doi:10.1088/0004-6256/135/1/68 THE ROTATION PERIOD OF THE PLANET-HOSTING STAR HD 189733 (2009)
Gregory W. Henry, Joshua N. Winn
We present synoptic optical photometry of HD 189733, the chromospherically active parent star of one of the most intensively studied exoplanets. We have significantly extended the timespan of our...
Hirano, Teruyuki, Suto, Yasushi, Taruya, Atsushi, Narita, Norio, Sato, Bun'ei, Johnson, John Asher, ...
We obtain analytical expressions for the velocity anomaly due to the Rossiter-McLaughlin effect, for the case when the anomalous radial velocity is obtained by cross-correlation with a stellar...
Misaligned spin and orbital axes cause the anomalous precession of DI Herculis (2009)
Albrecht, Simon, Reffert, Sabine, Snellen, Ignas A. G., Winn, Joshua N.
The orbits of binary stars precess as a result of general relativistic effects, forces arising from the asphericity of the stars, and forces from additional stars or planets in the system. For most...
Carter, Joshua A., Winn, Joshua N.
We consider the problem of fitting a parametric model to time-series data that are afflicted by correlated noise. The noise is represented by a sum of two stationary Gaussian processes: one that is...
HAT-P-7: A Retrograde or Polar Orbit, and a Third Body (2009)
Winn, Joshua N., Johnson, John Asher, Albrecht, Simon, Howard, Andrew W., Marcy, Geoffrey W., Crossfield, Ian J., ...
We show that the exoplanet HAT-P-7b has an extremely tilted orbit, with a true angle of at least 86 degrees with respect to its parent star's equatorial plane, and a strong possibility of retrograde...
A Third Exoplanetary System with Misaligned Orbital and Stellar Spin Axes (2009)
Johnson, John A., Winn, Joshua N., Albrecht, Simon, Howard, Andrew W., Marcy, Geoffrey W., Gazak, J. Zachary
We present evidence that the WASP-14 exoplanetary system has misaligned orbital and stellar-rotational axes, with an angle lambda = 33.1 +/- 7.4 deg between their sky projections. The evidence is...
The Transit Ingress and the Tilted Orbit of the Extraordinarily Eccentric Exoplanet HD 80606b (2009)
Winn, Joshua N., Howard, Andrew W., Johnson, John Asher, Marcy, Geoffrey W., Gazak, J. Zachary, Starkey, Donn, ...
We present the results of a transcontinental campaign to observe the 2009 June 5 transit of the exoplanet HD 80606b. We report the first detection of the transit ingress, revealing the transit...
Improved Measurement of the Rossiter-McLaughlin Effect in the Exoplanetary System HD 17156 (2009)
Narita, Norio, Hirano, Teruyuki, Sato, Bun'ei, Winn, Joshua N., Suto, Yasushi, Turner, Edwin L., ...
We present an improved measurement of the Rossiter-McLaughlin effect for the exoplanetary system HD 17156, based on radial-velocity data gathered with the Subaru 8.2m telescope throughout the...
The Transit Light Curve Project. XII. Six Transits of the Exoplanet XO-2b (2009)
Fernandez, Jose M., Holman, Matthew J., Winn, Joshua N., Torres, Guillermo, Shporer, Avi, Mazeh, Tsevi, ...
We present photometry of six transits of the exoplanet XO-2b. By combining the light-curve analysis with theoretical isochrones to determine the stellar properties, we find the planetary radius to be...
The Spin-Orbit Misalignment of the XO-3 Exoplanetary System (2009)
Winn, Joshua N., Johnson, John Asher, Fabrycky, Daniel, Howard, Andrew W., Marcy, Geoffrey W., Narita, Norio, ...
We present photometric and spectroscopic observations of the 2009 Feb. 2 transit of the exoplanet XO-3b. The new data show conclusively that the planetary orbital axis and stellar rotation axis are...
Near-infrared transit photometry of the exoplanet HD 149026b (2009)
Carter, Joshua A., Winn, Joshua N., Gilliland, Ronald, Holman, Matthew J.
The transiting exoplanet HD 149026b is an important case for theories of planet formation and planetary structure, because the planet's relatively small size has been interpreted as evidence for a...
Fabrycky, Daniel C., Winn, Joshua N.
One possible diagnostic of planet formation, orbital migration, and tidal evolution is the angle psi between a planet's orbital axis and the spin axis of its parent star. In general, psi cannot be...
