KPNO REU Students at the 209th AAS Meeting (January 2007)

The opportunity to present the findings of their original research at the most important national meeting of US astronomy is arguably one of the most prized benefits enjoyed by KPNO REU students. Five of the six 2004 summer students attended the 209^th meeting of the American Astronomical Society (AAS) in Seattle, WA in January 2007.

The abstracts of the five REU student posters are reproduced below.

[009.18] VLT Spectroscopy of Four Short Period Cataclysmic Variables

Julie N. Skinner (University of Oklahoma), S. B. Howell (NOAO), E. Mason (ESO)

VLT UVES spectroscopy of four short period, non-magnetic cataclysmic variable stars is presented. The stars observed were GW Lib, BW Scl, VY Aqr, and Z Cha. The 0.1A resolution spectra were uses to measure line strengths and velocity information. Using these measured values, physical parameters, such as the stellar masses, the binary inclination, and the nature of the accretion disk were determined. Mass constraints in the stars BW Scl and GW Lib strongly suggest that the mass donors are likely to be degenerate stars with masses less than 0.06 M-sun. Skinner's research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST- 0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[022.07] Analyzing the Focus Sensor Images for ODI at WIYN

Robert P. Nowicki (NOAO, Susquehanna University)

The WIYN (Wisconsin, Indiana, Yale, & NOAO) is building the One Degree Imager (ODI) for its 3.5m telescope at Kitt Peak. ODI is a wide field imager that is focusing on delivering the excellent image quality of the WIYN telescope. Maintaining good telescope focus is essential for the success of this instrument. A proposed technique for focusing ODI is using a CCD sensor that is tilted with respect to the instrument�s focal plane. We numerically analyzed images obtained with a prototype focus camera using several methods to determine the location of the best-focused stars. Specifically, a least chi-squares fit was used to fit a second order polynomial to the plot of FWHM versus pixel position along the CCD for the stars taken in these focus sensor images. Once ODI is operational at WIYN, one can use this algorithm to find the best FWHM and its position along the CCD, and feed this information back to the telescope control system. These numerical methods were implemented in the scripting language tcl/tk because of its easily built user interfaces and ready acceptance at Kitt Peak Observatory. R.P.N.'s research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[025.12] Constraining the Rotational Period for Component C of the Periodic Comet 73P/Schwassmann-Wachmann 3

Shaye Storm (NOAO, MIT), N. Samarasinha (NOAO, PSI), B. Mueller (PSI), T. Farnham (UMD), Y. Fernandez (UCF), A. Kidder (U. Washington), D. Snowden (U. Washington), M. A'Hearn (UMD), W. Harris (U. Washington), M. Knight (UMD), J. Morgenthaler (U. Washington), C. Lisse (APL/JHU), F. Roesler (U. Wisconsin)

Comet 73/Schwassmann-Wachmann 3 was imaged from May 3-10, 2006 UT with the narrowband H-B and broadband R filters. Observations were done at the 4-meter Mayall telescope on Kitt Peak, when the comet was near its perigee passage. Extensive temporal coverage of the two brightest fragments (Components B and C) was obtained over the observing run in addition to occasional monitoring of other selected fragments. We investigated the gas coma morphology of Component C using the CN filter, and the dust morphology using the BC, GC, and RC filters. The detailed coma morphology of the features was identified with the help of multiple image enhancement techniques. We analyzed the time evolution of the coma features in order to constrain the rotational period of the nucleus. Preliminary constraints resulted in a rotational period of 8.8 � 0.3, 13.2 � 0.3, and 27.2 � 0.3 hours. It is likely that the 27.2 � 0.3 hours period may be an alias of the first constrained period. We will compare our results with other investigators using different techniques (e.g. Radar data by Nolan, et al. 2006; HST data by Toth et al. 2006, Radio data by Kuppers et al. 2006). SS's research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program, which is funded by the National Science Foundation (NSF) through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF. NS was supported by the NASA Planetary Atmospheres Program.

[086.22] Maximizing Observations in the Large Synoptic Survey Telescope Cadence Simulator (OpSim) and Uncovering Its Abilities: Evaluating The Search for Variable Stars

Casey R. Coffey (NOAO, Westminster College), A. Saha (NOAO), M. Miller (NOAO)

The Large Synoptic Survey Telescope (LSST) is a proposed 8.4 meter ground-based survey telescope to be built in Cerro Pachon, Chile and is scheduled for completion in late 2012. It will perform a ten year survey of the night sky, utilizing its wide ten square degree field of view to dynamically survey the sky using frequent 30 second exposures. The LSST cadence simulator (OpSim) is a computer simulation model that has been developed to mimic the cadence scheme of the LSST. Using the LSST cadence simulator, we examined the dates of observation of several fields of the sky, and using this data and several methods of period analysis attempted to determine the feasibility of using the LSST as a search tool for types of variable stars with known periods. This research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[165.02] WIYN Tip-Tilt Module Observations of the Old Open Cluster NGC 1193

Myra J. Stone (NOAO, University of Georgia), C. F. Claver (NOAO), K. J. Mighell (NOAO)

We present the analysis of new photometric data in the BVI system of the old Galactic open cluster NGC 1193 obtained at the WIYN 3.5 m on Kitt Peak with the WIYN Tip-Tilt Module. CCD image reductions were performed using IRAF's CCDRED package and final photometry was obtained with IRAF's DAOPHOT package. Our preliminary results from the analysis of five color-magnitude diagrams with the 2004 Yonsei-Yale isochrones give an age estimate of 5 Gyr for NGC 1193 which is 3 Gyr younger than the original estimate of Kaluzny in 1988 and the reanalysis of the same data by Tadross in 2004. Although our metallicity estimate for NGC 1193 is [Fe/H]=-0.30 is in agreement with those of Kaluzny and Tadross, we find that the cluster has a significantly higher apparent distance modulus in V of (m-M)_V = 14.12 mag due to our larger reddening estimate of E(B-V)=0.20 mag which is in agreement with the E(B-V)=0.21 mag estimate of Schlegel, Finkbeiner, and Davis that was based on their analysis of infrared dust maps. We discuss the impact this new analysis of NGC 1193 has on our understanding of Galactic open clusters. Myra Stone's research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.