http://hdl.handle.net/1803/686 2013-05-23T01:22:16Z http://hdl.handle.net/1803/4838 Title: Measuring Radial Velocities of Low Mass Eclipsing Binaries Authors: Rattray, Rebecca Abstract: Due to the complex nature of the spectra of low-mass M type stars, it is difficult to determine their metallicities and temperatures directly. By studying eclipsing binary pairs comprising one F, G, or K type star with an M type star, we are able to use what we know about the primary star to learn more about the secondary star. Measuring the orbital reflex motion of the primary star, together with the eclipse light curve of the M star as it transits the primary star, allows us to determine the mass, radius, temperature, and metallicity of the M star. We studied 23 low mass eclipsing binaries (EBLMs) previously discovered by SuperWASP photometry. We obtained spectra using the Cerro Tololo Inter-American Observatory (CTIO) SMARTS 1.5-meter echelle spectrograph between June 2009 and January 2011. Each EBLM target was typically observed ~8 times over this time period. The spectra were processed using standard astronomical software, and a cross-correlation method was used to measure the radial velocity of the target star at each observed epoch. Radial velocities were successfully determined for 21 of the 23 EBLM target objects. Orbital periods, radial velocity amplitudes, and eccentricities for these EBLMs could be determined from these radial velocities together with the preexisting light curves. Using these values and by assuming a mass for the primary star, we will be able to calculate the masses of the secondary M type star in each EBLM system. 2011-04-01T05:00:00Z http://hdl.handle.net/1803/4107 Title: The distribution of ejected stars around a super massive black hole binary due to three-body scattering Authors: Benson, Amanda Description: Honors in Astronomy 2010-04-01T05:00:00Z http://hdl.handle.net/1803/2944 Title: Blazar Microvariations Authors: Pittman, Cameron W. Abstract: In November 2006, the authors collected data on blazars PKS 0537-441, PKS 0447-439, and PKS 0208-5121 from the Cerra Tololo Inter-American Observatory in Chile. All three blazars are tested for microvariability, first by comparing relative magnitudes against unvarying stars, then through power spectrum analysis. The authors used GNU Scientific Library tools for the Fourier transforms needed for power spectrum analysis. Fourier transforms break down data into series of periodic functions. Running power spectra quantitatively illuminate periodicity and variability in data. The authors tested power spectra by using well-defined functions to better understand power spectra analysis. Through light curve analysis and power spectra analysis, the authors found PKS 0537-441 showed microvariability, PKS 0208-512 most likely did not show microvariability, and PKS 0447-439 did not show microvariability. Description: Honors in Astronomy 2009-04-20T05:00:00Z http://hdl.handle.net/1803/730 Title: Exploring the Local Association : a nearby, young kinematic stream of stars in the solar neighborhood Authors: Saling, Chris Abstract: During the course of my Honors Research Project, I worked with Dr. David James to determine whether a group of target stars are members of the Local Association. I did this by reducing spectroscopic data, taken by Dr. James, in order to determine the radial velocity and lithium contents of the stars. Using the radial velocity measurements, the kinematics of each star was then defined by determining their U,V,W space motions. Lithium measurements were used to establish star youth and provide further evidence to support membership of the Local Association. Description: Honors in Astronomy 2008-01-01T06:00:00Z