The Parallelization and Optimization of the N-Body Problem using OpenMP and OpenMPI

The focus of this research is exploring the efficient ways we can implement the NBody problem. The N-Body problem, in the field of physics, is a problem in which predicts or simulates the movements of planets and how they interact with each other gravitationally. For this research, we are viewing if the simulation can execute efficiently by delegating the heavy computational work through different cores of a CPU. The approach that is being used to figure this out is by integrating the parallelization API OpenMP and the message-passing library OpenMPI into the code. Rather than all the code executing on a single thread, the computational work should be individually distributed based on the current nodes within the Barnes- Hut tree data. This research is an alternative to not only simulations alone but for also bigger data (which may require more distribution on work), or for computationally expensive procedures

The Study of Variability in Oxygen-Rich Proto-Planetary Nebulae

In this project, I am studying and analyzing the light and color variations for two proto-planetary nebulae (PPNe). PPNe is a stage in a star’s life where the star is in the process of losing its outer layers and exposing its core. I observed at the Valparaiso University Observatory, using the 0.4 meter telescope and an electronic camera to take digital images. I reduced these data using an image processing program to get the numerical data results. I plotted these results as a light curve showing the variation in brightness of the star versus time. By observing in three different filters, I also searched for variations in color to see if the change in color was correlated to the change in brightness (i.e., the star is hotter when brighter, cooler when dimmer, etc.). This is a long-term study and, in addition to my observations, there are 14 years of previous data on these objects. In the poster, I present the results of all the data for these two PPNe. They have periods of 114 days and 101 days, with a correlation between brightness and color; both show a cyclical variation in brightness with amplitude varying from year to year

A Possible Detection of Occultation by a Proto-planetary Clump in GM Cephei

GM Cep in the young (~ 4 Myr) open cluster Trumpler 37 has been known to be an abrupt variable and to have a circumstellar disk with very active accretion. Our monitoring observations in 2009–2011 revealed the star to show sporadic ?are events, each with brightening of . 0.5 mag lasting for days. These brightening events, associated with a color change toward the blue, should originate from an increased accretion activity. Moreover, the star also underwent a brightness drop of ~ 1 mag lasting for about a month, during which the star became bluer when fainter. Such brightness drops seem to have a recurrence time scale of a year, as evidenced in our data and the photometric behavior of GM Cep over a century. Between consecutive drops, the star brightened gradually by about 1 mag and became blue at peak luminosity. We propose that the drop is caused by obscuration of the central star by an orbiting dust concentration. The UX Orionis type of activity in GM Cep therefore exemplifies the disk inhomogeneity process in transition between grain coagulation and planetesimal formation in a young circumstellar disk

The Effect of Strong Electrostatic and Magnetostatic Fields on the Activity of Radioactive Nuclides

This experiment seeks to measure the effect of strong electrostatic and magnetostatic fields on the decay constant of short-lived radioactive isotopes. Though it is assumed in modern radioactivity theory that such fields should not have any measurable effect, conclusive evidence utilizing modern equipment is absent from published literature. Samples have been monitored that exhibit beta-minus, beta-plus, electron capture, and internal conversion modes of radioactive decay. Radioactive nuclides chosen for this study include I-128, Cs-134, and Cu-64. The half-lives in this collection of radioactive nuclides range from 25 minutes to 12.7 hours. Sodium Iodide detectors are used to monitor the samples both before and after they are placed in a strong static electric or magnetic field. Electric fields used in this study are about 20kV/cm and magnetic fields are inhomogeneous between 4.5kGauss and 7.5kGauss. From the data collected, the half-life of the sample during the time in the field is calculated, and this is compared to the normal half-life in the absence of strong electric or magnetic fields. This experiment is looking for very small deviations in the half-lives that escaped detection in earlier experiments that used cruder equipment

Optical Photometry and Spectroscopy of the Suspected Cool Algol AV Delphini: Determination of the Physical Properties

We present new spectroscopic and BVRI photometric observations of the double-lined eclipsing binary AV Del ( period = 3:85 days) conducted over six observing seasons. A detailed radial velocity and light-curve analysis of the optical data shows the system to be most likely semidetached, with the less massive and cooler star filling its Roche lobe. The system is probably a member of the rare class of ‘‘cool Algol’’ systems, which are distinguished from the ‘‘classical’’ Algol systems in that the mass-gaining component is also a late-type star rather than a B- or A-type star. By combining the spectroscopic and photometric analyses, we derive accurate absolute masses for the components of M1 = 1.453 + 0.028 M and M2 = 0.705 + 0.014 M and radii of R1 = 2.632 + 0.030 R and R2 = 4.233 + 0.060 R, as well as effective temperatures of 6000 + 200 and 4275 + 150 K for the primary and secondary, respectively. There are no obvious signs of activity (spottedness) in the optical light curve of the binary

