590 citations · 8.8k across the 153 of their papers we have counts for
156 papers
Exploration of M31 via Black-Hole Slingshots and the "Intergalactic Imperative"
Andrew Gould
I show that a gravitational slingshot using a stellar-mass black hole (BH) orbiting SgrA* could launch robotic spacecraft toward M31 at , a speed that is ultimately limited…
MASADA: From Microlensing Planet Mass-Ratio Function to Planet Mass Function
Andrew Gould
Using current technology, gravitational microlensing is the only method that can measure planet masses over the full parameter space of planet and stellar-host masses and at a broa…
KMT-2021-BLG-0912Lb: A microlensing super Earth around a K-type star
Cheongho Han, Ian A. Bond, Jennifer C. Yee +55
The light curve of the microlensing event KMT-2021-BLG-0912 exhibits a very short anomaly relative to a single-lens single-source form. We investigate the light curve for the purpo…
Masses for Free-Floating Planets and Dwarf Planets
Andrew Gould, Weicheng Zang, Shude Mao +1
The mass and distance functions of free-floating planets (FFPs) would give major insights into the formation and evolution of planetary systems, including any systematic difference…
Rigorous "Rich Argument" in Microlensing Parallax
Andrew Gould
I show that when the observables are well measured up to a discrete degeneracy in the microlensing parallax vector $\vec π_{\rm…
The Separation Distribution of Ultra-Wide Binaries across Galactic Populations
Hai-Jun Tian, Kareem El-Badry, Hans-Walter Rix +1
We present an extensive sample of ultra-wide binary stars in the solar neighborhood, focusing on separations of . Using data from Gaia DR2, we define kinematic sub-p…
Osculating Versus Intersecting Circles in Space-Based Microlens Parallax Degeneracies
Andrew Gould
I investigate the origin of arc degeneracies in satellite microlens parallax pi_E measurements with only late time data, e.g., t > t0 + t_E as seen from the satellite. I show that…
Spitzer Microlensing parallax reveals two isolated stars in the Galactic bulge
Weicheng Zang, Yossi Shvartzvald, Tianshu Wang +90
We report the mass and distance measurements of two single-lens events from the 2017 Spitzer microlensing campaign. The ground-based observations yield the detection of finite-sour…
Spitzer Microlensing of MOA-2016-BLG-231L : A Counter-Rotating Brown Dwarf Binary in the Galactic Disk
Sun-Ju Chung, Andrew Gould, Jan Skowron +60
We analyze the binary microlensing event MOA-2016-BLG-231, which was observed from the ground and from Spitzer. The lens is composed of very low-mass brown dwarfs (BDs) with $M_1 =…
KMT-2017-BLG-0165Lb: A Super-Neptune mass planet Orbiting a Sun-like Host Star
Youn Kil Jung, Andrew Gould, Weicheng Zang +22
We report the discovery of a low mass-ratio planet , i.e., 2.5 times higher than the Neptune/Sun ratio. The planetary system was discovered from the analysi…
Gaia: Orion's Integral Shaped Filament is a Standing Wave
Amelia M. Stutz, Valentina I. Gonzalez-Lobos, Andrew Gould
The Integral Shaped Filament (ISF) is the nearest molecular cloud with rapid star formation, including massive stars, and it is therefore a star-formation laboratory. We use Gaia p…
A Distant Sample of Halo Wide Binaries from SDSS
Johanna Coronado, María Paz Sepúlveda, Andrew Gould +1
Samples of reliably identified halo wide binaries are scarce. If reasonably free from selection effects and with a small degree of contamination by chance alignments, these wide bi…
A Universal Break in the Planet-to-Star Mass-Ratio Function of Kepler MKG stars
Ilaria Pascucci, Gijs D. Mulders, Andrew Gould +1
We follow the microlensing approach and quantify the occurrence of Kepler exoplanets as a function of planet-to-star mass ratio, q, rather than planet radius or mass. For planets w…
Two chemically similar stellar overdensities on opposite sides of the plane of the Galaxy
Maria Bergemann, Branimir Sesar, Judith G. Cohen +9
Our Galaxy is thought to have undergone an active evolutionary history dominated by star formation, the accretion of cold gas, and, in particular, mergers up to 10 gigayear ago. Th…
KELT-20b: A giant planet with a period of P~ 3.5 days transiting the V~ 7.6 early A star HD 185603
Michael B. Lund, Joseph E. Rodriguez, George Zhou +46
We report the discovery of KELT-20b, a hot Jupiter transiting a V~7.6 early A star with an orbital period of P~3.47 days. We identified the initial transit signal in KELT-North sur…
A giant planet undergoing extreme ultraviolet irradiation by its hot massive-star host
B. Scott Gaudi, Keivan G. Stassun, Karen A. Collins +57
The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extra-solar planets now known,…
TGAS Error Renormalization from the RR Lyrae Period-Luminosity Relation
Andrew Gould, Juna A. Kollmeier, Branimir Sesar
The Gaia team has applied a renormalization to their internally-derived parallax errors $$ σ_{tgas}(π) = \sqrt{[Aσ_{int}(π)]^2 + σ_0^2}; \ \ \ \ (A,σ_0) = (1.4,0.2…
Predicted Information Content of Gaia-Hipparcos
Andrew Gould, Juna A. Kollmeier
The Gaia-Tycho release, scheduled for 14 September, is forecast to yield parallax errors of as for about 2 million Tycho stars. We show analytically that the actua…
Gaia Parallax Zero Point From RR Lyrae Stars
Andrew Gould, Juna A. Kollmeier
Like Hipparcos, Gaia is designed to give absolute parallaxes, independent of any astrophysical reference system. And indeed, Gaia's internal zero-point error for parallaxes is like…
KELT-12b: A Day, Highly Inflated Hot Jupiter Transiting a Mildly Evolved Hot Star
Daniel J. Stevens, Karen A. Collins, B. Scott Gaudi +46
We report the discovery of KELT-12b, a highly inflated Jupiter-mass planet transiting a mildly evolved host star. We identified the initial transit signal in the KELT-North survey…
KELT-16b: A highly irradiated, ultra-short period hot Jupiter nearing tidal disruption
Thomas E. Oberst, Joseph E. Rodriguez, Knicole D. Colón +47
We announce the discovery of KELT-16b, a highly irradiated, ultra-short period hot Jupiter transiting the relatively bright () star TYC 2688-1839-1. A global analysis of…
KELT-17b: A hot-Jupiter transiting an A-star in a misaligned orbit detected with Doppler tomography
George Zhou, Joseph E. Rodriguez, Karen A. Collins +45
We present the discovery of a hot-Jupiter transiting the V=9.23 mag main-sequence A-star KELT-17 (BD+14 1881). KELT-17b is a 1.31 -0.29/+0.28 Mj, 1.525 -0.060/+0.065 Rj hot-Jupiter…
Microlensing by Kuiper, Oort, and Free-Floating Planets
Andrew Gould
Microlensing is generally thought to probe planetary systems only out to a few Einstein radii. Microlensing events generated by bound planets beyond about 10 Einstein radii general…
Slingshot Mechanism in Orion: Kinematic Evidence For Ejection of Protostars by Filaments
Amelia M. Stutz, Andrew Gould
By comparing 3 constituents of Orion A (gas, protostars, and pre-main-sequence stars), both morhologically and kinematically, we derive the following. The gas surface density near…