KPNO REU Students at the 221st AAS Meeting (January 2013)

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. All seven of the 2012 summer students attended the 221st meeting of the American Astronomical Society (AAS) at Long Beach, California in January 2013.

The abstracts of the REU student posters are reproduced below.

[144.15] Measuring Accretion Variability with H I Pfund Beta

Jonathan Brown (University of Michigan), C. Salyk (NOAO), K. M. Flaherty (University of Arizona)

We present multi-epoch accretion rates for 5 transitional disks observed as part of the NIRSPEC and CRIRES surveys of CO emission in circumstellar disks. Accretion rates are derived from Pfund Beta line flux using the relation outlined in Salyk et al. (in preparation). We find that the highest levels of variability we observe are less than ± 0.50 dex, suggesting that even the most variable objects in our sample exhibit fairly typical accretion variability. In the case of TW Hya, we find that HI Pfund Beta emission is uncorrelated with both CO fundamental emission and veiling estimates. Further investigation of the association (or lack thereof) between Pfund Beta and CO fundamental emission can be useful for placing strong constraints on the origin of accretion variability in protoplanetary disks. Brown was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[156.04] Characterizing Sky Brightness Throughout the Night in and around Tucson Arizona

Linsey J. Jensen (Utah State University), C. E. Walker (NOAO)

Five data-logging Sky Quality Meters were situated in and around Tucson Arizona while another three were placed on nearby mountaintops for about six weeks. The data from these instruments were used to understand how the sky brightness changes throughout the night in different locations around Tucson. As expected, the sky brightness of the mountains was dominated by natural light while the sky brightness of the city was dominated by artificial light. Unexpected results were that the sky got brighter during the course of the night on the mountains. This puzzle was solved using All-Sky Camera data. The night sky brightness was measured at one site with two separate instruments: a Sky Quality Meter and a Night Sky Brightness Monitor. The trend of changing brightness was in agreement with each other, but there was an unexpected offset between the values. Jensen was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA)and the NSF.

[147.33] Galaxy Merger Identification in the CANDELS GOODS-South Field

Erin O’Leary (Macalester College), J. S. Kartaltepe

We analyzed a catalog of 7,628 galaxies at 01. O’Leary was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[354.16] A Search for Stellar Activity in Eclipsing Binaries in the Kepler Field

Paige Romero (University of New Mexico), K. J. Mighell (NOAO)

Using Kepler light curves of eclipsing binaries we show that asymmetry of lightcurves is a useful tool in detecting stellar activity by detecting evidence of star spots. We created an algorithm to measure the goodness-of-fit of a period that is assigned to a given eclipsing binary as well as an appropriate period to each system. We created an asymmetry metric that measures the level of asymmetry of stars in the Kepler field. We demonstrate that asymmetry can indeed be explained by star spots by modeling a star, with an asymmetric light curve using star spots. We use a model of the RS CVn candidate V461 Lyr system as an example of this. Romero was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[345.19] Creating an Infrastructure for LSST All-Sky Camera Site Data

Amelia Shirtz (Northern Michigan University), T. Axelrod (University of Arizona), C. E. Claver (NOAO)

The science drivers behind the LSST project require that the LSST be able to observe in less than ideal conditions. Better knowledge of the structure function of clouds over the LSST site will assist with photometric calibration of LSST data. A program was created that identifies reference stars in an image from an all-sky camera located in Chile. The program then calculates an apparent magnitude and position data for the stars in the image and then these values are recorded. A pipeline was made to run an automated version of the program and to store the results in a database. Early light curves show that air mass extinction values can be extracted and cloud structures can be seen with the photometry data. The LSST project will be able to take the pipeline and use the output to model variations in clouds and air masses. Shirtz was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[242.04] Searching for the Magellenic Stream

Brianna Smart (University of Arizona), K. A. Olsen (NOAO)

The Large and Small Magellanic Clouds are two of the nearest galaxies to our own Milky Way, and have played important roles as astrophysical laboratories for understanding the stellar populations of galaxies. While they are known to be an interacting pair, they have always been viewed as distinct galaxies. In 2011, Olsen et al. made the surprising discovery that about 5% of the stars in the Large Magellanic Cloud appear to have their origin in the Small Magellanic Cloud. The result may explain the large amount of star formation activity in 30 Doradus, as that star-forming region is located where the accreted stream of SMC gas and stars appear to impact the LMC disk. We have reduced and measured velocities from ~2000 spectra that we collected in January 2012, with the goal of clearly establishing the origin of the accreted population of stars. We are now working on completing the spectral data analysis, modeling the full set of velocities that we now have, and measuring chemical abundances for a subset of the stars that we have discovered. Brianna Smart was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.