A Search for Multi-Planet Systems Using the Hobby-Eberly Telescope (2009)
Wittenmyer, Robert A., Endl, Michael, Cochran, William D., Levison, Harold F., Henry, Gregory W.
Extrasolar multiple-planet systems provide valuable opportunities for testing theories of planet formation and evolution. The architectures of the known multiple-planet systems demonstrate a...
Discovery of a low-mass companion to the solar-type star TYC 2534-698-1 (2009)
Kane, Stephen R., Mahadevan, Suvrath, Cochran, William D., Street, Rachel A., Sivarani, Thirupathi, Henry, Gregory W., ...
Brown dwarfs and low-mass stellar companions are interesting objects to study since they occupy the mass region between deuterium and hydrogen burning. We report here the serendipitous discovery of a...
HD 91669B: a new brown dwarf candidate from the McDonald observatory planet search (2009)
Wittenmeyer, Robert A., Endl, Michael, Cochran, William D., Ramírez, Ivan, Reffert, Sabine, MacQueen, Phillip J., ...
HD 91669b: A New Brown Dwarf Candidate from the McDonald Observatory Planet Search (2008)
Wittenmyer, Robert A., Endl, Michael, Cochran, William D., Ramirez, Ivan, Reffert, Sabine, MacQueen, Phillip J., ...
We report the detection of a candidate brown dwarf orbiting the metal-rich K dwarf HD 91669, based on radial-velocity data from the McDonald Observatory Planet Search. HD 91669b is a substellar...
Discovery of a Low-Mass Companion to the Solar-Type Star TYC 2534-698-1 (2008)
Kane, Stephen R., Mahadevan, Suvrath, Cochran, William D., Street, Rachel A., Thirupathi, Sivarani, Henry, Gregory W., ...
Brown dwarfs and low-mass stellar companions are interesting objects to study since they occupy the mass region between deuterium and hydrogen burning. We report here the serendipitous discovery of a...
The Spin-Orbit Alignment of the HD17156 Transiting Eccentric Planetary System (2008)
Cochran, William D., Redfield, Seth, Endl, Michael, Cochran, Anita L.
We present high precision radial velocity observations of HD17156 during a transit of its eccentric Jovian planet. In these data, we detect the Rossiter-McLaughlin effect, which is an apparent...
Spitzer observations of the Hyades: Circumstellar debris disks at 625 Myr of age (2008)
Cieza, Lucas, Cochran, William D., Augereau, Jean-Charles
We use the Spitzer Space Telescope to search for infrared excess at 24, 70, and 160 micron due to debris disks around a sample of 45 FGK-type members of the Hyades cluster. We supplement our...
Redfield, Seth, Endl, Michael, Cochran, William D., Koesterke, Lars
We present the first ground-based detection of sodium absorption in the transmission spectrum of an extrasolar planet. Absorption due to the atmosphere of the extrasolar planet HD189733b is detected...
Artie Hatzes, William D. Cochran
The shape of the Ti I 6303.8 A spectral line of Aldebaran as measured by the line bisector was investigated using high signal-to-noise, high resolution data. The goal of this study was to understand...
in Comets 122P/1995 S1 (deVico) and C/1995 O1 (Hale-Bopp) (2007)
Anita L. Cochran, William D. Cochran, Edwin S. Barker, Mcdonald Observatory
Accepted for publication in Icarus We observed comets 122P/1995S1 (deVico) and C/1995O1 (Hale-Bopp) with high spectral resolving power in order to determine the ratio of N
In Spectra Of, Anita L. Cochran, William D. Cochran, Mcdonald Observatory
We report on high spectral resolution observations of comet C/1999S4 (LINEAR) obtained at McDonald Observatory in June and July 2000. We report unequivocal detections of the O ( D) metastable lines...
An m sin i = 24 Earth Mass Planetary Companion To The Nearby M Dwarf GJ 176 (2007)
Endl, Michael, Cochran, William D., Wittenmyer, Robert A., Boss, Alan P.
We report the detection of a planetary companion with a minimum mass of m sin i = 0.0771 M_Jup = 24.5 M_Earth to the nearby (d = 9.4 pc) M2.5V star GJ 176. The star was observed as part of our M...
Wittenmyer, Robert A., Endl, Michael, Cochran, William D., Levison, Harold F.
Long time coverage and high radial velocity precision have allowed for the discovery of additional objects in known planetary systems. Many of the extrasolar planets detected have highly eccentric...
A Planetary System Around HD 155358: The Lowest Metallicity Planet Host Star (2007)
Cochran, William D., Endl, Michael, Wittenmyer, Robert A., Bean, Jacob L.
We report the detection of two planetary mass companions to the solar-type star HD 155358. The two planets have orbital periods of 195.0 and 530.3 days, with eccentricities of 0.11 and 0.18. The...
