Browsing by Department "McDonald Observatory"

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    • A 12 Minute Orbital Period Detached White Dwarf Eclipsing Binary 

      Brown, Warren R.; Kilic, Mukremin; Hermes, J. J.; Prieto, Carlos Allende; Kenyon, Scott J.; Winget, D. E. (2011-08)
      We have discovered a detached pair of white dwarfs (WDs) with a 12.75 minute orbital period and a 1315 km s(-1) radial velocity amplitude. We measure the full orbital parameters of the system using its light curve, which ...

    • 18 Sco: A Solar Twin Rich In Refractory And Neutron-Capture Elements. Implications For Chemical Tagging 

      Melendez, Jorge; Ramirez, Ivan; Karakas, Amanda I.; Yong, David; Monroe, TalaWanda R.; Bedell, Megan; Bergemann, Maria; Asplund, Martin; Maia, Marcelo Tucci; Bean, Jacob; do Nascimento, Jose-Dias; Bazot, Michael; Alves-Brito, Alan; Freitas, Fabricio C.; Castro, Matthieu (2014-08)
      We study with unprecedented detail the chemical composition and stellar parameters of the solar twin 18 Sco in a strictly differential sense relative to the Sun. Our study is mainly based on high-resolution (R similar to ...

    • 400 Years of Sunspots 

      University of Texas at Austin; McDonald Observatory (McDonald Observatory, 2011)

    • 50th Anniversary Lecture: Founding & History of McDonald Observatory 

      University of Texas at Austin; McDonald Observatory (1989)

    • 75th Anniversary Lecture: The Frontier & McDonald Observatory 

      University of Texas at Austin; McDonald Observatory (McDonald Observatory, 2013-10-19)

    • Abundances Of C, N, Sr, And Ba On The Red Giant Branch Of Omega Centauri 

      Stanford, Laura M.; Da Costa, G. S.; Norris, John E. (2010-05)
      Abundances relative to iron for carbon, nitrogen, strontium, and barium are presented for 33 stars on the red giant branch (RGB) of the globular cluster omega Centauri. They are based on intermediate-resolution spectroscopic ...

    • The ACS Survey Of Galactic Globular Clusters. III. The Double Subgiant Branch Of NGC 1851 

      Milone, A. P.; Bedin, L. R.; Piotto, G.; Anderson, J.; King, I. R.; Sarajedini, A.; Dotter, A.; Chaboyer, B.; Marin-Franch, A.; Majewski, S.; Aparicio, A.; Hempel, M.; Paust, N. E. Q.; Reid, I. N.; Rosenberg, A.; Siegel, M. (2008-01)
      Photometry with the Hubble Space Telescope Advanced Camera for Surveys (HSTACS) reveals that the subgiant branch (SGB) of the globular cluster NGC 1851 splits into two well-defined branches. If the split is due only to an ...

    • The ACS Survey Of Galactic Globular Clusters. VII. Relative Ages 

      Marin-Franch, Antonio; Aparicio, Antonio; Piotto, Giampaolo; Rosenberg, Alfred; Chaboyer, Brian; Sarajedini, Ata; Siegel, Michael; Anderson, Jay; Bedin, Luigi R.; Dotter, Aaron; Hempel, Maren; King, Ivan; Majewski, Steven; Milone, Antonino P.; Paust, Nathaniel; Reid, I. Neill (2009-04)
      The ACS Survey of Galactic globular clusters is a Hubble Space Telescope Treasury program designed to provide a new large, deep, and homogeneous photometric database. Based on observations from this program, we have measured ...

    • Age of the Milky Way 

      University of Texas at Austin; McDonald Observatory (McDonald Observatory, undated)

    • The Apache Point Observatory Galactic Evolution Experiment: First Detection of High-Velocity Milky Way Bar Stars 

      Nidever, David L.; Zasowski, Gail; Majewski, Steven R.; Bird, Jonathan; Robin, Annie C.; Martinez-Valpuesta, Inma; Beaton, Rachael L.; Schoenrich, Ralph; Schultheis, Mathias; Wilson, John C.; Skrutskie, Michael F.; O'Connell, Robert W.; Shetrone, Matthew; Schiavon, Ricardo P.; Johnson, Jennifer A.; Weiner, Benjamin; Gerhard, Ortwin; Schneider, Donald P.; Prieto, Carlos Allende; Sellgren, Kris; Bizyaev, Dmitry; Brewington, Howard; Brinkmann, Jon; Eisenstein, Daniel J.; Frinchaboy, Peter M.; Perez, Ana Elia Garcia; Holtzman, Jon; Hearty, Fred R.; Malanushenko, Elena; Malanushenko, Viktor; Muna, Demitri; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey; Snedden, Stephanie; Weaver, Benjamin A. (2012-08)
      Commissioning observations with the Apache Point Observatory Galactic Evolution Experiment (APOGEE), part of the Sloan Digital Sky Survey III, have produced radial velocities (RVs) for similar to 4700 K/M-giant stars in ...