Sozzetti, Alessandro, Torres, Guillermo, Charbonneau, David, Winn, Joshua N., Korzennik, Sylvain G., Holman, Matthew J., ...
We report new spectroscopic and photometric observations of the parent stars of the recently discovered transiting planets TrES-3 and TrES-4. A detailed abundance analysis based on high-resolution...
Sozzetti, Alessandro, Torres, Guillermo, Charbonneau, David, Winn, Joshua N., Korzennik, Sylvain G., Holman, Matthew J., ...
We report new spectroscopic and photometric observations of the parent stars of the recently discovered transiting planets TrES-3 and TrES-4. A detailed abundance analysis based on high-resolution...
Winn, Joshua N., Holman, Matthew J., Carter, Joshua A., Torres, Guillermo, Osip, David J., Beatty, Thomas
We present photometry of two transits of the giant planet WASP-4b with a photometric precision of 400-800 parts per million and a time sampling of 25-40 seconds. The two midtransit times are...
A Smaller Radius for the Transiting Exoplanet WASP-10b (2008)
Johnson, John A., Winn, Joshua N., Cabrera, Nicole E., Carter, Joshua A.
We present photometry of WASP-10 during the transit of its short-period Jovian planet. We employed the novel PSF-shaping capabilities the OPTIC camera mounted on the UH 2.2m telescope to achieve a...
Madhusudhan, N., Winn, Joshua N.
We present a search for Trojan companions to 25 transiting exoplanets. We use the technique of Ford & Gaudi, in which a difference is sought between the observed transit time and the transit time...
The Transit Light Curve Project. X. A Christmas Transit of HD 17156b (2008)
Winn, Joshua N., Holman, Matthew J., Henry, Gregory W., Torres, Guillermo, Fischer, Debra, Johnson, John Asher, ...
Photometry is presented of the Dec. 25, 2007 transit of HD 17156b, which has the longest orbital period and highest orbital eccentricity of all the known transiting exoplanets. New measurements of...
Lunine, Jonathan I., Fischer, Debra, Hammel, H. B., Henning, Thomas, Hillenbrand, Lynne, Kasting, James, ...
[No abstract]
Analytic approximations for transit light curve observables and uncertainties (2008)
Carter, Joshua A., Yee, Jennifer C., Eastman, Jason, Gaudi, B. Scott, Winn, Joshua N.
The light curve of an exoplanetary transit can be used to estimate the planetary radius and other parameters of interest. Because accurate parameter estimation is a non-analytic and computationally...
The prograde orbit of exoplanet TrES-2b (2008)
Winn, Joshua N., Johnson, John Asher, Narita, Norio, Suto, Yasushi, Turner, Edwin L., Fischer, Debra A., ...
We monitored the Doppler shift of the G0 V star TrES-2 throughout a transit of its giant planet. The anomalous Doppler shift due to stellar rotation (the Rossiter-McLaughlin effect) is discernible in...
Measuring accurate transit parameters (2008)
By observing the transits of exoplanets, one may determine many fundamental system parameters. I review current techniques and results for the parameters that can be measured with the greatest...
A Search for Exotrojans in Transiting Exoplanetary systems (2008)
Madhusudhan, N., Winn, Joshua N.
We present a search for Trojan companions to 25 transiting exoplanets. We use the technique of Ford & Gaudi 2006, in which a difference is sought between the observed transit time and the transit...
A Precise Estimate of the Radius of HD 149026b (2008)
Nutzman, Philip, Charbonneau, David, Winn, Joshua N., Knutson, Heather A., Fortney, Jonathan J., Holman, Matthew J., ...
We present Spitzer 8 micron transit observations of the extrasolar planet system HD 149026. At this wavelength, transit light curves are weakly affected by stellar limb-darkening, allowing for a...
Toward a homogeneous set of transiting planet parameters (2008)
Torres, Guillermo, Winn, Joshua N., Holman, Matthew J.
With 40 or more transiting exoplanets now known, the time is ripe to seek patterns and correlations among their observed properties, which may give important insights into planet formation,...
Measurement of the Spin-Orbit Angle of Exoplanet HAT-P-1b (2008)
Johnson, John A., Winn, Joshua N., Narita, Norio, Enya, Keigo, Williams, Peter K. G., Marcy, Geoffrey W., ...
