MMT Hypervelocity Star Survey (2008)
Brown, Warren R., Geller, Margaret J., Kenyon, Scott J.
We describe a new survey for unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their most likely origin. We...
Currie, Thayne, Plavchan, Peter, Kenyon, Scott J.
We describe Spitzer IRAC and MIPS observations of the nearby 25 Myr-old open cluster NGC 2232. Combining these data with ROSAT All-Sky Survey observations, proper motions, and optical...
Kenyon, Scott J., Bromley, Benjamin C.
We describe calculations for the formation of icy planets and debris disks at 30-150 AU around 1-3 solar mass stars. Debris disk formation coincides with the formation of planetary systems. As...
Planet formation around stars of various masses: Hot super-Earths (2008)
Kennedy, Grant M., Kenyon, Scott J.
We consider trends resulting from two formation mechanisms for short-period super-Earths: planet-planet scattering and migration. We model scenarios where these planets originate near the snow line...
Brown, Warren R., Beers, Timothy C., Wilhelm, Ronald, Prieto, Carlos Allende, Geller, Margaret J., Kenyon, Scott J., ...
We present a complete spectroscopic survey of 2414 2MASS-selected blue horizontal branch (BHB) candidates selected over 4300 deg^2 of the sky. We identify 655 BHB stars in this non-kinematically...
Kennedy, Grant M., Kenyon, Scott J.
We use a semi-analytic circumstellar disk model that considers movement of the snow line through evolution of accretion and the central star to investigate how gas giant frequency changes with...
Brown, Warren R., Geller, Margaret J., Kenyon, Scott J., Kurtz, Michael J., Bromley, Benjamin C.
We report the discovery of 3 new unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their only suggested...
Terrestrial Zone Debris Disk Candidates in h and chi Persei (2007)
Currie, Thayne, Kenyon, Scott J., Rieke, George, Balog, Zoltan, Bromley, Benjamin C.
We analyze 8 sources with strong mid-infrared excesses in the 13 Myr-old double cluster h and chi Persei. New optical spectra and broadband SEDs (0.36-8 mu_m) are consistent with cluster membership....
Stellar Velocity Dispersion of the Leo A Dwarf Galaxy (2007)
Brown, Warren R., Geller, Margaret J., Kenyon, Scott J., Kurtz, Michael J.
We measure the first stellar velocity dispersion of the Leo A dwarf galaxy, \sigma = 9.3 +- 1.3 km/s. We derive the velocity dispersion from the radial velocities of ten young B supergiants and two...
Formation and Collisional Evolution of Kuiper Belt Objects (2007)
Kenyon, Scott J., Bromley, Benjamin C., O'Brien, David P., Davis, Donald R.
This chapter summarizes analytic theory and numerical calculations for the formation and collisional evolution of KBOs at 20--150 AU. We describe the main predictions of a baseline self-stirring...
Hypervelocity Stars II. The Bound Population (2007)
Brown, Warren R., Geller, Margaret J., Kenyon, Scott J., Kurtz, Michael J., Bromley, Benjamin C.
Hypervelocity stars (HVSs) are stars ejected completely out of the Milky Way by three-body interactions with the massive black hole in the Galactic center. We describe 643 new spectroscopic...
SDSS 0809+1729: Connections Between Extremely Metal Poor Galaxies and Gamma Ray Burst Hosts (2006)
Kewley, Lisa J., Brown, Warren R., Geller, Margaret J., Kenyon, Scott J., Kurtz, Michael J.
We discuss the serendipitous discovery of an extremely metal poor galaxy, SDSS 0809+1729, classified as a star in the Sloan Digital Sky Survey (SDSS). The galaxy has a redshift z = 0.0441 and a...
Planet formation around low mass stars: the moving snow line and super-Earths (2006)
Kennedy, Grant M., Kenyon, Scott J., Bromley, Benjamin C.
We develop a semi-analytic model for planet formation during the pre-main sequence contraction phase of a low mass star. During this evolution, the stellar magnetosphere maintains a fixed ratio...
Hypervelocity Stars: Predicting the Spectrum of Ejection Velocities (2006)
Bromley, Benjamin C., Kenyon, Scott J., Geller, Margaret J., Barcikowski, Elliott, Brown, Warren R., Kurtz, Michael J.
The disruption of binary stars by the tidal field of the black hole in the Galactic Center can produce the hypervelocity stars observed in the halo. We use numerical models to simulate the full...
