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 205th meeting of the American Astronomical Society (AAS) in San Diego, CA in January 2005. Abstracts of the 6 REU papers for the January AAS meeting were published in the Bulletin of the American Astronomical Society, v.36, no. 5, 2004 and are accessible online at the AAS web site http://www.aas.org/publications/baas/v36n5/aas205/ .
The abstracts of all six REU student posters are reproduced below.
[15.03] The Stellar Birthline and Birth-Rate Function in IC 1805: A Feasibility Study
L. Kushner (U. Washington & NOAO), S. C. Wolff, S. E. Strom (NOAO)
AAS 205th Meeting, 9-13 January 2005 Session 15 Young Stellar Associations Poster, Monday, January 10, 2005, 9:20am-6:30pm, Exhibit Hall
HR diagrams for the youngest, optically-visible clusters potentially encode (a) the range of mass accretion rates, dM/dt, that characterized the stellar assembly phase; and (b) the rate of star formation as a function of mass, N(M,t). In this contribution, we make use of published photometry and spectroscopy for the young cluster IC 1805 to explore the factors that influence our ability to deduce dM/dt and N(M,t), and to suggest observations that could in principle provide more robust constraints on these quantities.
[143.10] A Hunt for Red Quasars: A Deep Wide-Field Infrared Survey
M. K. Nordhaus (NOAO/RPI), R. F. Green (KPNO), A. Dey (NOAO), D. Norman (CTIO), K. Brand (NOAO), S. Croom (AAO), S. Warren (Imperial Coll.), P.B. Hall (York), M. I. Brown (Princeton), B. Jannuzi (NOAO), P. Smith (Arizona), M. G. Smith (NOAO), G. Tiede (BGSU), P. J. Green (SAO), D. Eisenstein (Arizona), C. Kochanek (OSU)
AAS 205th Meeting, 9-13 January 2005 Session 143 Quasars Poster, Thursday, January 13, 2005, 9:20am-4:00pm, Exhibit Hall
When determining the contribution of QSOs to the universal energy budget over the optical-infrared window as a function of cosmic time, a fuller census of accreting objects must include the impact of dust in the host galaxy, in the circumnuclear torus, and in intervening absorbers. Samples of QSOs are isolated using the general fact that QSO spectral energy distributions differ from those of stars. Using the UV-excess selection method, red objects may fall outside of the color selection limits or onto the stellar locus causing them to be excluded from surveys. We use the unique optical and IR deep imaging data provided in the Bootes field of the NOAO Deep Wide-Field Survey to select our quasar candidates. Drawing from a K-limited color-outlier sample with 169 spectroscopic redshifts, we derive an estimate for the fraction of moderately reddened quasars.
Nordhaus’ 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.
[54.18] Flickering Red Giants in the Ursa Minor Dwarf Spheroidal Galaxy: Detection of Low-Amplitude Variability in Faint Red Giant Branch Stars on Ten-Minute Timescales
I.U. Roederer, K.J. Mighell (NOAO)
AAS 205th Meeting, 9-13 January 2005 Session 54 Pulsating Stars: RR Lyraes, Miras, Cepheids, etc. Poster, Tuesday, January 11, 2005, 9:20am-6:30pm, Exhibit Hall
We present the analysis of two epochs of archived HST WFPC2 observations of the Ursa Minor dwarf spheroidal galaxy. Reductions were performed using the HSTphot stellar photometry package. We report the detection of nine faint (MV >~ 0.0 mag) variable stars on the red giant branch which exhibit low-amplitude brightness fluctuations on ten-minute timescales with amplitudes ranging from 36 to 130 mmags. These variables account for 14% of all red giants that were observed. The timing of the observations does not yield sufficient information to determine whether the variability is periodic. If low-amplitude variability of red giants on ten-minute timescales can be verified and should their numbers prove to be ≥ 10% of all red giants in some ancient Population II stellar systems, then the length of star formation bursts in nearby dwarf spheroidal systems could be overestimated in short snapshot observations due to color-spreads caused by flickering red giants. I.U.R. 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.