We present new spectroscopic and photometric observations of the HAT-P-1 planetary system. Spectra obtained during three transits exhibit the Rossiter-McLaughlin effect, allowing us to measure the...
Photometric Follow-up Observations of the Transiting Neptune-Mass Planet GJ 436b (2008)
Shporer, Avi, Mazeh, Tsevi, Pont, Frederic, Winn, Joshua N., Holman, Matthew J., Latham, David W., ...
This paper presents multi-band photometric follow-up observations of the Neptune-mass transiting planet GJ 436b, consisting of 5 new ground-based transit light curves obtained in May 2007. Together...
A Precise Estimate of the Radius of the Exoplanet HD 149026b from Spitzer Photometry (2008)
Nutzman, Philip, Charbonneau, David, Winn, Joshua N., Knutson, Heather A., Fortney, Jonathan J., Holman, Matthew J., ...
We present Spitzer 8 micron transit observations of the extrasolar planet HD 149026b. At this wavelength, transit light curves are weakly affected by stellar limb-darkening, allowing for a simpler...
Analytic Approximations for Transit Light Curve Observables, Uncertainties, and Covariances (2008)
Carter, Joshua A., Yee, Jennifer C., Eastman, Jason, Gaudi, B. Scott, Winn, Joshua N.
The light curve of an exoplanetary transit can be used to estimate the planetary radius and other parameters of interest. Because accurate parameter estimation is a non-analytic and computationally...
The Transit Light Curve Project. IX. Evidence for a Smaller Radius of the Exoplanet XO-3b (2008)
Winn, Joshua N., Holman, Matthew J., Torres, Guillermo, McCullough, Peter, Johns-Krull, Christopher M., Latham, David W., ...
We present photometry of 13 transits of XO-3b, a massive transiting planet on an eccentric orbit. Previous data led to two inconsistent estimates of the planetary radius. Our data strongly favor the...
The Transit Light Curve Project. VIII. Six Occultations of the Exoplanet TrES-3 (2008)
Winn, Joshua N., Holman, Matthew J., Shporer, Avi, Fernandez, Jose, Mazeh, Tsevi, Latham, David W., ...
We present photometry of the exoplanet host star TrES-3 spanning six occultations (secondary eclipses) of its giant planet. No flux decrements were detected, leading to 99%-confidence upper limits on...
The Prograde Orbit of Exoplanet TrES-2b (2008)
Winn, Joshua N., Johnson, John Asher, Narita, Norio, Suto, Yasushi, Turner, Edwin L., Fischer, Debra A., ...
We monitored the Doppler shift of the G0V star TrES-2 throughout a transit of its giant planet. The anomalous Doppler shift due to stellar rotation (the Rossiter-McLaughlin effect) is discernible in...
Reflected Light from Sand Grains in the Terrestrial Zone of a Protoplanetary Disk (2008)
Herbst, William, Hamilton, Catrina M., LeDuc, Katherine, Winn, Joshua N., Johns-Krull, Christopher M., Mundt, Reinhard, ...
We show that grains have grown to ~mm size (sand sized) or larger in the terrestrial zone (within ~3 AU) of the protoplanetary disk surrounding the 3 Myr old binary star KH 15D. We also argue that...
The Central Component of Gravitational Lens Q0957+561 (2008)
Haarsma, Deborah B., Winn, Joshua N., Shapiro, Irwin, Lehár, Joseph
In 1981, a faint radio source (G') was detected near the center of the lensing galaxy of the famous "twin quasar" Q0957+561. It is still unknown whether this central radio source is a third quasar...
Reflected light from sand grains in the terrestrial zone of a protoplanetary disk (2008)
Herbst, William, Hamilton, Catrina M., Leduc, Katherine, Winn, Joshua N., Johns-Krull, Christopher M., Mundt, Reinhard, ...
In the standard model of terrestrial planet formation, the first step in the process is for interstellar dust to coagulate within a protoplanetary disk surrounding a young star, forming large grains...
Lunine, Jonathan I., Fischer, Debra, Hammel, H. B., Henning, Thomas, Hillenbrand, Lynne, Kasting, James, ...
Not Available
A Possible Spin-Orbit Misalignment in the Transiting Eccentric Planet HD 17156b (2007)
Narita, Norio, Sato, Bun'ei, Ohshima, Osamu, Winn, Joshua N.
We present simultaneous photometric and spectroscopic observations of HD 17156b spanning a transit on UT 2007 November 12. This system is of special interest because of its 21-day period (unusually...
