Scholz, Alexander, Geers, Vincent, Jayawardhana, Ray, Fissel, Laura, Lee, Eve, Lafreniere, David, ...
SONYC -- Substellar Objects in Nearby Young Clusters -- is a survey program to investigate the frequency and properties of substellar objects with masses down to a few times that of Jupiter in nearby...
Scholz, Alexander, Xu, Xiaoying, Jayawardhana, Ray, Wood, Kenneth, Eisloeffel, Jochen, Quinn, Ciara
The properties of accretion disks around stars and brown dwarfs in the SOri cluster (age 3 Myr) are studied based on NIR time series photometry supported by MIR spectral energy distributions. We...
Discovery of the Widest Very Low Mass Field Binary (2009)
Radigan, Jacqueline, Lafrenière, David, Jayawardhana, Ray, Doyon, René
We present the discovery of the widest (~6700 AU) very low mass field binary to date, found in a proper motion cross-match of the Sloan Digital Sky Survey and the Two Micron All Sky Survey. Our...
How Variable is Accretion in Young Stars? (2009)
Nguyen, Duy Cuong, Scholz, Alexander, Van Kerkwijk, Marten H., Jayawardhana, Ray, Brandeker, Alexis
We analyze the variability in accretion-related emission lines for 40 Classical T Tauri stars to probe the extent of accretion variations in young stellar objects. Our analysis is based on...
Disk-Braking in Young Stars: Probing Rotation in Chamaeleon I and Taurus-Auriga (2009)
Nguyen, Duy Cuong, Jayawardhana, Ray, Van Kerkwijk, Marten H., Brandeker, Alexis, Scholz, Alexander, Damjanov, Ivana
We present a comprehensive study of rotation, disk and accretion signatures for 144 T Tauri stars in the young (~2 Myr old) Chamaeleon I and Taurus-Auriga star forming regions based on multi-epoch...
Lafrenière, David, Jayawardhana, Ray, Van Kerkwijk, Marten H.
We present Gemini near-infrared adaptive optics imaging and spectroscopy of a planetary mass candidate companion to 1RXS J160929.1-210524, a roughly solar-mass member of the 5 Myr-old Upper Scorpius...
Lithium Depletion of Nearby Young Stellar Associations (2008)
Mentuch, Erin, Brandeker, Alexis, Van Kerkwijk, Marten H., Jayawardhana, Ray, Hauschildt, Peter H.
We estimate cluster ages from lithium depletion in five pre-main-sequence groups found within 100 pc of the Sun: TW Hydrae Association, Eta Chamaeleontis Cluster, Beta Pictoris Moving Group,...
Discovery of a Wide Substellar Companion to a Nearby Low-Mass Star (2008)
Radigan, Jacqueline, Lafrenière, David, Jayawardhana, Ray, Doyon, René
We report the discovery of a wide (135+/-25 AU), unusually blue L5 companion 2MASS J17114559+4028578 to the nearby M4.5 dwarf G 203-50 as a result of a targeted search for common proper motion pairs...
IRAS04325+2402C: A very low mass object with an edge-on disk (2008)
Scholz, Alexander, Jayawardhana, Ray, Wood, Kenneth, Lafreniere, David, Schreyer, Katharina, Doyon, Rene
IRAS04325+2402C is a low luminosity object located near a protostar in Taurus. We present new spatially-resolved mm observations, near-infrared spectroscopy, and Spitzer photometry that improve the...
A Multiplicity Census of Young Stars in Chamaeleon I (2008)
Lafreniere, David, Jayawardhana, Ray, Brandeker, Alexis, Ahmic, Mirza, Van Kerkwijk, Marten H.
We present the results of a multiplicity survey of 126 stars spanning ~0.1-3 solar masses in the ~2-Myr-old Chamaeleon I star-forming region, based on adaptive optics imaging with the ESO Very Large...
Highly Excited UV H 2 emission around TW Hya (2007)
Ray Jayawardhana, Thomas Greene, Gregory J. Herczeg, Jerey L. Linsky, Chris Johns-krull, Je Valenti
Abstract. We observed the classical T Tauri star TW Hya with HST/STIS using the E140M grating. Fluorescent H 2 emission, consisting of 129 Lyman B-X lines from 19 upper rovibrational levels,...
Millimeter Observations of the TW Hya System (2007)
Ray Jayawardhana, Thomas Greene, David J. Wilner
Abstract. We present millimeter wavelength aperture synthesis observations of TW Hya obtained with the Very Large Array and the BIMA array. Images at 7 mm resolve the dusty circumstellar disk...