[52.11] Chemical Abundances in Field AF stars
E. Schmidt (Carthage College and NOAO), J. W. Glaspey (NOAO), P. B. Stetson (Herzberg Institute of Astrophysics)
AAS 205th Meeting, 9-13 January 2005 Session 52 Stellar Atmospheres, Abundances and Opacities Poster, Tuesday, January 11, 2005, 9:20am-6:30pm, Exhibit Hall
High disperion spectra have been obtained with the GECKO spectrograph on the CFHT to determined chemical abundances. Stars were selected from lists of high-velocity stars compiled by Stetson. Preliminary results show that all are metal weak and have rotational velocities that range from nearly zero to over 40 km/s.
Abundances were determined by computing synthetic spectra using the SPECTRUM code provided by R. O. Gray (Appalachian State Univ.) for a range of abundances, effective temperatures (Teff) and surface gravities (log g). Equivalent widths were measured using the same IRAF tasks as were used on the observed stellar data. Teff and log g's were estimated from published uvby-Beta photometry. While the high resolution data allow precise measurements of parameters for the lines covered, additional spectra at moderate dispersion will be needed to measure a larger sample of lines for each chemical species.
E. Schmidt's work was funded by an NSF grant to NOAO for Research Experiences for Undergraduates.
[14.06] Stellar Variability in the Young, Metal Rich Open Cluster NGC 2301
C. VanOutryve (NOAO / UC Berkeley), S. B. Howell (WIYN / NOAO), J. L. Tonry (Inst. for Astronomy, U of Hawaii)
AAS 205th Meeting, 9-13 January 2005 Session 14 Variable Stars and Stellar Oscillations Poster, Monday, January 10, 2005, 9:20am-6:30pm, Exhibit Hall
Using an Orthogonal Transfer CCD camera (OPTIC), we observed the young, metal rich open cluster NCG 2301 over a 14 night period in Feb. 2004. Six adjacent fields centered on the cluster were observed in sequence each night with a field repeat cadence of about 12 minutes. Our photometric precision was near 1-2 mmag for the top 5 magnitudes of dynamic range of the detector, a vast improvement over normal CCD observations. Using a reduced chi-squared of greater than three as our determining variability statistic, we find that 56% of all our point sources are variable. Of these variables, 64% are periodic (at a 99% confidence level). Details on this variability in terms of stellar type, cluster location, etc. will be presented and discussed. Partial support of this research was provided by the NSF.
[54.09] Hubble's Variable 19 in the Asiago Photographic Plates
L.T. Laursen (Harvard-Smithsonian Center for Astrophysics), L.M. Macri (National Optical Astronomy Observatory)
AAS 205th Meeting, 9-13 January 2005 Session 54 Pulsating Stars: RR Lyraes, Miras, Cepheids, etc. Poster, Tuesday, January 11, 2005, 9:20am-6:30pm, Exhibit Hall
We present the results of a photometric study of Hubble's Variable 19 (V19) in scanned archival photographic plates from the Asiago Observatory. The plates cover the period from 1973 to 1984, for which photometry of V19 is unpublished. V19 was classified as a Cepheid with a period of 54.7 days and an intensity-weighted mean B magnitude of 19.59±.23 mag with a B amplitude of 1.1 mag by Hubble in his studies of M33. The recovery of V19 as part of the DIRECT project found the amplitude reduced to less than 0.1 mag and a mean B magnitude of 19.08±.05 mag. This study finds an amplitude of less than 0.1 mag and a mean B magnitude of 19.23±.1 mag for the time period covered by the plates.
There are also REU programs at Cerro Tololo Inter-American Observatory (CTIO) and at the National Solar Observatory at Sacramento Peak, NM. The National Science Foundation maintains a complete list of REU programs from around the country and in a wide variety of content areas, including astronomy.