Physical Sciences and Mathematics | Open Access Articles

On The Search For Transits Of The Planets Orbiting Gliese 876, Paul D. Shankland, Eugenio J. Rivera, Gregory Laughlin, D. L. Blank, A. Price, B. Gary, R. Bissinger, Frederick Ringwald, G. White, Gregory W. Henry, Padric Mcgee, Aaron S. Wolf, Brad Carter, S. Lee, James Biggs, Berto Monard, Michael C. B. Ashley

Information Systems and Engineering Management Research Publications

We report the results of a globally coordinated photometric campaign to search for transits by the P ~ 30 day and P ~ 60 day outer planets of the three-planet system orbiting the nearby M dwarf Gl 876. These two planets experience strong mutual perturbations, which necessitate the use of a dynamical (four-body) model to compute transit ephemerides for the system. Our photometric data have been collected from published archival sources, as well as from our photometric campaigns that were targeted to specific transit predictions. Our analysis indicates that transits by planet c (P ~ 30 days) do not currently …

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An Eccentric Hot Jupiter Orbiting The Subgiant Hd 185269, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Gregory W. Henry, Jason T. Wright, Howard Isaacson, Chris Mccarthy

Information Systems and Engineering Management Research Publications

We report the detection of a Jupiter-mass planet in a 6.838 day orbit around the 1.28 M☉ subgiant HD 185269. The eccentricity of HD 185269b (e = 0.30) is unusually large compared to other planets within 0.1 AU of their stars. Photometric observations demonstrate that the star is constant to ±0.0001 mag on the radial velocity period, strengthening our interpretation of a planetary companion. This planet was detected as part of our radial velocity survey of evolved stars located on the subgiant branch of the H-R diagram—also known as the Hertzsprung gap. These stars, which have masses between 1.2 and …

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Measurement Of The Spin-Orbit Alignment In The Exoplanetary System Hd 189733, Joshua N. Winn, John Asher Johnson, Geoffrey W. Marcy, R. Paul Butler, Steve Vogt, Gregory W. Henry, Anna Roussanova, Matthew J. Holman, Keigo Enya, Norio Narita, Yasushi Suto, Edwin L. Turner

Information Systems and Engineering Management Research Publications

We present spectroscopy of a transit of the exoplanet HD 189733b. By modeling the Rossiter-McLaughlin effect (the anomalous Doppler shift due to the partial eclipse of the rotating stellar surface), we find the angle between the sky projections of the stellar spin axis and orbit normal to be λ = -1fdg4 ± 1fdg1. This is the third case of a "hot Jupiter" for which λ has been measured. In all three cases λ is small, ruling out random orientations with 99.96% confidence, and suggesting that the inward migration of hot Jupiters generally preserves spin-orbit alignment.

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Hd 71636, A Newly Discovered Eclipsing Binary, Gregory W. Henry, Francis C. Fekel, James R. Sowell, Joel S. Gearhart

Information Systems and Engineering Management Research Publications

Our differential BV photometric observations, acquired with an automated telescope at Fairborn Observatory, show that HD 71636 is an eclipsing binary. From follow-up red-wavelength spectroscopic observations we classify the primary and secondary as an F2 dwarf and an F5 dwarf, respectively. The system has a period of 5.01329 days and a circular orbit. We used the Wilson-Devinney program to simultaneously solve our BV light curves and radial velocities and determined a number of fundamental properties of the system. Comparison with evolutionary tracks indicates that both stars are well ensconced on the main sequence. The age of the system is about …

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Hd 131861, A Double-Line Spectroscopic Triple System, Francis C. Fekel, Gregory W. Henry, David J. Barlow, Dimitri Pourbaix

Information Systems and Engineering Management Research Publications

Our red-wavelength spectroscopic observations of HD 131861, a previously known single-line multiple system, span 20 years. Now lines of two components, the short-period F5 V primary and G8 V secondary, have been detected. The inner orbit is circular with a period of 3.5507439 days, while the outer orbit of the system has a period of 1642 days or 4.496 yr and a relatively low eccentricity of 0.10. Analysis of the Hipparcos data produces a well-determined astrometric orbit for the long-period system that has an inclination of 52°. Our photometric observations show shallow primary and secondary eclipses of the short-period pair, …

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The First Extrasolar Planet Discovered With A New-Generation High-Throughput Doppler Instrument, Jian Ge, Julian C. Van Eyken, Suvrath Mahadevan, Curtis Dewitt, Stephen R. Kane, Roger Cohen, Andrew Vanden Heuvel, Scott W. Fleming, Pengcheng Guo, Gregory W. Henry, Donald P. Schneider, Lawrence W. Ramsey, Robert A. Wittenmyer, Michael Endl, William D. Cochran, Eric B. Ford, Eduardo L. Martín, Garik Israelian, Jeff A. Valenti, David Montes