The Extrasolar Planet epsilon Eridani b - Orbit and Mass (2006)
Benedict, G. Fritz, McArthur, Barbara E., Gatewood, George, Nelan, Edmund, Cochran, William D., Hatzes, Artie, ...
Hubble Space Telescope observations of the nearby (3.22 pc), K2 V star epsilon Eridani have been combined with ground-based astrometric and radial velocity data to determine the mass of its known...
Long-Period Objects in the Extrasolar Planetary Systems 47 UMa and 14 Her (2006)
Wittenmyer, Robert A., Endl, Michael, Cochran, William D.
The possible existence of additional long-period planetary-mass objects in the extrasolar planetary systems 47 UMa and 14 Her is investigated. We combine all available radial-velocity data on these...
Exploring The Frequency Of Close-In Jovian Planets Around M Dwarfs (2006)
Endl, Michael, Cochran, William D., Kuerster, Martin, Paulson, Diane B., Wittenmyer, Robert A., MacQueen, Phillip J., ...
We discuss our high precision radial velocity results of a sample of 90 M dwarfs observed with the Hobby-Eberly Telescope and the Harlan J. Smith 2.7 m Telescope at McDonald Observatory, as well as...
Ge, Jian, Van Eyken, Julian, Mahadevan, Suvrath, DeWitt, Curtis, Kane, Stephen R., Cohen, Roger, ...
We report the detection of the first extrasolar planet, ET-1 (HD 102195b), using the Exoplanet Tracker (ET), a new generation Doppler instrument. The planet orbits HD 102195, a young star with solar...
Detection Limits from the McDonald Observatory Planet Search Program (2006)
Wittenmyer, Robert A., Endl, Michael, Cochran, William D., Hatzes, Artie P., Walker, G. A. H., Yang, S. L. S., ...
Based on the long-term radial-velocity surveys carried out with the McDonald Observatory 2.7m Harlan J. Smith Telescope from 1988 to the present, we derive upper limits to long-period giant planet...
Determination Of The Orbit Of The Planetary Companion To The Metal Rich Star HD 45350 (2006)
Endl, Michael, Cochran, William D., Wittenmyer, Robert A., Hatzes, Artie P.
We present the precise radial velocity (RV) data for the metal-rich star HD 45350 collected with the Harlan J. Smith (HJS) 2.7 m telescope and the Hobby-Eberly Telescope (HET) at McDonald...
Exploring the frequency of close-in Jovian planets around M dwarfs (2006)
Endl, Michael, Cochran, William D., Kürster, Martin, Paulson, Diane B., Wittenmyer, Robert A., MacQueen, Phillip J., ...
We discuss our high-precision radial velocity results of a sample of 90 M dwarfs observed with the Hobby-Eberly Telescope and the Harlan J. Smith 2.7 m Telescope at McDonald Observatory, as well as...
The Extrasolar Planet e Eridani b: Orbit and mass (2006)
Benedict, G. Fritz, McArthur, Barbara E., Gatewood, George, Nelan, Edmund, Cochran, William D., Hatzes, Artie, ...
Hubble Space Telescope (HST) observations of the nearby (3.22 pc) K2 V star É Eridani have been combined with ground-based astrometric and radial velocity data to determine the mass of its known...
Jian Ge, Julian Van Eyken, Suvrath Mahadevan, Curtis Dewitt, Stephen R. Kane, Roger Cohen, ...
We report the detection of the first extrasolar planet, ET-1 (HD 102195b), using the Exoplanet Tracker (ET), a new-generation Doppler instrument. The planet orbits HD 102195, a young star with solar...
McArthur, Barbara E., Endl, Michael, Cochran, William D., Benedict, G. Fritz, Fischer, Debra A., Marcy, Geoffrey W., ...
We report the detection of the lowest mass extra-solar planet yet found around a Sun-like star - a planet with an \msini of only 14.21 $\pm$ 2.91 Earth masses in an extremely short period orbit...
HD 137510: An Oasis in the Brown Dwarf Desert (2004)
Endl, Michael, Hatzes, Artie P., Cochran, William D., McArthur, Barbara, Prieto, Carlos Allende, ...
Since the beginning of precise Doppler surveys, which have had stunning success in detecting extrasolar planetary companions, one surprising enigma has emerged: the relative paucity of spectroscopic...
The ESO radial velocity program. Status und results (2004)
Kürster, Martin, Endl, Michael, Els, Sebastian, Hatzes, Artie P., Cochran, William D., Rouesnel, Frédéric, ...
Are there Jupiters in the α Centauri system (2004)
Endl, Michael, Kürster, Martin, Els, Sebastian, Hatzes, Artie P., Cochran, William D., Rouesnel, Frédéric, ...