TWO SUBSTELLAR COMPANIONS ORBITING HD 1684431 (2007)
Geoffrey W. Marcy, R. Paul Butler, Steven S. Vogt, Michael C. Liu, Gregory Laughlin, Kevin Apps, ...
Precise Doppler measurements during 4.4 yr from the Keck/HIRES spectrometer reveal two superimposed Keplerian velocity variations for HD 168443 (G6 IV). A simultaneous orbital t to both companions...
HST Observations of Dusty Disks in the TW Hya Association (2007)
Ray Jayawardhana, Thomas Greene, Glenn Schneider
The fortuitous proximity of the TW Hya association (TWA) enables spatially resolved studies of the distribution and physical characteristics of the dust/debris in the circumstellar environment of its...
Finding Brown Dwarf Companions with HST/NICMOS (2007)
Ray Jayawardhana, Thomas Greene, Patrick Lowrance, Eric E. Becklin, Glenn Schneider
and the NICMOS IDT EONS team & STIS 8176 team Abstract. We present the results of a HST/NICMOS coronagraphic survey for the direct detection of substellar companions within the young TW Hydrae...
Keck adaptive optics observations of TW Hydrae Association members (2007)
Ray Jayawardhana, Thomas Greene, Bruce Macintosh, Claire Max, Ben Zuckerman, Eric E. Becklin, ...
Adaptive optics (AO) on 8-10 m telescopes is an enormously powerful tool for studying young nearby stars. It is especially useful for searching for companions. Using AO on the 10-m W.M. Keck II...
Young Stars Near Earth: Progress and Prospects (2007)
Asp Conference Series, Ray Jayawardhana, Thomas Greene, S. Sciortino, F. Damiani, F. Favata, ...
We present results of our ongoing study of the low-mass members of Upper Sco-Cen based on deep BVRI photometry and XMMNewton EPIC observations purposely obtained as part of the GTO program. Analyzing...
Dusty disks at the bottom of the IMF (2007)
Scholz, Aleks, Jayawardhana, Ray
'Isolated planetary mass objects' (IPMOs) have masses close to or below the Deuterium-burning mass limit (~15 Jupiter masses) -- at the bottom of the stellar initial mass function. We present an...
Multiplicity Among Young Brown Dwarfs and Very Low Mass Stars (2007)
Ahmic, Mirza, Jayawardhana, Ray, Brandeker, Alexis, Scholz, Alexander, Van Kerkwijk, Marten H., Delgado-Donate, Eduardo, ...
Characterizing multiplicity in the very low mass (VLM) domain is a topic of much current interest and fundamental importance. Here we report on a near-IR AO imaging survey of 31 young brown dwarfs...
Damjanov, Ivana, Jayawardhana, Ray, Scholz, Alexander, Ahmic, Mirza, Nguyen, Duy C., Brandeker, Alexis, ...
We present a comprehensive study of disks around 81 young low-mass stars and brown dwarfs in the nearby ~2-Myr-old Chamaeleon I star-forming region. We use mid-infrared photometry from the Spitzer...
Stelzer, Beate, Scholz, Alexander, Jayawardhana, Ray
We have obtained a series of high-resolution optical spectra for the brown dwarf 2MASSW J1207334-393254 (2M1207) using the ESO Very Large Telescope with the UVES spectrograph during two consecutive...
The Gemini Deep Planet Survey -- GDPS (2007)
Lafreniere, David, Doyon, Rene, Marois, Christian, Nadeau, Daniel, Oppenheimer, Ben R., Roche, Patrick F., ...
We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around nearby young stars. The observations were obtained with the...
Rotation and activity of pre-main-sequence stars (2007)
Scholz, Aleks, Coffey, Jaime, Brandeker, Alexis, Jayawardhana, Ray
We present a study of rotation (vsini) and chromospheric activity (Halpha EW) based on an extensive set of high-resolution optical spectra obtained with MIKE on the 6.5m Magellan Clay telescope. Our...
Evolution of brown dwarf disks: A Spitzer survey in Upper Scorpius (2007)
Scholz, Alexander, Jayawardhana, Ray, Wood, Kenneth, Meeus, Gwendolyn, Stelzer, Beate, Walker, Christina, ...
