Physical Sciences and Mathematics Commons^™

The Nasa-Uc Eta-Earth Program. Ii. A Planet Orbiting Hd 156668 With A Minimum Mass Of Four Earth Masses*, Andrew W. Howard, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Jason T. Wright, Gregory W. Henry, Howard Isaacson, Jeff A. Valenti, Jay Anderson, Nikolai Piskunov

Information Systems and Engineering Management Research Publications

We report the discovery of HD 156668 b, an extrasolar planet with a minimum mass of MPsin i = 4.15 M⊕. This planet was discovered through Keplerian modeling of precise radial velocities from Keck-HIRES and is the second super-Earth to emerge from the NASA-UC Eta-Earth Survey. The best-fit orbit is consistent with circular and has a period of P = 4.6455 days. The Doppler semi-amplitude of this planet, K = 1.89 m s−1, is among the lowest ever detected, on par with the detection of GJ 581 e using HARPS. A longer period (P ≈ 2.3 years), low-amplitude signal of …

Transit Spectrophotometry Of The Exoplanet Hd 189733b Ii. New Spitzer Observations At 3.6 Μm, Jean-Michel Désert, David K. Sing, Alfred Vidal-Madjar, Guillaume Hébrard, David Ehrenreich, Alain Lecavelier Des Etangs, Vivien Parmentier, Roger Ferlet, Gregory W. Henry

Information Systems and Engineering Management Research Publications

Context. We present a new primary transit observation of the hot-jupiter HD 189733b, obtained at 3.6 μm with the Infrared Array Camera (IRAC) onboard the Spitzer Space Telescope. Previous measurements at 3.6 microns suffered from strong systematics, and conclusions could hardly be obtained with confidence on the water detection by comparison of the 3.6 and 5.8 microns observations.

Aims. We aim at constraining the atmospheric structure and composition of the planet and improving previously derived parameters.

Methods. We use a high-S/NSpitzer photometric transit light curve to improve the precision of the near infrared radius of …

Retired A Stars And Their Companions. Vi. A Pair Of Interacting Exoplanet Pairs Around The Subgiants 24 Sextanis And Hd 200964*, John Asher Johnson, Matthew J. Payne, Andrew W. Howard, Kelsey I. Clubb, Eric B. Ford, Brendan P. Bowler, Gregory W. Henry, Debra A. Fischer, Geoffrey W. Marcy, John M. Brewer, Christian Schwab, Sabine Reffert, Thomas B. Lowe

Information Systems and Engineering Management Research Publications

We report radial velocity (RV) measurements of the G-type subgiants 24 Sextanis (= HD 90043) and HD 200964. Both are massive, evolved stars that exhibit periodic variations due to the presence of a pair of Jovian planets. Photometric monitoring with the T12 0.80 m APT at Fairborn Observatory demonstrates both stars to be constant in brightness to ⩽0.002 mag, thus strengthening the planetary interpretation of the RV variations. Based on our dynamical analysis of the RV time series, 24 Sex b, c have orbital periods of 452.8 days and 883.0 days, corresponding to semimajor axes 1.333 AU and 2.08 AU, …

The Phases Differential Astrometry Data Archive. Ii. Updated Binary Star Orbits And A Long Period Eclipsing Binary, Matthew W. Muterspaugh, William I. Hartkopf, Benjamin F. Lane, Julia O'Connell, Michael Williamson, Shrinivas R. Kulkarni, Maciej Konacki, Bernard F. Burke, Mark M. Colavita, Michael Shao, Sloane J. Wiktorowicz

Information Systems and Engineering Management Research Publications

Differential astrometry measurements from the Palomar High-precision Astrometric Search for Exoplanet Systems have been combined with lower precision single-aperture measurements covering a much longer timespan (from eyepiece measurements, speckle interferometry, and adaptive optics) to determine improved visual orbits for 20 binary stars. In some cases, radial velocity observations exist to constrain the full three-dimensional orbit and determine component masses. The visual orbit of one of these binaries—α Com (HD 114378)—shows that the system is likely to have eclipses, despite its very long period of 26 years. The next eclipse is predicted to be within a week of 2015 January 24.