Information Systems and Engineering Management Research Publications

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 metallicity that may be part of the local association. The planet imparts radial velocity variability to the star with a semiamplitude of 63.4 ± 2.0 m s-1 and a period of 4.11 days. The planetary minimum mass (m sin i) is 0.488MJ ± 0.015MJ. The planet was initially detected in the spring of 2005 with the Kitt Peak National Observatory (KPNO) 0.9 m coudé feed telescope. The detection was …

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Hr 1613: A Slowly Rotating A Dwarf Spectroscopic Binary With Solar Abundances, Francis C. Fekel, Michael H. Williamson, Christiane Buggs, Gerald Onuoha, Brittany Smith

Information Systems and Engineering Management Research Publications

From two sets of radial velocities we have obtained the orbital elements of HR 1613. This single-lined binary has an orbital period of 8.11128 days and a nearly circular orbit. The primary has an A9 V spectral type and a v sin i value of 11 km s-1, while the unseen secondary is likely a K or M dwarf. Spectral classifications and spectrum synthesis analysis indicate that the abundances of the primary are normal. We reject the possibility that the primary of HR 1613 is seen nearly pole-on and instead argue that its rotational inclination is at least 20°, resulting …

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The N2k Consortium. Vi. Doppler Shifts Without Templates And Three New Short-Period Planets, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Gregory Laughlin, R. Paul Butler, Gregory W. Henry, Jeff A. Valenti, Eric B. Ford, Steve Vogt, Jason T. Wright

Information Systems and Engineering Management Research Publications

We present a modification to the iodine cell Doppler technique that eliminates the need for an observed stellar template spectrum. For a given target star, we iterate toward a synthetic template spectrum beginning with an existing template of a similar star. We then perturb the shape of this first-guess template to match the program observation of the target star taken through an iodine cell. The elimination of a separate template observation saves valuable telescope time, a feature that is ideally suited for the quick-look strategy employed by the "Next 2000 Stars" (N2K) planet search program. Tests using Keck HIRES (High …

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New Precision Orbits Of Bright Double-Lined Spectroscopic Binaries. I. Rr Lyncis, 12 Bootis, And Hr 6169, Jocelyn Tomkin, Francis C. Fekel

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Radial velocities from the 2.1 m telescope at McDonald Observatory supplemented with radial velocities from the coudé feed telescope at Kitt Peak National Observatory provide new precise orbits for the double-lined spectroscopic binaries RR Lyn (A3/A8/A6), 12 Boo (F8 IV), and HR 6169 (A2 V). We derive orbital dimensions (a1 sin i and a2 sin i) and minimum masses (m1 i and m2 i) with accuracies of 0.06%-0.9%. The three systems, which have V magnitudes of 5.53, 4.82, and 6.42, respectively, are all sufficiently bright that they are easily within the grasp of modern optical interferometers and so afford the …

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Infrared Spectroscopy Of Symbiotic Stars. Iv. V2116 Ophiuchi/Gx 1+4, The Neutron Star Symbiotic, Kenneth H. Hinkle, Francis C. Fekel, Richard R. Joyce, Peter R. Wood, Verne V. Smith, Thomas Lebzelter

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We have computed, using 17 infrared radial velocities, the first set of orbital elements for the M giant in the symbiotic binary V2116 Ophiuchi. The giant's companion is a neutron star, the bright X-ray source GX 1+4. We rule out the previously proposed period of 304 days and instead find an orbital period of 1161 days, by far the longest of any known X-ray binary. The orbit has a modest eccentricity of 0.10, with an orbital circularization time of ≲5 × 106 yr. The large mass function of the orbit significantly restricts the mass of the M giant. Adopting a …

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Rotational And Cyclical Variability In Γ Cassiopeia, Myron A. Smith, Gregory W. Henry, Ethan Vishniac

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γ Cas is an unusual classical Be star for which the optical-band and hard X-ray fluxes vary on a variety of timescales. We report results of a 9 yr monitoring effort on this star with a robotic ground-based (APT) telescope in the B, V filter system, as well as simultaneous observations in 2004 November with this instrument and the RXTE. Our observations disclosed no correlated optical response to the rapid X-ray flares in this star, nor did the star show any sustained flux changes any time during two monitored nights in either wavelength regime. Consistent with an earlier study by …