We have carried out a Spitzer survey for brown dwarf (BD) disks in the ~5 Myr old Upper Scorpius (UpSco) star forming region, using IRS spectroscopy from 8 to 12\mu m and MIPS photometry at 24\mu m....
Deficit of wide binaries in the eta chamaeleontis young cluster (2006)
Brandeker, Alexis, Jayawardhana, Ray, Khavari, Parandis, Haisch, Karl E., Mardones, Diego
We have carried out a sensitive high-resolution imaging survey of stars in the young (6-8 Myr), nearby (97 pc) compact cluster around eta Chamaeleontis to search for stellar and substellar...
Infrared Spectroscopy of the Ultra Low Mass Binary Oph 162225-240515 (2006)
Brandeker, Alexis, Jayawardhana, Ray, Ivanov, Valentin D., Kurtev, Radostin
Binary properties are an important diagnostic of the star and brown dwarf formation processes. While wide binaries appear to be rare in the sub-stellar regime, recent observations have revealed...
Mohanty, Subhanjoy, Jayawardhana, Ray, Huelamo, Nuria, Mamajek, Eric
We present J-band imaging and H+K-band low-resolution spectroscopy of 2MASS1207-3932 AB, obtained with VLT NACO. For the putative planetary mass secondary, we find J = 20.0+/-0.2 mag. The HK spectra...
Deficit of wide binaries in the eta Chamaeleontis young cluster (2006)
Brandeker, Alexis, Jayawardhana, Ray, Khavari, Parandis, Haisch Jr, Karl E., Mardones, Diego
We have carried out a sensitive high-resolution imaging survey of stars in the young (6-8 Myr), nearby (97 pc) compact cluster around eta Chamaeleontis to search for stellar and sub-stellar...
Spectroscopy of Young Planetary Mass Candidates with Disks (2006)
Jayawardhana, Ray, Ivanov, Valentin D.
It is now well established that many young brown dwarfs exhibit characteristics similar to classical T Tauri stars, including infrared excess from disks and emission lines related to accretion....
Accretion Disks around Young Stars: Lifetimes, Disk Locking and Variability (2006)
Jayawardhana, Ray, Coffey, Jaime, Scholz, Alexander, Brandeker, Alexis, Van Kerkwijk, Marten H.
We report the findings of a comprehensive study of disk accretion and related phenomena in four of the nearest young stellar associations spanning 6-30 million years in age, an epoch that may...
Exploring brown dwarf disks: A 1.3 mm survey in Taurus (2006)
Scholz, Alexander, Jayawardhana, Ray, Wood, Kenneth
We have carried out sensitive 1.3 mm observations of 20 young brown dwarfs in the Taurus star-forming region, representing the largest sample of young substellar objects targeted in a deep millimeter...
Variable accretion and outflow in young brown dwarfs (2005)
Scholz, Alexander, Jayawardhana, Ray
We report on the first dedicated monitoring campaign of spectroscopic variability in young brown dwarfs. High-resolution optical spectra of six targets in nearby star-forming regions were obtained...
Rotation and variability of young very low mass objects (2005)
Scholz, Alexander, Jayawardhana, Ray, Eisloeffel, Jochen, Froebrich, Dirk
Variability studies are an important tool to investigate key properties of stars and brown dwarfs. From photometric monitoring we are able to obtain information about rotation and magnetic activity,...
Scholz, Alexander, Jayawardhana, Ray, Brandeker, Alexis
We report the first comprehensive study of emission line variability in an accreting young brown dwarf. We have collected 14 high-resolution optical spectra of 2MASSW J1207334-393254 (M8), a likely...
Haisch Jr., Karl E., Jayawardhana, Ray, Alves, Joao
We present new L' (3.8-micron) observations of stars in the nearby (~97 pc) young (~6 Myr) compact cluster around eta Chamaeleontis, obtained with the European Southern Observatory's Very Large...
Mohanty, Subhanjoy, Jayawardhana, Ray, Basri, Gibor
Using the largest high-resolution spectroscopic sample to date of young, very low mass stars (VLMS) and brown dwarfs (BDs), we investigate disk accretion in objects ranging from just above the...
A new Classical T Tauri object at the sub-stellar boundary in Chamaeleon II (2004)
Navascues, David Barrado Y, Jayawardhana, Ray
We have obtained low- and medium-resolution optical spectra of 20 candidate young low-mass stars and brown dwarfs in the nearby Chamaeleon II dark cloud, using the Magellan Baade telescope. We...