The Phases Differential Astrometry Data Archive. V. Candidate Substellar Companions To Binary Systems, Matthew W. Muterspaugh, Benjamin F. Lane, Shrinivas R. Kulkarni, Maciej Konacki, Bernard F. Burke, Mark M. Colavita, Michael Shao, William I. Hartkopf, Alan P. Boss, Michael Williamson

Information Systems and Engineering Management Research Publications

The Palomar High-precision Astrometric Search for Exoplanet Systems monitored 51 subarcsecond binary systems to evaluate whether tertiary companions as small as Jovian planets orbited either the primary or secondary stars, perturbing their otherwise smooth Keplerian motions. Six binaries are presented that show evidence of substellar companions orbiting either the primary or secondary star. Of these six systems, the likelihoods of two of the detected perturbations to represent real objects are considered to be "high confidence," while the remaining four systems are less certain and will require continued observations for confirmation.

The Phases Differential Astrometry Data Archive. Iv. The Triple Star Systems 63 Gem A And Hr 2896, Matthew W. Muterspaugh, Francis C. Fekel, Benjamin F. Lane, William I. Hartkopf, Shrinivas R. Kulkarni, Maciej Konacki, Bernard F. Burke, Mark M. Colavita, Michael Shao, Michael H. Williamson

Information Systems and Engineering Management Research Publications

Differential astrometry measurements from the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) are used to constrain the astrometric orbit of the previously known ≲2 day subsystem in the triple system 63 Gem A and have detected a previously unknown two-year Keplerian wobble superimposed on the visual orbit of the much longer period (213 years) binary system HR 2896. 63 Gem A was already known to be triple from spectroscopic work, and absorption lines from all three stars can be identified and their individual Doppler shifts measured; new velocities for all three components are presented to aid in constraining the …

The Phases Differential Astrometry Data Archive. Iii. Limits To Tertiary Companions, Matthew W. Muterspaugh, Benjamin F. Lane, Shrinivas R. Kulkarni, Maciej Konacki, Bernard F. Burke, Mark M. Colavita, Michael Shao

Information Systems and Engineering Management Research Publications

The Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) monitored 51 subarcsecond binary systems to evaluate whether tertiary companions as small as Jovian planets orbited either the primary or secondary stars, perturbing their otherwise smooth Keplerian motions. Twenty-one of those systems were observed 10 or more times and show no evidence of additional companions. A new algorithm is presented for identifying astrometric companions and establishing the (companion mass)–(orbital period) combinations that can be excluded from existence with high confidence based on the PHASES observations, and the regions of mass–period phase space being excluded are presented for 21 PHASES binaries.

The Phases Differential Astrometry Data Archive. I. Measurements And Description, Matthew W. Muterspaugh, Benjamin F. Lane, Shrinivas R. Kulkarni, Maciej Konacki, Bernard F. Burke, Mark M. Colavita, Michael Shao, Sloane J. Wiktorowicz, Julia O'Connell

Information Systems and Engineering Management Research Publications

The Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) monitored 51 subarcsecond binary systems to determine precision binary orbits, study the geometries of triple and quadruple star systems, and discover previously unknown faint astrometric companions as small as giant planets. PHASES measurements made with the Palomar Testbed Interferometer (PTI) from 2002 until PTI ceased normal operations in late 2008 are presented. Infrared differential photometry of several PHASES targets were measured with Keck Adaptive Optics and are presented.

Rotation Periods Of Exoplanet Host Stars, E. K. Simpson, Sallie L. Baliunas, Gregory W. Henry, Christopher A. Watson

Information Systems and Engineering Management Research Publications

The stellar rotation periods of 10 exoplanet host stars have been determined using newly analysed Ca ii H&K flux records from the Mount Wilson Observatory and Strömgren b, y photometric measurements from Tennessee State University's automatic photometric telescopes at the Fairborn Observatory. Five of the rotation periods have not previously been reported, with that of HD 130322 very strongly detected at Prot= 26.1 ± 3.5 d. The rotation periods of five other stars have been updated using new data. We use the rotation periods to derive the line-of-sight inclinations of the stellar rotation axes, which may be used to probe …

The Lick–Carnegie Exoplanet Survey: A 3.1 M⊕ Planet In The Habitable Zone Of The Nearby M3v Star Gliese 581, Steve Vogt, R. Paul Butler, Eugenio J. Rivera, Nader Haghighipour, Gregory W. Henry, Michael H. Williamson

Information Systems and Engineering Management Research Publications

We present 11 years of HIRES precision radial velocities (RVs) of the nearby M3V star Gliese 581, combining our data set of 122 precision RVs with an existing published 4.3-year set of 119 HARPS precision RVs. The velocity set now indicates six companions in Keplerian motion around this star. Differential photometry indicates a likely stellar rotation period of ∼94 days and reveals no significant periodic variability at any of the Keplerian periods, supporting planetary orbital motion as the cause of all the RV variations. The combined data set strongly confirms the 5.37-day, 12.9-day, 3.15-day, and 67-day planets previously announced by …

