People

Dr. Ronald Olowin, Chair of the Physics and Astronomy Department, has been at Saint Mary’s since 1987. He is trained in observational cosmology and studies the large-scale structure of the universe by a detailed mapping of nearby clusters of galaxies. Dr. Olowin is a member of the International Executive Committee of INSAP, the “Inspiration of Astronomical Phenomena,” a group that brings together scientists and artists in an exploration of the arts and sciences. He is also a member of the Executive Board of the Science Secretariat of the International Federation of Catholic Universities, where he has given papers on issues as diverse as global warming and trans- and post-human development. Dr. Olowin brings his varied skills and interests to an experience-based learning environment. He has a number of research projects that can be used to train undergraduates on seismic, meteorological and astronomical measurements and related applications. He has been actively involved with Saint Mary’s summer research program, and his summer research students have presented their projects at annual Sigma Xi meetings.

Research Projects

NEO Search (Ronald Olowin)

Asteroids and comets with orbital distances from the sun similar to Earth's are designated as Near Earth Objects (NEOs). Earth-crossing asteroids (ECAs) and potentially hazardous asteroids (PHAs) have orbits with the potential for a close encounter or collision with the Earth. The threat of hazardous NEOs has gained greater attention in the public and press recently, in part as a response to several close encounters with asteroids discovered by the current national survey for such objects. Currently all asteroids and comets discovered around the world are reported to the Minor Planet Center of the Smithsonian Astrophysical Observatory at Harvard University. 

Small telescopes can play an important role in NEO monitoring and are well suited for tracking objects already discovered, which is crucial for analyzing orbital paths. Our research will be to observe a few bright NEOs and PHAs using the 40.6-cm SC telescope at the Geissberger Observatory at Saint Mary’s College. Due to the light-polluted sky of the Bay Area, the limit of this facility remains relatively modest (V=17), which allows minor planets to be observed mostly around opposition. Planning the observations in this case is actually simple, by searching the NEO Earth Close Approaches table maintained online by the NEO program.

The main goals of the observations will be oriented toward astrometry and photometry. Our instrumentation ensemble for this research consists of our robotic telescope, CCD camera and solid-state photometer. Initially, students will train intensively on the observatory equipment and learn observing protocols. The students’ first aim will be to recover bright, newly discovered NEOs/PHAs at their first opposition. The second aim will be to follow-up very desirable objects; VIs (very important), PHAs, and NEOs (Amors, Apollo, Athens) with One-Opposition and Multi-Opposition will be preferred in this order.

We have successfully completed a similar project in our 2006 School of Science Summer Research Program in which we detected and observed an uncatalogued asteroid. This research was awarded an "excellent" at the annual Sigma Xi conference.

Observing Optical Variations in Bright Quasars (Ronald Olowin)

The magnitude and timescale of variations in the luminosity of quasars provide crucial constraints on the mechanism of emission and the physical size of their emitting regions. For instance, variations by a factor of two in the infrared flux from the bright quasar 3C273 have been observed on a timescale as short as one day. Variations of this magnitude, over such short periods, are unprecedented. For example, in February 1988, the behavior of the source changed from having a stable infrared flux and slow optical variations (on timescales of weeks or months) to a state characterized by recurrent infrared and optical flaring. The optical variations were of several percent per day, changing from increase to decrease approximately every week. The amplitude of the repeated optical flares was 30–40%. The data are consistent with re-injection/acceleration of electrons followed by rapid cooling. 

These variations are detectable with modest aperture telescopes with sensitive detectors and data reduction packages. Student researchers will gain first-hand experience with observatory methods and astrophysical data acquisition, analysis and modeling. Our SSP-5 high-precision stellar photoelectric photometer will allow the student researcher to measure both bright and faint objects in the Ultraviolet-Blue-Visible-Red-Infrared spectral region with a great degree of precision and reliability. Its enhanced response time of 1 ms allows fast events to be recorded with great time resolution. A short-term tractable project is possible that will allow a mentored student to observe, analyze and report his or her findings.

We have prepared a catalog of bright Quasars that are accessible to our 16" SC telescope and will observe them nightly with differential photometric methods using our multi-color narrow band filtered photometer. Data reductions in our Advanced Computational Laboratory using the NOAO IRAF/DAOPHOT packages will include nightly magnitude comparisons of program objects to nearby standard stars with a calibrated magnitude sequence.

Saint Mary’s Seismic Research: Making Waves (Ronald Olowin)

Saint Mary’s College is a member of the Northern Hayward Fault Network sponsored by the University of California's Berkeley Seismology Laboratory (BSL), and has a high-gain long-period seismograph system on campus. The particular passbands of these instruments are nearly optimum, especially the vertical components, because Earth noise is approximately pre-whitened by the instrumental response, due to positioning in a 500' borehole on our campus.

The REU students will review and read events daily, making phase and amplitude readings from the broadband data, and determining the mechanism and moment. In addition to reading local and regional earthquakes, our students will routinely read larger teleseisms and report these observations to the National Earthquake Information Center and International Seismology Centre. The students will study seismic data acquisition, and modeling and analysis of information recorded by our borehole sensors. Students will analyze data produced by the seismometers: data recording begins as soon as the waveforms are acquired by BSL computers and ranges from automatic processing for earthquake response to analyst review for earthquake catalogs and quality control. Our students will also have access to data provided by the U.S. Geological Service Menlo Park for northern and central California. These data will be consolidated for the period of observation, analyzed, and prepared for publication.

Further, there is a significant probability of a major damaging earthquake on the U.S. west coast in the coming decades. To promote earthquake preparedness and mitigation, students will discuss and make a disaster plan as well as design a basic supply list that will reduce the impact of such seismic hazards. Field trips to the BSL and the U.S.G.S. Menlo Park will introduce students to the California Integrated Seismic Network to provide earthquake information on recent events. Students will also learn about the College’s participation in the Hayward Fault Monitoring Consortium