Navascues, David Barrado Y, Stauffer, John R., Jayawardhana, Ray
We have obtained intermediate-resolution optical spectroscopy of 44 candidate very low mass members of the nearby young open cluster IC2391. Of these, 26 spectra are totally new, 14 were already...
Flared Disks and Silicate Emission in Young Brown Dwarfs (2004)
Mohanty, Subhanjoy, Jayawardhana, Ray, Natta, Antonella, Fujiyoshi, Takuya, Tamura, Motohide, Navascues, David Barrado Y
We present mid-infrared photometry of three very young brown dwarfs located in the $\rho$ Ophiuchi star-forming region -- GY5, GY11 and GY310 --obtained with the Subaru 8-meter telescope. All three...
Measuring Fundamental Parameters of Substellar Objects. I: Surface Gravities (2004)
Mohanty, Subhanjoy, Basri, Gibor, Jayawardhana, Ray, Allard, France, Hauschildt, Peter, Ardila, David
(abridged) We present an analysis of high resolution optical spectra for a sample of very young, mid- to late M, low-mass stellar and substellar objects in Upper Sco and Taurus. Effective...
Measuring Fundamental Parameters of Substellar Objects. II: Masses and Radii (2004)
Mohanty, Subhanjoy, Jayawardhana, Ray, Basri, Gibor
We present mass and radius derivations for a sample of very young, mid- to late M, low-mass stellar and substellar objects in Upper Sco and Taurus. In a previous paper, we determined effective...
Unraveling Brown Dwarf Origins (2004)
Brown dwarfs, which occupy a fuzzy gap in mass between stars and planets, appear to be common both in the solar neighborhood and in star-forming regions. Their origin is a topic of significant...
Accretion and Outflow in the Substellar Domain: Magellan Spectroscopy of LS-RCrA 1 (2003)
Navascues, David Barrado Y, Mohanty, Subhanjoy, Jayawardhana, Ray
We present low-, medium-, and high-resolution optical spectra of LS-RCrA~1. We confirm both pre-main sequence status and membership, through the detection of lithium, presence of narrow potassium...
Close Companions to Nearby Young Stars from Adaptive Optics Imaging on VLT and Keck (2003)
Haisch Jr., Karl E., Jayawardhana, Ray, Brandeker, Alexis, Mardones, Diego
We report the results of VLT and Keck adaptive optics surveys of known members of the Eta Chamaeleontis, MBM 12, and TW Hydrae (TWA) associations to search for close companions. The multiplicity...
Between Cool Stars and Hot Planets: Origins of Brown Dwarfs (2003)
Brown dwarfs, which straddle the mass range between stars and planets, appear to be common both in the solar neighborhood and in star-forming regions. Their ubiquity makes the question of their...
Hogerheijde, Michiel R., Johnstone, Doug, Matsuyama, Isamu, Jayawardhana, Ray, Muzerolle, James
We report detection of continuum emission at 850 and 450 micron from disks around four Classical T Tauri stars in the MBM 12 (L1457) young association. Using a simple model we infer masses of...
Keck Adaptive Optics Imaging of Nearby Young Stars: Detection of Close Multiple Systems (2003)
Brandeker, Alexis, Jayawardhana, Ray, Najita, Joan
Using adaptive optics on the Keck II 10-meter telescope on Mauna Kea, we have surveyed 24 of the nearest young stars known in search of close companions. Our sample includes members of the MBM 12 and...
Magellan Echelle Spectroscopy of TW Hydrae Brown Dwarfs (2003)
Mohanty, Subhanjoy, Jayawardhana, Ray, Navascues, David Barrado Y
We present high-resolution optical spectroscopy of four candidate members of the nearby TW Hydrae young association including three brown dwarfs (2MASS 1207-3932, 2MASS 1139-3159 and TWA 5B) and one...
Observational Clues to Brown Dwarf Origins (2003)
Jayawardhana, Ray, Mohanty, Subhanjoy, Basri, Gibor, Ardila, David R., Stelzer, Beate, Haisch Jr, Karl E.
Over the past year, we have conducted a multi-faceted program to investigate the origin and early evolution of brown dwarfs. Using high-resolution Keck optical spectra of ~30 objects near and below...
A Disk Census for Young Brown Dwarfs (2003)
Jayawardhana, Ray, Ardila, David R., Stelzer, Beate, Haisch Jr, Karl E.