New Precision Orbits Of Bright Double-Lined Spectroscopic Binaries. V. The Am Stars Hd 434 And 41 Sextantis, Francis C. Fekel, Michael H. Williamson

Information Systems and Engineering Management Research Publications

We have detected the secondary component in two previously known spectroscopic binaries, HD 434 and 41 Sex, and for the first time determined double-lined orbits for them. Despite the relatively long period of 34.26 days and a moderate eccentricity of 0.32, combined with the components' rotationally broadened lines, measurement of the primary and secondary radial velocities of HD 434 has enabled us to obtain significantly improved orbital elements. While the 41 Sex system has a much shorter period of 6.167 days and a circular orbit, the estimated V mag difference of 3.2 between its components also makes this a challenging …

Xmm-Newton Observations Of Hd 189733 During Planetary Transits, Ignazio Pillitteri, Scott J. Wolk, Ofer Cohen, Vinay Kashyap, Heather Knutson, Carey M. Lisse, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We report on two XMM-Newton observations of the planetary host star HD 189733. The system has a close in planet and it can potentially affect the coronal structure via interactions with the magnetosphere. We have obtained X-ray spectra and light curves from EPIC and the Reflection Grating Spectrometer on board XMM-Newton which we have analyzed and interpreted. We reduced X-ray data from the primary transit and secondary eclipse that occurred on 2007 April 17 and 2009 May 18, respectively. In the 2007 April observation, only variability due to weak flares is recognized. In 2009 HD 189733 exhibited an X-ray flux …

Discovery Of Cyclic Spot Activity On The G8 Giant Hd 208472, Orkun Özdarcan, Serdar Evren, Klaus G. Strassmeier, Thomas Granzer, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We present and analyze 17 consecutive years of UBVRI time-series photometry of the spotted giant component of the RS CVn binary HD 208472. Our aim is to determine the morphology and the evolution of its starspots by using periodsearch techniques and two-spot light-curve modelling. Spots on HD208472 always occur on hemispheres facing the observer during orbital quadrature and flip their location to the opposite hemisphere every approximately six years. The times when the spots change their preferential hemisphere correspond to times when the light curve amplitudes are the smallest and when abrupt changes of the photometric periods are observed. During …

The Climate Of Hd 189733b From Fourteen Transits And Eclipses Measured By Spitzer, Eric Agol, Nicolas B. Cowan, Heather A. Knutson, Drake Deming, Jason H. Steffen, Gregory W. Henry, David Charbonneau

Information Systems and Engineering Management Research Publications

We present observations of six transits and six eclipses of the transiting planet system HD 189733 taken with the Spitzer Space Telescope's Infrared Array Camera (IRAC) at 8 μm, as well as a re-analysis of previously published data. We use several novel techniques in our data analysis, the most important of which is a new correction for the detector "ramp" variation with a double-exponential function, which performs better and is a better physical model for this detector variation. Our main scientific findings are (1) an upper limit on the variability of the dayside planet flux of 2.7% (68% confidence); (2) …

A Hot Jupiter Orbiting The 1.7 M☉ Subgiant Hd 102956*, John Asher Johnson, Brendan P. Bowler, Andrew W. Howard, Gregory W. Henry, Geoffrey W. Marcy, Howard Isaacson, John Michael Brewer, Debra A. Fischer, Timothy D. Morton, Justin R. Crepp

Information Systems and Engineering Management Research Publications

We report the detection of a giant planet in a 6.4950 day orbit around the 1.68 M☉ subgiant HD 102956. The planet has a semimajor axis a = 0.081 AU and a minimum mass MPsin i =0.96 MJup. HD 102956 is the most massive star known to harbor a hot Jupiter, and its planet is only the third known to orbit within 0.6 AU of a star more massive than 1.5 M☉. Based on our sample of 137 subgiants with M⋆>1.45 M☉, we find that 0.5%–2.3% of A-type stars harbor a close-in planet (a < 0.1 AU) with MPsin i > 1 MJup, consistent with hot-Jupiter …

The California Planet Survey. I. Four New Giant Exoplanets*, Andrew W. Howard, John Asher Johnson, Geoffrey W. Marcy, Debra A. Fischer, Jason T. Wright, David Bernat, Gregory W. Henry, Kathryn M. G. Peek, Howard Isaacson, Kevin Apps, Michael Endl, William D. Cochran, Jeff A. Valenti, Jay Anderson, Nikolai E. Piskunov