Infrared Properties of Close Pairs of Galaxies (2006)
Geller, Margaret J., Kenyon, Scott J., Barton, Elizabeth J., Jarrett, Thomas H., Kewley, Lisa J.
We discuss spectroscopy and infrared photometry for a complete sample of ~ 800 galaxies in close pairs objectively selected from the CfA2 redshift survey. We use 2MASS to compare near infrared...
X-Ray Emitting Blast Wave from the Recurrent Nova RS Ophiuchi (2006)
Sokoloski, J. L., Luna, G. J. M., Mukai, K., Kenyon, Scott J.
Stellar explosions such as novae and supernovae produce most of the heavy elements in the Universe. Although the onset of novae from runaway thermonuclear fusion reactions on the surface of a white...
Hypervelocity Stars. I. The Spectroscopic Survey (2006)
Brown, Warren R., Geller, Margaret J., Kenyon, Scott J., Kurtz, Michael J.
We discuss our targeted search for hypervelocity stars (HVSs), stars traveling with velocities so extreme that dynamical ejection from a massive black hole is their only suggested origin. Our survey,...
A Hybrid N-body--Coagulation Code for Planet Formation (2006)
Bromley, Benjamin C., Kenyon, Scott J.
We describe a hybrid algorithm to calculate the formation of planets from an initial ensemble of planetesimals. The algorithm uses a coagulation code to treat the growth of planetesimals into...
A Successful Targeted Search for Hypervelocity Stars (2006)
Brown, Warren R., Geller, Margaret J., Kenyon, Scott J., Kurtz, Michael J.
Hypervelocity stars (HVSs) travel with velocities so extreme that dynamical ejection from a massive black hole is their only suggested origin. Following our discovery of the first HVS, we have...
Brown, Warren R., Geller, Margaret J., Kenyon, Scott J., Kurtz, Michael J., Prieto, Carlos Allende, Beers, Timothy C., ...
We discuss a 175 deg^2 spectroscopic survey for blue horizontal branch (BHB) stars in the Galactic halo. We use the Two Micron All Sky Survey (2MASS) and the Sloan Digital Sky Survey (SDSS) to select...
Terrestrial Planet Formation I. The Transition from Oligarchic Growth to Chaotic Growth (2005)
Kenyon, Scott J., Bromley, Benjamin C.
We use a hybrid, multiannulus, n-body-coagulation code to investigate the growth of km-sized planetesimals at 0.4-2 AU around a solar-type star. After a short runaway growth phase, protoplanets with...
Prospects for Detection of Catastrophic Collisions in Debris Disks (2005)
Kenyon, Scott J., Bromley, Benjamin C.
We investigate the prospects for detecting dust from two body collisions during the late stages of planet formation at 1-150 AU. We develop an analytic model to describe the formation of a dusty...
Discovery of an Unbound Hyper-Velocity Star in the Milky Way Halo (2005)
Brown, Warren R., Geller, Margaret J., Kenyon, Scott J., Kurtz, Michael J.
We have discovered a star, SDSS J090745.0+024507, leaving the Galaxy with a heliocentric radial velocity of +853+-12 km/s, the largest velocity ever observed in the Milky Way halo. The star is either...
Stellar encounters as the origin of distant solar system objects in highly eccentric orbits (2004)
Kenyon, Scott J., Bromley, Benjamin C.
The discovery of Sedna places new constraints on the origin and evolution of our solar system. Here we investigate the possibility that a close encounter with another star produced the observed edge...
The Size Distribution of Kuiper Belt Objects (2004)
Kenyon, Scott J., Bromley, Benjamin C.
We describe analytical and numerical collisional evolution calculations for the size distribution of icy bodies in the Kuiper Belt. For a wide range of bulk properties, initial masses, and orbital...
Detecting the Dusty Debris of Terrestrial Planet Formation (2004)
Kenyon, Scott J, Bromley, Benjamin C
We use a multiannulus accretion code to investigate debris disks in the terrestrial zone, at 0.7-1.3 AU around a 1 solar mass star. Terrestrial planet formation produces a bright dusty ring of debris...
Collisional Cascades in Planetesimal Disks II. Embedded Planets (2003)
Kenyon, Scott J., Bromley, Benjamin C.
We use a multiannulus planetesimal accretion code to investigate the growth of icy planets in the outer regions of a planetesimal disk. In a quiescent minimum mass solar nebula, icy planets grow to...