Rotational Periods and Starspot Activity of Young Solar-Type Dwarfs in the Open Cluster IC 4665

We present the results of a V-band photometric monitoring survey of 15 late-type dwarfs in the young open cluster IC 4665. Low-amplitude periodic light variations are found for 8 stars and ascribed to the modulation by starspots that cover typically a few percent of the stellar disk. Periods range from 0.6 to 3.7d, translating to equatorial velocities between 13 and 93 km.s-1. That no period longer than 4d was detected suggests a relative paucity of extremely slow rotators (Veq \u3c\u3c 10 km.s-1) among late-type dwarfs in IC 4665. The fractional number of slow rotators in IC 4665 is similar to that of Alpha Per cluster, suggesting that IC 4665 is close in age to Alpha Per (~50 Myr)

Collation Model for LJS 490: [Astronomical compendium]

Collection of astronomical and astrological texts. Includes tables of solar declination (f. 13r), fixed stars (f. 22r), elevation of the pole star in various cities (f. 26r), new and full moons (f. 83r-84v), sightings and transits or eclipses of Venus and Mercury (f. 87r), and the position of the sun in the ecliptic (f. 87v); treatises on instruments, such as the astrolabe (f. 17r-22r, 29r-33v, 43r-49r, 50r-50v), the sundial (f. 23r-25v), the quadrant (f. 27r-28v, 78v), the Jacob\u27s staff (baculus, f. 45r-49r, 79r, 91r), and the chilinder or traveler\u27s dial (f. 77r-78v); treatises on other scientific subjects, such as practical geometry (f. 41r-42v), determination of the date of Easter (computus, f. 64v-67v, 70v-75r, 89r-90v), and analysis of urine (f. 68r-70r); digressions on the work of Johannes Sacrobosco (f. 35r-39r); and excerpts from the Compilatio de astrorum scientia of Leopold of Austria (f. 80r-81v). Cities in the Baden-Württemberg region of Germany are mentioned frequently, along with major cities in Europe, especially Italy.https://repository.upenn.edu/sims_models/1059/thumbnail.jp

Collation Model for LJS 361: [Astronomical and astrological tables].

Opening and closing sections of astronomical and astrological tables on either side of a remnant of commentaries on gospel and epistle readings. The opening section (f. 2r-9r) includes tables for calculating the day of the week for any day from 1204 to 1512; the Sunday letter from 1204 to 1736; the golden letter from 1215 to 1728; movable feasts; time variation according to latitude and longitude; the conjunction of the sun and moon from January to September from 1327 to 1367; and the hours of day and night in any day of the year, as well as lists of human activities and how they are affected by the moon and planets; parts of the body with the planet that dominates each part and appropriate medical activities; and parts of the body with the zodiac sign that dominates each part and appropriate medical activities. The central section (f. 10r-42r) comprises the last 3 gatherings of what were originally 13 gatherings of commentaries on the gospel and epistle readings for the temporal cycle compiled from sermons of French Dominican scholars Durandus of St. Pourçain and Jacobus of Lausanne. The closing section (f. 42r-46v) includes tables and lists for Biblical, classical, and Mideastern dates; the position in the third house of all the planets; the significance of each house; the power and virtues of the signs of the zodiac on the parts of the body, regions, plants, stones, and stars; the virtues of each house; the movement of each house; the properties of each planet; the properties of each sign; and the sun\u27s position in the zodiac arranged by month. Some early marginal drawings and notes.https://repository.upenn.edu/sims_models/1118/thumbnail.jp

Digital Imaging in the Introductory Astronomy Course

The availability of small, inexpensive CCD cameras is making it possible to offer non-science students in introductory astronomy courses hands-on experience in astronomical imaging. For the past three years at Gettysburg College we have been developing laboratory exercises using ST-4, ST-6, and Lynxx CCD cameras attached to 8-inch telescopes. We discuss the hardware and the procedures involved in these exercises, pointing out the benefits and limitations of digital observations with introductory students. We also offer tips for making successful observations with students, and describe plans for further development

A Desktop Universe for the Introductory Astronomy Laboratory

What is a well-intentioned astronomy instructor to do? There is no argument that experience with the real world is desirable in any astronomy course, especially the introductory classes that fulfill the science distribution requirements at many colleges and universities. Though it is a simple matter to take students out of doors, show them the motions of the Sun, Moon, and stars, and have them squint for a few seconds at Saturn\u27s rings through a telescope, these activities represent only a small portion of the subject matter of modern astronomy. It is simply not possible, given the constraints of time, weather, and equipment at most schools, to have students determine the photometric distance of a star cluster, measure the dispersion distance of a pulsar, or confirm Hubble\u27s redshift-distance relation for themselves. [excerpt