Information Systems and Engineering Management Research Publications

We present precise Doppler measurements of four stars obtained during the past decade at Keck Observatory by the California Planet Survey (CPS). These stars, namely, HD 34445, HD 126614, HD 13931, and Gl 179, all show evidence for a single planet in Keplerian motion. We also present Doppler measurements from the Hobby-Eberly Telescope (HET) for two of the stars, HD 34445 and Gl 179, that confirm the Keck detections and significantly refine the orbital parameters. These planets add to the statistical properties of giant planets orbiting near or beyond the ice line, and merit follow-up by astrometry, imaging, and space-borne …

On The Transit Potential Of The Planet Orbiting Iota Draconis, Stephen R. Kane, Sabine Reffert, Gregory W. Henry, Debra A. Fischer, Christian Schwab, Kelsey I. Clubb, Christoph Bergmann

Information Systems and Engineering Management Research Publications

Most of the known transiting exoplanets are in short-period orbits, largely due to the bias inherent in detecting planets through the transit technique. However, the eccentricity distribution of the known radial velocity planets results in many of those planets having a non-negligible transit probability. One such case is the massive planet orbiting the giant star iota Draconis, a situation where both the orientation of the planet's eccentric orbit and the size of the host star inflate the transit probability to a much higher value than for a typical hot Jupiter. Here we present a revised fit of the radial velocity …

Retired A Stars And Their Companions. Iv. Seven Jovian Exoplanets From Keck Observatory, John Asher Johnson, Andrew W. Howard, Brendan P. Bowler, Gregory W. Henry, Geoffrey W. Marcy, Jason T. Wright, Debra A. Fischer, Howard Isaacson

Information Systems and Engineering Management Research Publications

We report precise Doppler measurements of seven subgiants from Keck Observatory. All seven stars show variability in their radial velocities consistent with planet-mass companions in Keplerian orbits. The host stars have masses ranging from 1.1 ≤ M⋆/M⊙ ≤ 1.9, radii 3.4 ≤ R⋆/R⊙ ≤ 6.1, and metallicities -0.21 ≤ [Fe/H] ≤ +0.26. The planets are all more massive than Jupiter (MP sin i > 1 MJup) and have semimajor axes a > 1 AU. We present millimagnitude photometry from the T3 0.4 m APT at Fairborn Observatory for five of the targets. Our monitoring shows these stars to be photometrically stable, further …

The Lick-Carnegie Exoplanet Survey: A Saturn-Mass Planet In The Habitable Zone Of The Nearby M4v Star Hip 57050, Nader Haghighipour, Steve Vogt, R. Paul Butler, Eugenio J. Rivera, Gregory Laughlin, Stefano Meschiari, Gregory W. Henry

Information Systems and Engineering Management Research Publications

Precision radial velocities (RV) from Keck/HIRES reveal a Saturn-mass planet orbiting the nearby M4V star HIP 57050. The planet has a minimum mass of Msin i ∼ 0.3 MJ, an orbital period of 41.4 days, and an orbital eccentricity of 0.31. V-band photometry reveals a clear stellar rotation signature of the host star with a period of 98 days, well separated from the period of the RV variations and reinforcing a Keplerian origin for the observed velocity variations. The orbital period of this planet corresponds to an orbit in the habitable zone of HIP 57050, with an expected planetary temperature …

New Precision Orbits Of Bright Double-Lined Spectroscopic Binaries. Iv. 66 Andromedae, Hr 6979, And Hr 9059, Francis C. Fekel, Jocelyn Tomkin, Michael H. Williamson

Information Systems and Engineering Management Research Publications

We have determined improved spectroscopic orbits for three double-lined binaries, 66 And (F4 V), HR 6979 (Am), and HR 9059 (F5 IV) using radial velocities from the 2.1 m telescope at McDonald Observatory, the coudé feed telescope at Kitt Peak National Observatory, and 2 m telescope at Fairborn Observatory. The orbital periods range from 11.0 to 14.3 days, and all three systems have eccentric orbits. The new orbital dimensions (a1 sin i and a2 sin i) and minimum masses (m1 sin3 i and m2 sin3 i) have accuracies of 0.2% or better. All six components of the three binary systems …

