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Full-Text Articles in Physical Sciences and Mathematics
A Long-Term Variability Study Of Dying Low And Intermediate Mass Stars, Allyse Appel, Justin Reed
A Long-Term Variability Study Of Dying Low And Intermediate Mass Stars, Allyse Appel, Justin Reed
Symposium on Undergraduate Research and Creative Expression (SOURCE)
We are studying the long-term light variation of dying stars (similar to the sun). These stars pulsate, causing them to vary in light. Our purpose is to better understand the internal structure of these objects though light curve and period analysis. These dying stars are in the proto-planetary nebula (PPN) phase, which lasts only a few thousand years between the red giant phase and the planetary nebula phase. First discovered with the Infrared Astronomical Satellite Survey in 1983, PPN emit strongly in the region, but the central stars of PPN can be studied in visible light. This summer we have …
Binary Stars In Planetary Nebulae, Hannah Rotter
Binary Stars In Planetary Nebulae, Hannah Rotter
Symposium on Undergraduate Research and Creative Expression (SOURCE)
When a star like the sun dies, it swells into a red giant and then expels its outer layers to form a planetary nebula. Eventually the outer layers leave the leftover core and it becomes a white dwarf. The cause of the many exotic shapes in the planetary nebulae is unknown; however, it is thought that binary stars may play a role in the shaping process. In this project we are studying the central stars of planetary nebulae to see if they vary in brightness, and to see if that variability is due to the central star having a binary …
A Study Of Two Newly-Discovered Eclipsing Binary Systems, Austin Bain
A Study Of Two Newly-Discovered Eclipsing Binary Systems, Austin Bain
Symposium on Undergraduate Research and Creative Expression (SOURCE)
I have observed three newly-discovered variable stars using the 16-inch telescope and CCD at the Valparaiso University Observatory. Of these three variables, two have been verified as binary star systems, where one of the stars passes in front of the other. The third is found to be a pulsating variable, which varies due to a change in its size and temperature. One of the goals of this project has been to further refine the periods of these three variables. From my new data and some previous observations at the Valparaiso University Observatory, I have been able to determine that the …
Neutral Pion Background Analysis At Star, Adam Clark
Neutral Pion Background Analysis At Star, Adam Clark
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The STAR detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory takes measurements of polarized proton collisions which can then be used to extract cross sections and spin asymmetries. The Endcap Electromagnetic Calorimeter (EEMC) in STAR allows measurements of electromagnetic particles in the forward direction, 1 < η < 2. The EEMC will be used to determine the neutral pion (π0) cross section and the double longitudinal spin asymmetry (ALL) which gives us information about the gluon contribution to the proton’s spin. The π0 cross section is an important supporting measurement to verify our signal reconstruction and the background characterization for the π0 asymmetry. In order to measure the π0 cross section and asymmetry, the backgrounds must be well understood (such as those from photon conversions and reconstruction errors where one photon reconstructs as two clusters). Efforts toward the π0 cross section and asymmetry measurements and, specifically, those to understand π0 backgrounds are discussed.
An Event-By-Event Comparison Of Clustering Algorithms For Photon Detection In The Star Endcap Calorimeter, William J. Pochron
An Event-By-Event Comparison Of Clustering Algorithms For Photon Detection In The Star Endcap Calorimeter, William J. Pochron
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The STAR detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory uses polarized proton collisions to determine the origin of the proton spin, using measurements such as neutral pion asymmetries. The Endcap Electromagnetic Calorimeter (EEMC) in the STAR detector is especially useful for detecting photons from π° decays at forward angles. This latter measurement is obtained from the Shower Maximum Detector (SMD) in the EEMC where narrow crossed scintillator strips measure the energy deposited in them and can be used to identify the location of the photon shower. The electromagnetic shower most often deposits energy in a …
Dispersion Of Radon-222 Gas In Air, Erin Beckmeyer
Dispersion Of Radon-222 Gas In Air, Erin Beckmeyer
Symposium on Undergraduate Research and Creative Expression (SOURCE)
Radon-222 is a heavy radioactive gas with a half-life of 3.8 days, often found in basements and other enclosed, underground spaces. It is produced by decaying deposits of uranium-238, and presents a significant health risk to those who encounter it in their homes and places of work. The only gas in the uranium decay chain, radon atoms work their way through layers of soil, usually to dissipate harmlessly into the atmosphere. In buildings, however, the gas accumulates and causes dangerous environmental radiation. Much work has been done to measure the transmission of the gas through water and solid materials, but …
Generating A ‘Clean’ Pi0 Spectrum In Star, William J. Pochron
Generating A ‘Clean’ Pi0 Spectrum In Star, William J. Pochron
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The STAR detector at Brookhaven National Laboratory’s Relativistic Heavy Ion Collider uses polarized proton collisions to investigate the origin of the proton spin, using measurements such as neutral pion (π0) asymmetries. STAR’s Endcap Electromagnetic Calorimeter (EEMC) is especially useful for detecting photons from π0 decays at forward-angle scattering from ≈15 to ≈40 degrees above the beam direction. We identify π0’s by constructing invariant mass spectra from these photons. Large background contributions are present in these spectra and distort the true value of the π0 invariant mass. By applying constraints (cuts) on parameters such as the opening angle of the photons …
Stability Of The Gains Of The Star Endcap Calorimeter From 2006 To 2011, Kayla Kutz
Stability Of The Gains Of The Star Endcap Calorimeter From 2006 To 2011, Kayla Kutz
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The Solenoid Tracker at RHIC (STAR) experiment, based at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC), uses polarized-proton collisions to investigate sea quark and gluon contributions to the fundamental proton property called “spin.” The STAR detector's Endcap Electromagnetic Calorimeter (EEMC) measures the energy of particles produced by those collisions using a lead-scintillator sampling calorimeter, consisting of several layers that include pre-shower, shower maximum, tower, and post-shower detectors. In these detectors, the energy gains, which convert a measured pulse into an energy deposition, have been determined using data taken from the years 2006, 2009, and 2011. Changes in the gains …
Testing The Klein-Nishina Model For Compton Scattering Of 0.662 Mev Photons With A Focus On Lower Scattering Angles, Joel Rogers
Testing The Klein-Nishina Model For Compton Scattering Of 0.662 Mev Photons With A Focus On Lower Scattering Angles, Joel Rogers
Symposium on Undergraduate Research and Creative Expression (SOURCE)
The Thomson and Klein-Nishina equations for obtaining the differential cross section by Compton scattering of photons from free electrons in aluminum will be tested using 0.662 MeV photons from a Cesium-137 source. A NaI detector will be used to count the number of photons scattering from the target as a function of the scattering angle. A previous experiment carried out by VU student Josh Vredevoogd showed good agreement with the Klein-Nishina theory for angles greater than 45 but discrepancies with angles less than 45 degrees. This experiment will concentrate on testing the Klein-Nishina theory at angles less than 45 degrees.
A Study Of Light Variability In Dying Stars, Hannah Rotter, Aaron Seider, Austin Bain
A Study Of Light Variability In Dying Stars, Hannah Rotter, Aaron Seider, Austin Bain
Symposium on Undergraduate Research and Creative Expression (SOURCE)
In this research project, we observed and analyzed the light variability in a class of dying stars that are in the stage between Red Giant and White Dwarf in the evolution of stars like the Sun. Our observations were carried out during the summer and fall of 2012 at the Valparaiso Observatory. Thirty-two of these objects were observed in total. We analyzed a subset of 18 of these and found that they all varied in visual brightness by 10-70 percent. Periods for the variability were found for 8 out of 18 objects, and they range from 27 to 125 days, …