Liu, Xin, Turner, Edwin L., Narita, Norio, Suto, Yasushi, Winn, Joshua N., Yamada, Toru, ...
We present a new technique for detecting scattered starlight from transiting, close-orbiting extrasolar giant planets (CEGPs) that has the virtues of simplicity, robustness, linearity, and...
Five New Transits of the Super-Neptune HD 149026 (2007)
Winn, Joshua N., Henry, Gregory W., Torres, Guillermo, Holman, Matthew J.
We present new photometry of HD 149026 spanning five transits of its "super-Neptune" planet. In combination with previous data, we improve upon the determination of the planet-to-star radius ratio:...
Precise Photometry and Spectroscopy of Transits (2007)
A planetary transit produces both a photometric signal and a spectroscopic signal. Precise observations of the transit light curve reveal the planetary radius and allow a search for timing anomalies...
The Transit Light Curve Project. VII. The Not-So-Bloated Exoplanet HAT-P-1b (2007)
Winn, Joshua N, Holman, Matthew J, Bakos, Gaspar Á, Pál, András, Johnson, John Asher, Williams, Peter K G, ...
We present photometry of the G0 star HAT-P-1 during six transits of its close-in giant planet, and we refine the estimates of the system parameters. Relative to Jupiter's properties, HAT-P-1b is 1.20...
The Rotation Period of the Planet-Hosting Star HD 189733 (2007)
Henry, Gregory W., Winn, Joshua N.
We present synoptic optical photometry of HD 189733, the chromospherically active parent star of one of the most intensively studied exoplanets. We have significantly extended the timespan of our...
The Transit Light Curve (TLC) Project. VI. Three Transits of the Exoplanet TrES-2 (2007)
Holman, Matthew J., Winn, Joshua N., Latham, David W., O'Donovan, Francis T., Charbonneau, David, Torres, Guillermo, ...
Of the nearby transiting exoplanets that are amenable to detailed study, TrES-2 is both the most massive and the one with the largest impact parameter. We present z-band photometry of three transits...
The Transit Light Curve Project. VII. The Not-So-Bloated Exoplanet HAT-P-1b (2007)
Winn, Joshua N., Holman, Matthew J., Bakos, Gaspar A., Pal, Andras, Johnson, John Asher, Williams, Peter K. G., ...
We present photometry of the G0 star HAT-P-1 during six transits of its close-in giant planet, and we refine the estimates of the system parameters. Relative to Jupiter's properties, HAT-P-1b is 1.20...
Spin-Orbit Alignment for the Eccentric Exoplanet HD 147506b (2007)
Winn, Joshua N., Johnson, John Asher, Peek, Kathryn M. G., Marcy, Geoffrey W., Bakos, Gaspar A., Enya, Keigo, ...
The short-period exoplanet HD 147506b (also known as HAT-P-2b) has an eccentric orbit, raising the possibility that it migrated through planet-planet scattering or Kozai oscillations accompanied by...
The Transit Light Curve Project. VI. Three Transits of the Exoplanet TrES-2 (2007)
Holman, Matthew J., Winn, Joshua N., Latham, David W., O'Donovan, Francis T., Charbonneau, David, Torres, Guillermo, ...
Of the nearby transiting exoplanets that are amenable to detailed study, TrES-2 is both the most massive and has the largest impact parameter. We present z-band photometry of three transits of...
Measurement of the Rossiter--McLaughlin Effect in the Transiting Exoplanetary System TrES-1 (2007)
Narita, Norio, Enya, Keigo, Sato, Bun'ei, Ohta, Yasuhiro, Winn, Joshua N., Suto, Yasushi, ...
We report a measurement of the Rossiter--McLaughlin effect in the transiting extrasolar planetary system TrES-1, via simultaneous spectroscopic and photometric observations with the Subaru and MAGNUM...
CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources (2007)
Healey, Stephen E., Romani, Roger W., Taylor, Gregory B., Sadler, Elaine M., Ricci, Roberto, Murphy, Tara, ...
We have assembled an 8.4 GHz survey of bright, flat-spectrum (alpha > -0.5) radio sources with nearly uniform extragalactic (|b|>10 deg) coverage for sources brighter than S_{4.8 GHz} = 65 mJy. The...