Hr 7355 - Another Rapidly Braking He-Strong Cp Star?, Zdeněk Mikulášek, Jiří Krtička, Gregory W. Henry, S. N. De Villiers, Ernst Paunzen, Miloslav Zejda

Information Systems and Engineering Management Research Publications

Context. Strong meridional mixing induced by rapid rotation is one reason why all hot main-sequence stars are not chemically peculiar. However, the finding that the He-strong CP star HR 7355 is a rapid rotator complicates this concept.
Aims. Our goal is to explain the observed behaviour of HR 7355 based on period analysis of all available photometry.
Methods. Over two years, we acquired 114 new BV observations of HR 7355 at observatories in Arizona, U.S.A and Cape Town, South Africa. We performed period analyses of the new observations along with new analyses of 732 archival measurements from the Hipparcos and …

Infrared Spectroscopy Of Symbiotic Stars. Viii. Orbits For Three S-Type Systems: Ae Arae, Y Coronae Australis, And Ss 73-147, Francis C. Fekel, Kenneth H. Hinkle, Richard R. Joyce, Peter R. Wood

Information Systems and Engineering Management Research Publications

With new infrared radial velocities we have computed orbits of the M giants in three southern S-type symbiotic systems. AE Ara and SS 73-147 have circular orbits with periods of 803 and 820 days, respectively. The eccentric orbit of Y CrA has a period that is about twice as long, 1619 days. Except for CH Cyg it is currently the S-type symbiotic system with the longest period for which a spectroscopic orbit has been determined. The Paschen δ emission line velocities of AE Ara are nearly in antiphase with the M giant absorption feature velocities and result in a mass …

The California Planet Survey. Ii. A Saturn-Mass Planet Orbiting The M Dwarf Gl 6491, John Asher Johnson, Andrew W. Howard, Geoffrey W. Marcy, Brendan P. Bowler, Gregory W. Henry, Debra A. Fischer, Kevin Apps, Howard Isaacson, Jason T. Wright

Information Systems and Engineering Management Research Publications

We report precise Doppler measurements of the nearby (d = 10.34 pc) M dwarf Gl 649 that reveal the presence of a planet with a minimum mass M_P sin i = 0.328 M_Jup in an eccentric (e = 0.30), 598.3 day orbit. Our photometric monitoring reveals Gl 649 to be a new variable star with brightness changes on both rotational and decadal timescales. However, neither of these timescales are consistent with the 600 day Doppler signal and so provide strong support for planetary reflex motion as the best interpretation of the observed radial velocity variations. Gl …

Refined Stellar, Orbital And Planetary Parameters Of The Eccentric Hat-P-2 Planetary System, András Pál, Gáspár Á. Bakos, Guillermo Torres, Robert W. Noyes, Debra A. Fischer, John A. Johnson, Gregory W. Henry, R. Paul Butler, Geoffrey W. Marcy, Andrew W. Howard, Brigitta Sipőcz, David W. Latham, Gilbert A. Esquerdo

Information Systems and Engineering Management Research Publications

We present refined parameters for the extrasolar planetary system HAT-P-2 (also known as HD 147506), based on new radial velocity and photometric data. HAT-P-2b is a transiting extrasolar planet that exhibits an eccentric orbit. We present a detailed analysis of the planetary and stellar parameters, yielding consistent results for the mass and radius of the star, better constraints on the orbital eccentricity and refined planetary parameters. The improved parameters for the host star are M★= 1.36 ± 0.04 M⊙ and R★= 1.64 ± 0.08 R⊙, while the planet has a mass of Mp= 9.09 ± 0.24 MJup and radius of …

A Long-Period Planet Orbiting A Nearby Sun-Like Star, Hugh R. A. Jones, R. Paul Butler, Chris Tinney, Simon O'Toole, Rob Wittenmyer, Gregory W. Henry, Stefano Meschiari, Steve Vogt, Eugenio Rivera, Greg Laughlin, Brad D. Carter, Jeremy Bailey, James S. Jenkins

Information Systems and Engineering Management Research Publications

The Doppler wobble induced by the extra-solar planet HD 134987b was first detected by data from the Keck Telescope nearly a decade ago, and was subsequently confirmed by data from the Anglo-Australian Telescope (AAT). However, as more data have been acquired for this star over the years since, the quality of a single Keplerian fit to that data has been getting steadily worse. The best-fitting single Keplerian to the 138 Keck and AAT observations now in hand has an root-mean-square (rms) scatter of 6.6 m s−1. This is significantly in excess of both the instrumental precision achieved by both the …