Transiting Extrasolar Planets orbiting HD 209458 and TrES-1

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Transiting Extrasolar Planets orbiting HD 209458 and TrES-1 Powered By Docstoc
					                                                     Near Earth Objects
                                                     Rozmin      Daya 1, 2,    Claud     Lacy 1, 3

      1. Arkansas Center for Space and Planetary Sciences, University of Arkansas, Fayetteville, AR 72701
                   2. Physics Department, Southern Methodist University, Dallas, TX 75275
                    3. Physics Department, University of Arkansas, Fayetteville, AR 72701




                Background                                       The NFO Telescope
                                                                                                                           2001 LF
•In order to collect a sample from an asteroid, it
is necessary to be able to track it and determine                                                             •Right Ascension: 17.08 hours
it’s rotation period.                                                                                          •Declination: -23.33 degrees
•One way to do this is differential photometry, a                                                           •Solar Elongation: 168.69 degrees
method in which images of an asteroid are taken
and then analyzed.                                                                                                  •V Magnitude: 14.87
                                                             The NFO telescope uses a 24 inch
•By monitoring the variation in brightness of the        Cassegrain reflector with a 2K by 2K                For both asteroids, RA and Declination
asteroid compared to comparison stars the                CCD camera on the back end.                     are as of 06-21-2005 (UT).
rotation period can be determined.                       Observations will be made using the
                                                         telescope’s R filter.

           Project Description
                                                                  Current Progress                                         Future Work
 • We will locate a NEO that is:
 1. in the correct RA range such that it will                                                           •We hope to modify Dr. Lacy’s program such that
                                                          Using the NEODys and ASTDys websites,         it will be able to track and measure any asteroid
  transit near the middle of the night. (RA           we have selected the asteroid 433 Eros for        as it moves.
  range 11 hours to 23 hours for the summer.)         study.
                                                                                                        •We also hope to improve upon the data
 2. Bright enough to observe using the NFO
                                                                                                        regarding the orbital elements of the NEO.
  telescope (brighter than magnitude 15).
 • W will obtain images hourly to determine
   the rotation period of the NEO. The images                            433 Eros
   will be measured using the program NFO
                                                            •Right Ascension: 13.17 hours                  References and Acknowledgments
   measure.
                                                             •Declination: -27.70 degrees
 • Dr. Lacy will modify his program NFO NEOs                                                            1) NEODys database.
   to automatically track and measure any                 •Solar Elongation: 116.65 degrees              http://newton.dm.unipi.it/cgi-bin/neodys/neoibo
   asteroid as it moves. We will compare the
                                                                  •V Magnitude: 12.21                   2) ASTDys database.
   observed positions of the asteroid with the
                                                                                                         http://hamilton.dm.unipi.it/cgi-bin/astdys/astibo
   predictions from the NEODys and ASTDys                  We are considering another asteroid, 2001
   databases and see if the orbital elements          LF, for study as well. Once we have obtained
   can be improved.                                                                                            The Arkansas Center for Space and
                                                      images of Eros, we will be able to determine if
                                                                                                              Planetary Sciences REU is funded by
                                                      2001 LF is too faint to observe using the NFO
                                                                                                                             NASA.
                                                      telescope.
Transiting Extrasolar Planets Orbiting HD 209458 and TrES-1
                                                       Rozmin     Daya 1, 2,    Claud      Lacy 1, 3

      1. Arkansas Center for Space and Planetary Sciences, University of Arkansas, Fayetteville, AR 72701
                   2. Physics Department, Southern Methodist University, Dallas, TX 75275
                    3. Physics Department, University of Arkansas, Fayetteville, AR 72701


                                                                  The NFO Telescope
                Background                                                                                    average intensity over the second and fifth
                                                                                                              (out-of-transit) orbits.”2 (Images were
•Extrasolar planets can be detected when they
                                                                                                              obtained using the Hubble Space
transit their parent star blocking a percentage of
                                                                                                              Telescope.)
its light.
•This can give information about: the planet’s
orbital period, radius, mass, density, and                      The NFO telescope uses a 24 inch
distance from it’s parent star.                            Cassegrain reflector with a 2K by 2K
                                                           CCD camera on the back end. For HD
                                                           209458, observations are being made
                                                           using B, V, and R filters; for TrES-1,
                                                           observations are being made using the
           Project Description
                                                           R filter.
 •Transits of the planets HD 209458b and
 TrES-1b will be photographed using the NFO                                                                              Current Progress
 telescope in Silver City, New Mexico.
                                                                    Data and Graphs
                                                                                                                 Currently we are using the telescope to
 •These images will be measured using the                    Below and to the left are the light curves
                                                                                                            obtain images of the transits. As we get the
 program Measure.                                       for TrES-1. The curves were constructed using
                                                                                                            images, we measure them. Once all data is
                                                        images from various telescopes in the Trans-
 •Light curves for the stars will be constructed.                                                           collected we will continue with the remaining
                                                        Atlantic Exoplanet Survey (TrES) network.
                                                                                                            steps of the project.
 •The light curves will be analyzed using the           Below and to the right is the orbital data for
 program EBOP, which uses the Nelson-                   TrES-1b.1
 Davis-Etzel model code.
 •Orbital data for the planets will be obtained                                                             References and Acknowledgments
 from these curves. We will try to improve on
 the orbital data from previous observations.                                                               1) Alonso et al., Astrophysical Journal
                                                                                                             Letters, 613, L153
                                                                                                            2) Brown, T. M., Charbonneau, D.,
                 “Schematic illustration of the
                                                                                                             Gilliland, R. L., Noyes, R. W., & Burrows,
                 light curve of a transiting planet.
                 Measurable quantities: duration                                                             A. 2001, Astrophysical Journal, 552, 699
                 of the transit l, the transit depth
                                                                                                               The Arkansas Center for Space and
                 d, the ingress/egress duration
                                                                                                              Planetary Sciences REU is funded by
                 w, and the central curvature of
                 the light curve C. “2                       Below is the light curve for HD209458.                          NASA.
                                                         This is the “phased light curve for all four
                                                         transits, assuming a planetary orbital period of
                                                         3.52474 days. The time series for each transit
                                                         has been scaled to have the same