    • The APOGEE Red-Clump Catalog: Precise Distances, Velocities, And High-Resolution Elemental Abundances Over A Large Area Of The Milky Way's Disk 

      Bovy, Jo; Nidever, David L.; Rix, Hans-Walter; Girardi, Leo; Zasowski, Gail; Chojnowski, S. Drew; Holtzman, Jon; Epstein, Courtney; Frinchaboy, Peter M.; Hayden, Michael R.; Rodrigues, Thaise S.; Majewski, Steven R.; Johnson, Jennifer A.; Pinsonneault, Marc H.; Stello, Dennis; Prieto, Carlos Allende; Andrews, Brett; Basu, Sarbani; Beers, Timothy C.; Bizyaev, Dmitry; Burton, Adam; Chaplin, William J.; Cunha, Katia; Elsworth, Yvonne; Garcia, Rafael A.; Garcia-Hernandez, Domingo A.; Garcia Perez, Ana E.; Hearty, Fred R.; Hekker, Saskia; Kallinger, Thomas; Kinemuchi, Karen; Koesterke, Lars; Meszaros, Szabolcs; Mosser, Benoit; O'Connell, Robert W.; Oravetz, Daniel; Pan, Kaike; Robin, Annie C.; Schiavon, Ricardo P.; Schneider, Donald P.; Schultheis, Mathias; Serenelli, Aldo; Shetrone, Matthew; Aguirre, Victor Silva; Simmons, Audrey; Skrutskie, Michael; Smith, Verne V.; Stassun, Keivan; Weinberg, David H.; Wilson, John C.; Zamora, Olga (2014-08)
      The Sloan Digital Sky Survey III's Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a high-resolution near-infrared spectroscopic survey covering all of the major components of the Galaxy, including the ...

    • The Apokasc Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields 

      Nidever, David L.; Zasowski, Gail; Majewski, Steven R.; Bird, Jonathan; Robin, Annie C.; Martinez-Valpuesta, Inma; Beaton, Rachael L.; Schoenrich, Ralph; Schultheis, Mathias; Wilson, John C.; Skrutskie, Michael F.; O'Connell, Robert W.; Shetrone, Matthew; Schiavon, Ricardo P.; Johnson, Jennifer A.; Weiner, Benjamin; Gerhard, Ortwin; Schneider, Donald P.; Prieto, Carlos Allende; Sellgren, Kris; Bizyaev, Dmitry; Brewington, Howard; Brinkmann, Jon; Eisenstein, Daniel J.; Frinchaboy, Peter M.; Perez, Ana Elia Garcia; Holtzman, Jon; Hearty, Fred R.; Malanushenko, Elena; Malanushenko, Viktor; Muna, Demitri; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey; Snedden, Stephanie; Weaver, Benjamin A. (2014-12)
      We present the first APOKASC catalog of spectroscopic and asteroseismic properties of 1916 red giants observed in the Kepler fields. The spectroscopic parameters provided from the Apache Point Observatory Galactic Evolution ...

    • Are C-60 Molecules Detectable In Circumstellar Shells Of R Coronae Borealis Stars? 

      Garcia-Hernandez, D. Anibal; Rao, N. Kameswara; Lambert, David L. (2011-03)
      The hydrogen-poor, helium-rich, and carbon-rich character of the gas around R Coronae Borealis (RCB) stars has been suggested to be a site for formation of C-60 molecules. This suggestion is not supported by observations ...