A FIVE NEW TRANSITS OF THE SUPER-NEPTUNE HD 149026b (2007)
Joshua N. Winn, Gregory W. Henry, Guillermo Torres, Matthew J. Holman
We present new photometry of HD 149026 spanning five transits of its ‘‘super-Neptune’ ’ planet. In combination with previous data, we improve on the determination of the planet-to-star radius...
Exoplanets and the Rossiter-McLaughlin Effect (2006)
A transiting planet eclipses part of the rotating stellar surface, thereby producing an anomalous Doppler shift of the stellar spectrum. Here I review how this "Rossiter-McLaughlin Effect" can be...
Winn, Joshua N., Holman, Matthew J., Henry, Gregory W., Roussanova, Anna, Enya, Keigo, Yoshii, Yuzuru, ...
We present photometry of HD 189733 during eight transits of its close-in giant planet, and out-of-transit photometry spanning two years. Using the transit photometry, we determine the stellar and...
The Transit Light Curve Project. I. Four Consecutive Transits of the Exoplanet XO-1b (2006)
Holman, Matthew J., Winn, Joshua N., Latham, David W., O'Donovan, Francis T., Charbonneau, David, Bakos, Gáspár A., ...
We present RIz photometry of four consecutive transits of the newly discovered exoplanet XO-1b. We improve on the estimates of the transit parameters, finding the planetary radius to be RP = 1.184...
The Transit Light Curve Project. III. Tres Transits of TrES-1 (2006)
Winn, Joshua N., Holman, Matthew J., Roussanova, Anna
We present z band photometry of three consecutive transits of the exoplanet TrES-1, with an accuracy of 0.15% and a cadence of 40 seconds. We improve upon estimates of the system parameters, finding...
Measurement of the Spin-Orbit Alignment in the Exoplanetary System HD 189733 (2006)
Winn, Joshua N., Johnson, John A., Marcy, Geoffrey W., Butler, R. Paul, Vogt, Steven S., Henry, Gregory W., ...
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),...
The Transit Light Curve (TLC) Project. II. Two Transits of the Exoplanet OGLE-TR-111b (2006)
Winn, Joshua N., Holman, Matthew J., Fuentes, Cesar I.
As part of our ongoing effort to measure exoplanet sizes and transit times with greater accuracy, we present I band observations of two transits of OGLE-TR-111b. The photometry has an accuracy of...
TrES-2: The First Transiting Planet in the Kepler Field (2006)
O'Donovan, Francis T., Charbonneau, David, Mandushev, Georgi, Dunham, Edward W., Latham, David W., Torres, Guillermo, ...
We announce the discovery of the second transiting hot Jupiter discovered by the Trans-atlantic Exoplanet Survey. The planet, which we dub TrES-2, orbits the nearby star GSC 03549-02811 every 2.47063...
Gaudi, B. Scott, Winn, Joshua N.
The Rossiter-McLaughlin (RM) effect is the distortion of stellar spectral lines that occurs during eclipses or transits, due to stellar rotation. We assess the future prospects for using the RM...
The Transit Light Curve (TLC) Project. I. Four Consecutive Transits of the Exoplanet XO-1b (2006)
Holman, Matthew J., Winn, Joshua N., Latham, David W., O'Donovan, Francis T., Charbonneau, David, Bakos, Gaspar A., ...
We present RIz photometry of four consecutive transits of the newly discovered exoplanet XO-1b. We improve upon the estimates of the transit parameters, finding the planetary radius to be R_P = 1.184...
Boyce, Edward R., Winn, Joshua N., Hewitt, Jacqueline N., Myers, Steven T.
The Extragalactic Lens VLBI Imaging Survey (ELVIS) searches for central images of lensed radio quasars, in order to measure the central density profiles of distant galaxies. Here we present sensitive...
The Orbit and Occultations of KH 15D (2006)
Winn, Joshua N., Hamilton, Catrina M., Herbst, William J., Hoffman, Jennifer L., Holman, Matthew J., Johnson, John A., ...
The unusual flux variations of the pre-main-sequence binary star KH 15D have been attributed to occultations by a circumbinary disk. We test whether or not this theory is compatible with newly...
Joshua N. Winn, Matthew J. Holman, Gregory W. Henry, Anna Roussanova, Keigo Enya, Yuzuru Yoshii, ...
We present photometry of HD 189733 during eight transits of its close-in giant planet, and out-of-transit photometry spanning 2 yr. Using the transit photometry, we determine the stellar and...
