these cases is to simply acquire more data In a best case scenario with sufficient data the period can be determined uniquely though of course there will still be measurement errors An examination of the plot by eye may in the first instance allow students to put limits on the period if sufficient data have been obtained and students are encouraged to

    Original URL path: http://www.astro.queensu.ca/~irwin/phy215/y2002/period.html (2016-02-13)
    Open archived version from archive

  • final report
    to copy and modify any of the pages under Irwin s home page for this purpose For those who wish more information other reference sources are A Beginner s Guide to HTML or Introduction to HTML Students who are submitting an html file should call it yourname html Submit this file plus any associated files e g gif files by emailing them to irwin astro queensu ca and I will put them in an appropriate area for viewing B Content Although the data will overlap with other students each student is expected to present the results of his or her own project independently The report should be written up like a lab i e Introduction Observations Data Reduction Discussion and Conclusion Include whatever you have already included in the progress report most likely the observing log and raw data in the final report as well Aside from the usual representation of data results I am especially interested in knowing what you have learned by doing the project and what pitfalls and successes there have been along the way If possible include recommendations For example did you find that say 3 minutes was sufficient to obtain a good signal to noise on the asteroid or would a longer time have been better If a longer time is better what does this tell you about the optimal magnitude range for asteroids for a project like this Did the quality of the result depend on where the asteroid was placed on the CCD chip Etc Such information is useful and will help to improve the project in the future For asteroids for which a light curve has been obtained comment on its quality If a period has been determined again comment on how secure it might be and compare it to any previously

    Original URL path: http://www.astro.queensu.ca/~irwin/phy215/y2002/final_report.html (2016-02-13)
    Open archived version from archive

  • progress report
    been picked up by the routine of which I have plotted only the first two most likely periods found by the program I have done this only for Ate and for Burdigala since the data for Liberatrix and Pawona are too sparse to determine any periods Please see the asteroid magnitude database for plots of Liberatrix and Pawona In the plots below the x axis indicates the time in hours

    Original URL path: http://www.astro.queensu.ca/~irwin/phy215/y2002/results.html (2016-02-13)
    Open archived version from archive

  • Useful Links
    Orbital Parameters SLOP can choose asteroids near opposition The Uppsala Astronomical Observatory Asteroid Page Rotation periods of asteroids are listed NASA s Near Earth Object Program University of Iowa Asteroid Rotation Lab John Hoot s asteroid rotation page Palmer Divide Observatory s asteroid rotation page Herzberg Institute of Astrophysics of Canada s NRC rise set tables Generates sunrise set times for Kingston for any day of the year Solar ephemeris

    Original URL path: http://www.astro.queensu.ca/~irwin/phy215/y2001/links.html (2016-02-13)
    Open archived version from archive



  •