    • Asteroseismic Determination Of Obliquities Of The Exoplanet Systems Kepler-50 And Kepler-65 

      Chaplin, W. J.; Sanchis-Ojeda, R.; Campante, T. L.; Handberg, R.; Stello, D.; Winn, Joshua N.; Basu, S.; Christensen-Dalsgaard, J.; Davies, G. R.; Metcalfe, T. S.; Buchhave, Lars A.; Fischer, Debra A.; Bedding, T. R.; Cochran, William D.; Elsworth, Y.; Gilliland, R. L.; Hekker, S.; Huber, Daniel; Isaacson, Howard; Karoff, C.; Kawaler, Steven D.; Kjeldsen, H.; Latham, D. W.; Lund, M. N.; Lundkvist, M.; Marcy, Geoffrey W.; Miglio, A.; Barclay, Thomas; Lissauer, J. J. (2013-04)
      Results on the obliquity of exoplanet host stars-the angle between the stellar spin axis and the planetary orbital axis-provide important diagnostic information for theories describing planetary formation. Here we present ...

    • Astro Madness 

      University of Texas at Austin; McDonald Observatory (McDonald Observatory, undated)

    • Astrometry, Radial Velocity, And Photometry: The Hd 128311 System Remixed With Data From Hst, Het, And Apt 

      McArthur, Barbara E.; Benedict, G. Fritz; Henry, Gregory W.; Hatzes, Artie; Cochran, William D.; Harrison, Thomas E.; Johns-Krull, Chris; Nelan, Ed (2014-11)
      We have used high-cadence radial velocity measurements from the Hobby-Eberly Telescope with published velocities from the Lick 3 m Shane Telescope, combined with astrometric data from the Hubble Space Telescope (HST) Fine ...

    • Black Hole Mass And Eddington Ratio Distribution Functions Of X-Ray-Selected Broad-Line AGNs At Z Similar To 1.4 In The Subaru XMM-Newton Deep Field 

      Nobuta, K.; Akiyama, M.; Ueda, Y.; Watson, M. G.; Silverman, J.; Hiroi, K.; Ohta, K.; Iwamuro, F.; Yabe, K.; Tamura, N.; Moritani, Y.; Sumiyoshi, M.; Takato, N.; Kimura, M.; Maihara, T.; Dalton, G.; Lewis, I.; Bonfield, D.; Lee, H.; Curtis-Lake, E.; Macaulay, E.; Clarke, F.; Sekiguchi, K.; Simpson, C.; Croom, S.; Ouchi, Masami; Hanami, H.; Yamada, T. (2012-12)
      In order to investigate the growth of supermassive black holes (SMBHs), we construct the black hole mass function (BHMF) and Eddington ratio distribution function (ERDF) of X-ray-selected broad-line active galactic nuclei ...

    • Calibrating The Cepheid Period-Luminosity Relation From The Infrared Surface Brightness Technique I. The P-Factor, The Milky Way Relations, And A Universal K-Band Relation 

      Storm, Jesper; Gieren, Wolfgang; Fouque, Pascal; Barnes, Thomas G.; Pietrzynski, G.; Nardetto, Nicolas; Weber, M.; Granzer, T.; Strassmeier, K. G. (2011-10)
      Aims. We determine period-luminosity relations for Milky Way Cepheids in the optical and near-IR bands. These relations can be used directly as reference for extra-galactic distance determination to Cepheid populations ...

    • Calibrating The Cepheid Period-Luminosity Relation From The Infrared Surface Brightness Technique II. The Effect Of Metallicity And The Distance To The LMC 

      Storm, Jesper; Gieren, Wolfgang; Fouque, Pascal; Barnes, Thomas G.; Soszynski, I.; Pietrzynski, G.; Nardetto, Nicolas; Queloz, D. (2011-10)
      Context. The extragalactic distance scale builds directly on the Cepheid period-luminosity (PL) relation as delineated by the sample of Cepheids in the Large Magellanic Cloud (LMC). However, the LMC is a dwarf irregular ...

    • Calibrations Of Atmospheric Parameters Obtained From The First Year Of Sdss-III APOGEE Observations 

      Meszaros, S.; Holtzman, J.; Perez, A. E. Garcia; Prieto, C. Allende; Schiavon, R. P.; Basu, S.; Bizyaev, D.; Chaplin, W. J.; Chojnowski, S. D.; Cunha, K.; Elsworth, Y.; Epstein, C.; Frinchaboy, P. M.; Garcia, R. A.; Hearty, F. R.; Hekker, S.; Johnson, J. A.; Kallinger, T.; Koesterke, L.; Majewski, S. R.; Martell, S. L.; Nidever, D.; Pinsonneault, M. H.; O'Connell, J.; Shetrone, M.; Smith, V. V.; Wilson, J. C.; Zasowski, G. (2013-11)
      The Sloan Digital Sky Survey III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a three-year survey that is collecting 105 high-resolution spectra in the near-IR across multiple Galactic ...