Joshua N. Winn, John Asher Johnson, Geoffrey W. Marcy, R. Paul Butler, Steven S. Vogt, Gregory W. Henry, ...
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),...
Transit Photometry of the Core-Dominated Planet HD 149026b (2005)
Charbonneau, David, Winn, Joshua N., Latham, David W., Bakos, Gaspar, Falco, Emilio E., Holman, Matthew J., ...
We report g, V, and r photometric time series of HD 149026 spanning predicted times of transit of the Saturn-mass planetary companion, which was recently discovered by Sato and collaborators. We...
The Transit Light Curve Project. IV. Five Transits of the Exoplanet OGLE-TR-10b (2005)
Holman, Matthew J., Winn, Joshua N., Fuentes, Cesar I., Hartman, Joel D., Stanek, K. Z., Torres, Guillermo, ...
We present I and B photometry of five distinct transits of the exoplanet OGLE-TR-10b. By modeling the light curves, we find the planetary radius to be R_P = 1.06 +/- 0.08 R_Jup and the stellar radius...
Obliquity Tides on Hot Jupiters (2005)
Winn, Joshua N., Holman, Matthew J.
Obliquity tides are a potentially important source of heat for extrasolar planets on close-in orbits. Although tidal dissipation will usually reduce the obliquity to zero, a nonzero obliquity can...
Subaru HDS Transmission Spectroscopy of the Transiting Extrasolar Planet HD 209458b (2005)
Narita, Norio, Suto, Yasushi, Winn, Joshua N., Turner, Edwin L., Aoki, Wako, Leigh, Christopher J., ...
We have searched for absorption in several common atomic species due to the atmosphere or exosphere of the transiting extrasolar planet HD 209458b, using high precision optical spectra obtained with...
Measurement of Spin-Orbit Alignment in an Extrasolar Planetary System (2005)
Winn, Joshua N., Noyes, Robert W., Holman, Matthew J., Charbonneau, David, Ohta, Yasuhiro, Taruya, Atsushi, ...
We determine the stellar, planetary, and orbital properties of the transiting planetary system HD 209458, through a joint analysis of high-precision radial velocities, photometry, and timing of the...
Johnson, John Asher, Winn, Joshua N., Rampazzi, Francesca, Barbieri, Cesare, Mito, Hiroyuki, Tarusawa, Ken-ichi, ...
The unusual pre-main-sequence binary star named KH 15D undergoes remarkably deep and long-lasting periodic eclipses. Some clues about the reason for these eclipses have come from the observed...
The Radio Variability of the Gravitational Lens PMN J1838-3427 (2004)
Winn, Joshua N., Lovell, James E. J., Bignall, Hayley, Gaensler, Bryan M., Getts, Tracy J., Kedziora-Chudczer, Lucyna, ...
We present the results of a radio variability study of the gravitational lens PMN J1838-3427. Our motivation was to determine the Hubble constant by measuring the time delay between variations of the...
Winn, Joshua N., Suto, Yasushi, Turner, Edwin L., Narita, Norio, Frye, Brenda L., Aoki, Wako, ...
There is evidence that the transiting planet HD 209458b has a large exosphere of neutral hydrogen, based on a 15% decrement in Lyman-alpha flux that was observed by Vidal-Madjar et al. during...
The radio variability of the gravitational lens PMN J1838-3427 (2004)
Winn, Joshua N., Lovell, James E., Bignall, Hayley E., Gaensler, Bryan M., Getts, Tracy J., Kedziora-Chudczer, Lucyna L., ...
We present the results of a radio variability study of the gravitational lens PMN J1838-3427. Our motivation was to determine the Hubble constant by measuring the time delay between variations of the...
The radio variability of the gravitational lens PMN J1838-3427 (2004)
Winn, Joshua N., Lovell, James E., Bignall, Hayley E., Gaensler, Bryan M., Getts, Tracy J., Kedziora-Chudczer, Lucyna L., ...
We present the results of a radio variability study of the gravitational lens PMN J1838-3427. Our motivation was to determine the Hubble constant by measuring the time delay between variations of the...
The radio variability of the gravitational lens PMN J1838-3427 (2004)
Winn, Joshua N., Lovell, James E., Bignall, Hayley E., Gaensler, Bryan M., Getts, Tracy J., Kedziora-Chudczer, Lucyna L., ...
We present the results of a radio variability study of the gravitational lens PMN J1838-3427. Our motivation was to determine the Hubble constant by measuring the time delay between variations of the...