A Planetary Companion to gamma Cephei A (2003)
Hatzes, Artie P., Cochran, William D., Endl, Michael, McArthur, Barbara, Paulson, Diane B., Walker, Gordon A. H., ...
We report on the detection of a planetary companion in orbit around the primary star of the binary system $\gamma$ Cephei. High precision radial velocity measurements using 4 independent data sets...
Searching for Planets in the Hyades IV: Differential Abundance Analysis of Hyades Dwarfs (2003)
Paulson, Diane B., Sneden, Christopher, Cochran, William D.
We present a differential abundance analysis of Hyades F-K dwarfs in search for evidence of stellar enrichment from accreted hydrogen deficient disk material. Metallicites and relative abundance...
Diane B. Paulson, Steven H. Saar, William D. Cochran, Gregory W. Henry
We have been using the Keck I High Resolution Spectrograph to search for planetary companions in the Hyades cluster. We selected four stars from this sample that showed significant radial velocity...
Extrasolar Terrestrial Planets: Can We Detect Them Already? (2002)
Endl, Michael, Kuerster, Martin, Rouesnel, Frederic, Els, Sebastian, Hatzes, Artie P., Cochran, William D.
With the example of Proxima Centauri we discuss the feasibility of detecting terrestrial planets (1 to a few M_Earth) using the high precision radial velocity (RV) technique. If a very high RV...
Searching for Planets in the Hyades. I. The Keck Radial Velocity Survey (2002)
Cochran, William D., Hatzes, Artie P., Paulson, Diane B.
We describe a high-precision radial velocity search for jovian-mass companions to main sequence stars in the Hyades star cluster. The Hyades provides an extremely well controlled sample of stars of...
Searching for Planets in the Hyades II: Some Implications of Stellar Magnetic Activity (2002)
Paulson, Diane B., Saar, Steven H., Cochran, William D., Hatzes, Artie P.
The Hyades constitute a homogeneous sample of stars ideal for investigating the dependence of planet formation on the mass of the central star. Due to their youth, Hyades members are much more...
A High Spectral Resolution Atlas of Comet 122P/de Vico (2002)
Cochran, Anita L., Cochran, William D.
On 3 and 4 October, 1995, we obtained high spectral resolving power (R=\lambda/\Delta\lambda = 60,000) observations of comet 122P/de Vico using the 2DCoude cross-dispersed echelle spectrograph on the...
Observations of O (1S) and O (1D) in Spectra of C/1999 S4 (LINEAR) (2001)
Cochran, Anita L., Cochran, William D.
We report on high spectral resolution observations of comet C/1999 S4 (LINEAR) obtained at McDonald Observatory in June and July 2000. We report unequivocal detections of the O (1S) and O (1D)...
Evidence for a Long-period Planet Orbiting Epsilon Eridani (2000)
Hatzes, Artie P., Cochran, William D., McArthur, Barbara, Baliunas, Sallie L., Walker, Gordon A. H., Campbell, Bruce, ...
High precision radial velocity (RV) measurements spanning the years 1980.8--2000.0 are presented for the nearby (3.22 pc) K2 V star $\epsilon$ Eri. These data, which represent a combination of six...
N$_2^+$ and CO$^+$ in Comets 122P/1995 S1 (deVico) and C/1995 O1 (Hale-Bopp) (2000)
Cochran, Anita L., Cochran, William D., Barker, Edwin S.
We observed comets 122P/1995\,S1 (deVico) and C/1995\,O1 (Hale-Bopp) with high spectral resolving power in order to determine the ratio of N$_2^+$/CO$^+$ in their comae. While we clearly detected the...
Extrasolar Planets Around Main Sequence Stars (1999)
Planets Iv, Ed. V. Mannings, A. Boss, S. Russell, Geoffrey W. Marcy, William D. Cochran, ...
INTRODUCTION Our Sun is a very common and ordinary star. There is really nothing to distinguish it from a myriad of other similar stars in this region of the Galaxy. Yet, the Sun possesses a...
Further evidence for the planet around 51 Pegasi (1997)
Hatzes, Artie P., Cochran, William D., Bakker, Eric J.
The discovery of the planet around the solar-type star 51 Pegasi marked a watershed in the search for extrasolar planets. Since then seven other solar-type stars have been discovered, of which...
Hatzes, Artie P., Cochran, William D.
The shape of the Ti I 6303.8 A spectral line of Aldebaran as measured by the line bisector was investigated using high signal-to-noise, high resolution data. The goal of this study was to understand...
Hatzes, Artie P., Cochran, William D.
An analysis is made of the spectral line shapes of tau Bootis using high resolution (0.026 A) and high signal-to-noise (S/N~400) data in an effort to confirm the planet hypothesis for this star....
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