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Spectroscopy And Photometry Of The Double-Lined Binary Hd 149420, Francis C. Fekel, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We have used new spectroscopic and photometric observations of HD 149420 to obtain an improved orbital element solution and determine some basic properties of the system. This double-lined binary has an orbital period of 3.39430 days, a circular orbit, and a mass ratio of 0.52. The primary is somewhat evolved, with an A9 IV spectral type, while the secondary is estimated to be an F5: dwarf. The secondary may be synchronously rotating, but the primary is rotating substantially slower than its synchronous velocity. Our photometric observations confirm the light variability and period found by Hipparcos. We determine a photometric period …

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The N2k Consortium. Iii. Short-Period Planets Orbiting Hd 149143 And Hd 109749, Debra A. Fischer, Gregory Laughlin, Geoffrey W. Marcy, R. Paul Butler, Steve S. Vogt, John A. Johnson, Gregory W. Henry, Chris Mccarthy, Mark Ammons, Sarah Robinson, Jay Strader, Jeff A. Valenti, Peter R. Mccullough, David Charbonneau, Joshua Haislip, Heather Knutson, Daniel E. Reichart, Padric Mcgee, Berto Monard, Jason T. Wright, Shigeru Ida, Bun'ei Sato, Dante Minniti

Information Systems and Engineering Management Research Publications

We report the detection of two short-period planets discovered at Keck Observatory. HD 149143 is a metal-rich G0 IV star with a planet of M sin i = 1.33MJ and an orbital radius of 0.053 AU. The best-fit Keplerian model has an orbital period, P = 4.072 days, semivelocity amplitude, K = 149.6 m s-1, and eccentricity, e = 0.016 ± 0.01. The host star is chromospherically inactive and metal-rich, with [Fe/H] = 0.26. Based on the Teff and stellar luminosity, we derive a stellar radius of 1.49 R☉. Photometric observations of HD 149143 were carried out using the automated …

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Information Systems and Engineering Management Research Publications

An Eccentric Hot Jupiter Orbiting The Subgiant Hd 185269, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Gregory W. Henry, Jason T. Wright, Howard Isaacson, Chris Mccarthy

Information Systems and Engineering Management Research Publications

Measurement Of The Spin-Orbit Alignment In The Exoplanetary System Hd 189733, Joshua N. Winn, John Asher Johnson, Geoffrey W. Marcy, R. Paul Butler, Steve Vogt, Gregory W. Henry, Anna Roussanova, Matthew J. Holman, Keigo Enya, Norio Narita, Yasushi Suto, Edwin L. Turner

Information Systems and Engineering Management Research Publications

Hd 71636, A Newly Discovered Eclipsing Binary, Gregory W. Henry, Francis C. Fekel, James R. Sowell, Joel S. Gearhart

Information Systems and Engineering Management Research Publications

Hd 131861, A Double-Line Spectroscopic Triple System, Francis C. Fekel, Gregory W. Henry, David J. Barlow, Dimitri Pourbaix

Information Systems and Engineering Management Research Publications

Information Systems and Engineering Management Research Publications

Hr 1613: A Slowly Rotating A Dwarf Spectroscopic Binary With Solar Abundances, Francis C. Fekel, Michael H. Williamson, Christiane Buggs, Gerald Onuoha, Brittany Smith

Information Systems and Engineering Management Research Publications

The N2k Consortium. Vi. Doppler Shifts Without Templates And Three New Short-Period Planets, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Gregory Laughlin, R. Paul Butler, Gregory W. Henry, Jeff A. Valenti, Eric B. Ford, Steve Vogt, Jason T. Wright

Information Systems and Engineering Management Research Publications

New Precision Orbits Of Bright Double-Lined Spectroscopic Binaries. I. Rr Lyncis, 12 Bootis, And Hr 6169, Jocelyn Tomkin, Francis C. Fekel

Information Systems and Engineering Management Research Publications

Infrared Spectroscopy Of Symbiotic Stars. Iv. V2116 Ophiuchi/Gx 1+4, The Neutron Star Symbiotic, Kenneth H. Hinkle, Francis C. Fekel, Richard R. Joyce, Peter R. Wood, Verne V. Smith, Thomas Lebzelter

Information Systems and Engineering Management Research Publications

Rotational And Cyclical Variability In Γ Cassiopeia, Myron A. Smith, Gregory W. Henry, Ethan Vishniac

Information Systems and Engineering Management Research Publications

Spectroscopy And Photometry Of The Double-Lined Binary Hd 149420, Francis C. Fekel, Gregory W. Henry

Information Systems and Engineering Management Research Publications

Information Systems and Engineering Management Research Publications