Preprint typeset using L A T E X style emulateapj v. 20/04/00 (2003)
Warren R. Brown, Carlos Allende Prieto, Timothy C. Beers, Ronald Wilhelm, Margaret J. Geller, Scott J. Kenyon, ...
The Century Survey Galactic Halo Project is a photometric and spectroscopic survey from which we select relatively blue stars (V R < 0:30 mag) as probes of the Milky Way halo. The Survey strip spans...
Gillespie, Elizabeth Barton, Geller, Margaret J., Kenyon, Scott J.
Galaxy-galaxy interactions rearrange the baryons in galaxies and trigger substantial star formation; the aggregate effects of these interactions on the evolutionary histories of galaxies in the...
Dusty Rings: Signposts of Recent Planet Formation (2002)
Kenyon, Scott J., Bromley, Benjamin C.
Many nearby stars are surrounded by a bright ring or disk of cold dust. Our calculations show that these disks and rings of dust are signposts of recent planet formation. Bright rings appear because...
Spectroscopic survey of the Galactic open cluster NGC 6871 I. New emission line stars (2002)
Balog, Zoltan, Kenyon, Scott J.
We analyze spectra of 44 emission line stars detected in a low resolution optical spectroscopic survey of the galactic open cluster NGC 6871. The survey of 1217 stars is complete to V = 14.9 and...
A Near-Infrared Imaging Survey of Coalsack Globule 2 (2002)
Racca, German, Gomez, Mercedes, Kenyon, Scott J.
We describe a near-infrared imaging survey of Globule 2 in the Coalsack. This Bok globule is the highest density region of this southern hemisphere molecular cloud and is the most likely location for...
Kenyon, Scott J., Groot, Paul J., Benson, Priscilla
We describe new optical photometric and spectroscopic observations of the semi-detached eclipsing binary BG Geminorum. A large change in the amount of Mg I absorption at secondary maximum indicates...
Park, Shinae, Kenyon, Scott J.
We describe near-IR imaging data for a sample of 23 class I sources in the Taurus-Auriga dark clouds. Combining our data with previous photometry, we detect brightness variations of 0.1-0.5 mag in...
Planet Formation in the Outer Solar System (2001)
This paper reviews coagulation models for planet formation in the Kuiper Belt, emphasizing links to recent observations of our and other solar systems. At heliocentric distances of 35-50 AU, single...
Collisional Cascades in Planetesimal Disks I. Stellar Flybys (2001)
Kenyon, Scott J., Bromley, Benjamin C.
We use a new multiannulus planetesimal accretion code to investigate the evolution of a planetesimal disk following a moderately close encounter with a passing star. The calculations include...
Infrared Signatures of Protoplanetary Disk Evolution (2001)
Wood, Kenneth, Lada, C. J., Bjorkman, J. E., Kenyon, Scott J., Whitney, Barbara, Wolff, Michael J.
We investigate the observational signatures of a straightforward evolutionary scenario for protoplanetary disks in which the disk mass of small (50 micron) particles decreases homologously with time,...
Wood, Kenneth, Smith, David, Whitney, Barbara, Stassun, Keivan, Kenyon, Scott J., Wolff, Michael J., ...
Ground based imaging, imaging polarimetry, and recent Hubble Space Telescope WFPC2 and NICMOS images of protostars have revealed very complex scattered light patterns that cannot be entirely...
H-Band and Spectroscopic Properties of Abell 1644 (2001)
Tustin, Aaron W., Geller, Margaret J., Kenyon, Scott J., Diaferio, Antonaldo
We discuss H-band (1.65 micrometer) near-infrared photometry of the central 3x3h^{-2} Mpc^2 of Abell 1644 to a limiting M_H~M^*_H+3 (throughout this paper H_0=100 h km s^{-1} Mpc^{-1}). There are 861...
The Continuing Slow Decline of AG Pegasi (2001)
Kenyon, Scott J., Proga, Daniel, Keyes, Charles D.
We analyze optical and ultraviolet observations of the symbiotic binary AG Pegasi acquired during 1992-97. The bolometric luminosity of the hot component declined by a factor of 2-3 from 1980-1985 to...
A Three Micron Survey of the Chamaeleon I Dark Cloud (2001)
Kenyon, Scott J., Gomez, Mercedes
We describe an L-band photometric survey of 0.5 square deg of the Cha I dark cloud. The survey has a completeness limit of L < 11.0. Our survey detects 124 sources, including all known pre-main...