Recent surveys have identified sub-stellar objects down to planetary masses in nearby star-forming regions. Reliable determination of the disk frequency in young brown dwarfs is of paramount...
Evidence for a T Tauri Phase in Young Brown Dwarfs (2003)
Jayawardhana, Ray, Mohanty, Subhanjoy, Basri, Gibor
As part of a multi-faceted program to investigate the origin and early evolution of sub-stellar objects, we present high-resolution Keck optical spectra of 14 very low mass sources in the IC 348...
Probing Disk Accretion in Young Brown Dwarfs (2002)
Jayawardhana, Ray, Mohanty, Subhanjoy, Basri, Gibor
We present high-resolution optical spectra of 15 objects near or below the sub-stellar limit in the Upper Scorpius and $\rho$ Ophiuchus star-forming regions. These spectra, obtained with the HIRES...
Millimeter-wave Searches for Cold Dust and Molecular Gas around T Tauri Stars in MBM 12 (2002)
Hogerheijde, Michiel R., Jayawardhana, Ray, Johnstone, Doug, Blake, Geoffrey A., Kessler, Jacqueline E.
We report results of a sensitive search for cold dust and molecular gas in the disks around 8 T Tauri stars in the high-latitude cloud MBM 12. Interferometric observations of 3 mm continuum emission...
Jayawardhana, Ray, Ardila, David R., Stelzer, Beate
Studies of disks around young brown dwarfs are of paramount importance to our understanding of the origin, diversity and early evolution of sub-stellar objects. Here we present first results from a...
T Tauri Stars in the Small Magellanic Cloud (2002)
Ivanov, Valentin D., Jayawardhana, Ray
The Small Magellanic Cloud (SMC) is an excellent laboratory to study the formation of solar-mass stars in a low-metallicity environment, similar to the conditions expected in the early phases of...
Discovery of an Edge-On Disk in the MBM 12 Young Association (2002)
Jayawardhana, Ray, Luhman, K. L., D'Alessio, Paola, Stauffer, John R.
We report the discovery of a spatially-resolved edge-on protoplanetary disk in the ~2-Myr-old MBM 12 young association. Our near-infrared images of LkHa 263C (MBM 12A 3C), obtained with the Hokupa'a...
New sub-millimeter limits on dust in the 55 Cancri planetary system (2002)
Jayawardhana, Ray, Holland, Wayne S., Kalas, Paul, Greaves, Jane S., Dent, William R. F., Wyatt, Mark C., ...
We present new, high-sensitivity sub-millimeter observations towards 55 Cancri, a nearby G8 star with one, or possibly two, known planetary companion(s). Our 850 $\mu$m map, obtained with the SCUBA...
An Adaptive Optics Search for Companions to Stars with Planets (2001)
Luhman, K. L., Jayawardhana, Ray
We have performed a Keck adaptive optics (AO) imaging survey of 25 extrasolar planetary systems discovered by the radial velocity programs. Typically, the high-resolution (FWHM~0.04") near-infrared...
Brandeker, Alexis, Liseau, Rene, Artymowicz, Pawel, Jayawardhana, Ray
Since a majority of young low-mass stars are members of multiple systems, the study of their stellar and disk configurations is crucial to our understanding of both star and planet formation...
Discovery of close companions to the nearby young stars HD 199143 and HD 358623 (2001)
Jayawardhana, Ray, Brandeker, Alexis
Young stellar systems in the solar neighborhood provide valuable laboratories for detailed studies of star and planet formation. The bright F8V star HD 199143 and the Li-rich late-type emission line...
Prospects for Star Formation Studies with Mid-Infrared Instruments on Large Telescopes (2001)
Imaging and spectroscopic observations in the mid-infrared wavelength range (5$\mu$m--30$\mu$m) offer valuable insight into the origins of stars and planets. Sensitive new array detectors on 8-meter...
Evolution of Dusty Disks in Nearby Young Stellar Groups (2001)
Given their proximity and age differences, nearby groups of young stars are valuable laboratories for investigations of disk evolution and diversity. The estimated 10-Myr age of groups like the TW...
Mid-Infrared Imaging of Candidate Vega-Like Systems (2001)
Jayawardhana, Ray, Fisher, R. Scott, Telesco, Charles M., Pina, Robert K., Navascues, David Barrado Y, Hartmann, Lee W., ...
We have conducted deep mid-infrared imaging of a relatively nearby sample of candidate Vega-like stars using the OSCIR instrument on the CTIO 4-meter and Keck II 10-meter telescopes. Our discovery of...