The radio variability of the gravitational lens PMN J1838-3427 (2004)
Winn, Joshua N., Lovell, James E., Bignall, Hayley E., Gaensler, Bryan M., Getts, Tracy J., Kedziora-Chudczer, Lucyna L., ...
We present the results of a radio variability study of the gravitational lens PMN J1838-3427. Our motivation was to determine the Hubble constant by measuring the time delay between variations of the...
The radio variability of the gravitational lens PMN J1838-3427 (2004)
Winn, Joshua N., Lovell, James E., Bignall, Hayley E., Gaensler, Bryan M., Getts, Tracy J., Kedziora-Chudczer, Lucyna L., ...
We present the results of a radio variability study of the gravitational lens PMN J1838-3427. Our motivation was to determine the Hubble constant by measuring the time delay between variations of the...
KH 15D: Gradual Occultation of a Pre-Main-Sequence Binary (2003)
Winn, Joshua N., Holman, Matthew J., Johnson, John A., Stanek, Krzysztof Z., Garnavich, Peter M.
We propose that the extraordinary ``winking star'' KH 15D is an eccentric pre-main-sequence binary that is gradually being occulted by an opaque screen. This model accounts for the periodicity,...
The History of the Mysterious Eclipses of KH 15D: Asiago Observatory, 1967-1982 (2003)
Johnson, John A., Winn, Joshua N.
We are gathering archival observations to determine the photometric history of the unique and unexplained eclipses of the pre-main-sequence star KH 15D. Here we present a light curve from 1967-1982,...
The central image of a gravitationally lensed quasar (2003)
Winn, Joshua N., Rusin, David, Kochanek, Christopher S.
A galaxy can act as a gravitational lens, producing multiple images of a background object. Theory predicts there should be an odd number of images but, paradoxically, almost all observed lenses have...
Mass and dust in the disk of a spiral lens galaxy (2003)
Winn, Joshua N., Hall, Patrick B., Schechter, Paul L.
Gravitational lensing is a potentially important probe of spiral galaxy structure, but only a few cases of lensing by spiral galaxies are known. We present Hubble Space Telescope and Magellan...
Limits on eclipses of the pre-main-sequence star KH 15D in the first half of the 20th century (2003)
Winn, Joshua N., Garnavich, Peter M., Stanek, K. Z., Sasselov, Dimitar D.
Over the last decade, the pre-main sequence star KH 15D has exhibited periodic eclipses that are surprisingly deep (~3 mag) and long-lasting (~40% of the 48.4-day period). The cause of the eclipses...
The Quintuple Quasar: Radio and Optical Observations (2003)
Winn, Joshua N., Kochanek, Christopher S., Keeton, Charles R., Lovell, James E. J.
We present results from high-resolution radio and optical observations of PMN J0134-0931, a gravitational lens with a unique radio morphology and an extremely red optical counterpart. Our data...
The Quintuple Quasar: Mass Models and Interpretation (2003)
Keeton, Charles R., Winn, Joshua N.
The strange morphology of the six-component gravitational lens PMN J0134-0931 has resisted explanation. We present the first successful quantitative models for the system, based on the idea that...
Winn, Joshua N., Rusin, David, Kochanek, Christopher S.
We present multi-frequency VLBA observations of PMN J1632-0033, one of the few gravitationally lensed quasars suspected of having a central ``odd'' image. The central component has a different...
Interferometric Phase Calibration Sources in the Declination Range 0deg to -30deg (2002)
Winn, Joshua N., Patnaik, Alok R., Wrobel, J. M.
We present a catalog of 321 compact radio sources in the declination range 0deg > delta > -30deg. The positions of these sources have been measured with a two-dimensional rms accuracy of 35...
The Multi-Band Magnification Bias for Gravitational Lenses (2002)
Wyithe, J. Stuart B., Winn, Joshua N., Rusin, David
We present a generalization of the concept of magnification bias for gravitationally-lensed quasars, in which the quasars are selected by flux in more than one wavelength band. To illustrate the...
Analytic expressions for mean magnification by a quadrupole gravitational lens (2002)
Finch, Tehani K., Carlivati, Lisa P., Winn, Joshua N., Schechter, Paul L.
We derive an analytic expression for the mean magnification due to strong gravitational lensing, using a simple lens model, a singular isothermal sphere embedded in an external shear field. We...