Barton, Elizabeth J., Geller, Margaret J., Bromley, Benjamin C., Van Zee, Liese, Kenyon, Scott J.
We use optical rotation curves to investigate the R-band Tully-Fisher properties of a sample of 90 spiral galaxies in close pairs. The galaxies follow the Tully-Fisher relation remarkably well, with...
Dynamical Evolution of Protoplanetary Disks (2000)
This paper reviews the theory of protostellar debris disks. After a brief introduction to accretion disk physics, I describe coagulation models of planet formation in the outer regions of...
Gravitational Stirring in Planetary Debris Disks (2000)
Kenyon, Scott J., Bromley, Benjamin C.
We describe gravitational stirring models of planetary debris disks using a new multi-annulus planetesimal evolution code. The current code includes gravitational stirring and dynamical friction;...
The Kuiper Belt and Olbers Paradox (2000)
Kenyon, Scott J., Windhorst, Rogier A.
We investigate the constraints that Olbers Paradox, applied to the Zodiacal Background as measured from space, sets on outer solar system objects. If extended to very faint limits, R = 40--50 mag,...
UV excess galaxies: Wolf-Rayet galaxies (2000)
Brown, Warren R., Kenyon, Scott J., Geller, Margaret J., Fabricant, Daniel G.
We discuss V and R band photometry for 67% of the Sullivan et al. 2000 SA57 ultraviolet-selected galaxy sample. In a sample of 176 UV-selected galaxies, Sullivan et al. 2000 find that 24% have (UV-B)...
Flickering in FU Orionis (1999)
Kenyon, Scott J., Kolotilov, E. A., Ibragimov, M. A., Mattei, J. A.
We analyze new and published optical photometric data of FU Orionis, an eruptive pre-main sequence star. The outburst consists of a 5.5 mag rise at B with an e-folding timescale of roughly 50 days....
Tidally-Triggered Star Formation in Close Pairs of Galaxies (1999)
Barton, Elizabeth J., Geller, Margaret J., Kenyon, Scott J.
We analyze new optical spectra of a sample of 502 galaxies in close pairs and n-tuples, separated by
Forming the Dusty Ring in HR 4796A (1999)
Kenyon, Scott J., Wood, Kenneth, Whitney, Barbara A., Wolff, Michael J.
We describe planetesimal accretion calculations for the dusty ring observed in the nearby A0 star HR 4796A. Models with initial masses of 10-20 times the minimum mass solar nebula produce a ring of...
Accretion in the Early Outer Solar System (1999)
Kenyon, Scott J., Luu, Jane X.
We describe calculations of the evolution of an ensemble of small planetesimals in the outer solar system. In a solar nebula with a mass of several times the Minimum Mass Solar Nebula, objects with...
Accretion in the Early Kuiper Belt II. Fragmentation (1999)
Kenyon, Scott J., Luu, Jane X.
We describe new planetesimal accretion calculations in the Kuiper Belt that include fragmentation and velocity evolution. All models produce two power law cumulative size distributions, N_C propto...
Accretion Disks and Eruptive Phenomena (1999)
This paper describes eruptive phenomena in pre-main sequence stars. The eruptions of FU Orionis stars have much in common with outbursts in other accreting systems, such as dwarf novae and some...
Optical Spectroscopy of Embedded Young Stars in the Taurus-Auriga Molecular Cloud (1998)
Kenyon, Scott J., Brown, David I., Tout, Chris, Berlind, Perry
This paper describes the first optical spectroscopic survey of class I sources (also known as embedded sources and protostars) in the Taurus-Auriga dark cloud. We detect 10 of the 24 known class I...
Accretion in the Early Kuiper Belt I. Coagulation and Velocity Evolution (1998)
Kenyon, Scott J., Luu, Jane X.
We describe planetesimal accretion calculations in the Kuiper Belt. Our evolution code simulates planetesimal growth in a single annulus and includes velocity evolution but not fragmentation. Test...
Illumination in symbiotic binary stars: Non-LTE photoionization models. II. Wind case (1997)
Proga, Daniel, Kenyon, Scott J., Raymond, John C.
We describe a non-LTE photoionization code to calculate the wind structure and emergent spectrum of a red giant wind illuminated by the hot component of a symbiotic binary system. We consider...
We analyze the ultraviolet spectrum of the cataclysmic variable GK Per at maximum light. The flat ultraviolet spectrum in this system requires a truncated inner accretion disk and an unusually flat...