Jayawardhana, Ray, Wolk, Scott J., Navascues, David Barrado Y, Telesco, Charles M., Hearty, Thomas J.
The recent identification of several groups of young stars within 100 parsecs of the Sun has generated widespread interest. Given their proximity and possible age differences, these systems are...
Timescales of Disk Evolution and Planet Formation (2000)
It has been suggested that circumstellar disks evolve from dense, actively accreting structures to low-mass, replenished remnants. During this transition, grains may assemble into planetesimals, or...
Infall models of Class 0 protostars (2000)
Jayawardhana, Ray, Hartmann, Lee, Calvet, Nuria
We have carried out radiative transfer calculations of infalling, dusty envelopes surrounding embedded protostars to understand the observed properties of the recently identified ``Class 0'' sources....
Probing Planet Formation Among Nearby Young Stars (2000)
The recent identification of several groups of young stars within 100 parsecs of the Sun has generated widespread interest. Given their proximity and possible age differences, these systems are...
Marengo, Massimo, Jayawardhana, Ray, Fazio, Giovanni G., Hoffmann, William F., Hora, Joseph L., Dayal, Aditya, ...
Most, if not all, stars are now believed to produce energetic outflows during their formation. Yet, almost 20 years after the discovery of bipolar outflows from young stars, the origins of this...
MBM12: A Younger Version of the TW Hydrae Association? (2000)
Wolk, Scott J., Cover, Rebecca T., Jayawardhana, Ray, Hearty, Thomas J.
We present optical and infrared photometry of stars near the MBM 12 dark cloud. The optical data indicate that there are about 40 candidate pre-main sequence stars in the same area currently occupied...
Groups of young stars located in the solar neighborhood have recently received a lot of attention. These stars, which are $\lesssim$ 10 million years old, can provide insights into the birth of stars...
Dust in the 55 Cancri planetary system (2000)
Jayawardhana, Ray, Holland, Wayne S., Greaves, Jane S., Dent, William R. F., Marcy, Geoffrey W., Hartmann, Lee W., ...
The presence of debris disks around $\sim$ 1-Gyr-old main sequence stars suggests that an appreciable amount of dust may persist even in mature planetary systems. Here we report the detection of dust...
Circumstellar dust :--from protostars to planetary systems /--by Ray Jayawardhana. (2000)
Thesis (Ph. D.)--Harvard University, 2000.
Jayawardhana, Ray, Hartmann, Lee, Fazio, Giovanni, Fisher, R. Scott, Telesco, Charles M., Pina, Robert K.
A group of young, active stars in the vicinity of TW Hydrae has recently been identified as a possible physical association with a common origin. Given its proximity ($\sim$50 pc), age ($\sim$10 Myr)...
The complex protostellar source IRAS 04325+2402 (1999)
Hartmann, Lee, Calvet, Nuria, Allen, Lori, Chen, Hua, Jayawardhana, Ray
We report Hubble Space Telescope near-infrared NICMOS observations of a remarkable low-luminosity Class I (protostellar) source in the Taurus Molecular Cloud. IRAS 04325+2402 exhibits a complex...
Jayawardhana, Ray, Hartmann, Lee, Fazio, Giovanni, Fisher, R. Scott, Telesco, Charles M., Pina, Robert K.
We present high-resolution mid-infrared observations of the nearby late-type young binary system Hen 3-600. The binary, at a distance of $\sim$ 50 pc, could be a member of the TW Hydrae Association,...
Imaging Circumstellar Debris Disks (1998)
I briefly review recent developments in the study of circumstellar debris disks, particularly at infrared and sub-millimeter wavelengths, and discuss possible avenues of research for the near future.
A dust disk surrounding the young A star HR4796A (1998)
Jayawardhana, Ray, Fisher, Scott, Hartmann, Lee, Telesco, Charles, Pina, Robert, Fazio, Giovanni
We report the codiscovery of the spatially-resolved dust disk of the Vega-like star HR 4796A. Images of the thermal dust emission at $\lambda = 18 \mu$m show an elongated structure approximately 200...
Pulse Profiles of Millisecond Pulsars (1996)
Jayawardhana, Ray, Grindlay, Jonathan E.
We present a comparison between the average radio pulse profiles of millisecond pulsars (MSPs) in the field and in globular clusters. Our sample consists of 20 field MSPs and 25 cluster MSPs for...