PKS 1830-211: A Face-On Spiral Galaxy Lens (2002)
Winn, Joshua N., Kochanek, Christopher S., McLeod, Brian A., Falco, Emilio E., Impey, Christopher D., Rix, Hans-Walter
We present new Hubble Space Telescope images of the gravitational lens PKS 1830-211, which allow us to characterize the lens galaxy and update the determination of the Hubble constant from this...
PKS 1830-211: A Face-on Spiral Galaxy Lens (2002)
Winn, Joshua N., Kochanek, Christopher S., McLeod, Brian A., Falco, Emilio E., Impey, Christopher D., Rix, Hans-Walter
PMN J0134-0931: A gravitationally lensed quasar with an unusual radio morphology (2001)
Winn, Joshua N., Lovell, James E. J., Chen, Hsiao-Wen, Fletcher, Andre B., Hewitt, Jacqueline N., Patnaik, Alok R., ...
The radio-loud quasar PMN J0134-0931 was discovered to have an unusual morphology during our search for gravitational lenses. In VLA and MERLIN images, there are 5 compact components with maximum...
PMN J1632-0033: A new gravitationally lensed quasar (2001)
Winn, Joshua N., Morgan, Nicholas D., Hewitt, Jacqueline N., Kochanek, Christopher S., Lovell, James E. J., Patnaik, Alok R., ...
We report the discovery of a gravitationally lensed quasar resulting from our survey for lenses in the southern sky. Radio images of PMN J1632-0033 with the VLA and ATCA exhibit two compact,...
A search for gravitational lenses in the southern sky / (2001)
This thesis describes an astronomical survey for new gravitational lenses in the southern sky. The purpose was to find lenses that can be used to study dark matter, by modeling the lens potentials;...
A nearly symmetric double-image gravitational lens (2000)
Winn, Joshua N., Hewitt, Jacqueline N., Patnaik, Alok R., Schechter, Paul L., Schommer, Robert A., Lopez, Sebastian, ...
We report the discovery of a new double-image gravitational lens resulting from our search for lenses in the southern sky. Radio source PMN J2004-1349 is composed of two compact components separated...
PMN J1838-3427: A new gravitationally lensed quasar (2000)
Winn, Joshua N., Hewitt, Jacqueline N., Schechter, Paul L., Dressler, Alan, Falco, E. E., Impey, C. D., ...
We report the discovery of a new double-image quasar that was found during a search for gravitational lenses in the southern sky. Radio source PMN J1838-3427 is composed of two flat-spectrum...
A Close Separation Double Quasar Lensed by a Gas-Rich Galaxy (2000)
Gregg, Michael D., Wisotzki, Lutz, Becker, Robert, Maza, Jose, Schechter, Paul, White, Richard, ...
In the course of a Cycle 8 snapshot survey, we have discovered that the z=1.565 quasar HE 0512-3329 is a double with image separation 0.644", almost certainly due to gravitational lensing. The two...
CTQ 839: Candidate for the Smallest Projected Separation Binary Quasar (2000)
Morgan, Nicholas D., Burley, Greg, Costa, Edgardo, Maza, Jose, Persson, S. E., Ruiz, Maria Teresa, ...
We report the discovery of the new double quasar CTQ 839. This B = 18.3, radio quiet quasar pair is separated by 2.1" in BRIH filters with magnitude differences of delta m_B = 2.5, delta m_R = delta...
A multipole-Taylor expansion for the potential of gravitational lens MG J0414+0534 (2000)
Trotter, Catherine S., Winn, Joshua N., Hewitt, Jacqueline N.
We employ a multipole-Taylor expansion to investigate how tightly the gravitational potential of the quadruple-image lens MG J0414+0534 is constrained by recent VLBI observations. These observations...
A southern VLA-based gravitational lens search (1999)
Winn, Joshua N., Hewitt, Jacqueline N., Schechter, Paul L.
We present a status report on our search for multiple-image QSOs among southern radio sources. Our goal is to identify new lenses for use in studies of cosmology and galaxy structure. To date we have...
CTQ 414: A New Gravitational Lens (1999)
Morgan, Nicholas D., Dressler, Alan, Maza, Jose, Schechter, Paul L., Winn, Joshua N.
We report the discovery and ground based observations of the new gravitational lens CTQ 414. The source quasar lies at a redshift of z = 1.29 with a B magnitude of 17.6. Ground based optical imaging...