590 citations · 8.8k across the 153 of their papers we have counts for
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Sgr A* ``Visual Binaries'': A Direct Measurement of the Galactocentric Distance
Samir Salim, Andrew Gould
We present a new geometrical method for measuring the distance to the Galactic center (R_0) by solving for the Keplerian orbit of individual stars bound to the black hole associate…
Correlated errors in Hipparcos parallaxes towards the Pleiades and the Hyades
Vijay K. Narayanan, Andrew Gould
We show that the errors in the Hipparcos parallaxes towards the Pleiades and the Hyades open clusters are spatially correlated over angular scales of 2 to 3 deg, with an amplitude…
Complete Parallax and Proper Motion Solutions For Halo Binary-Lens Microlensing Events
Andrew Gould, Nikolay Andronov
A major problem in the interpretation of microlensing events is that the only measured quantity, the Einstein time scale t_E, is a degenerate combination of the three quantities on…
Anomaluos RR Lyrae (V-I)_0 colors in Baade's Window
Amelia Stutz, Piotr Popowski, Andrew Gould
We compare (V-I)_0-(V-K)_0 color-color and (V-I)_0-log P period-color diagrams for Baade's Window and local RRab Lyrae stars. We find that for a fixed log P the Baade's Window RR L…
The RR Lyrae Distance Scale
Piotr Popowski, Andrew Gould
We review seven methods of measuring the absolute magnitude M_V of RR Lyrae stars in light of the Hipparcos mission and other recent developments. We focus on identifying possible…
A Precision test of Hipparcos systematics towards the Hyades
Vijay K. Narayanan, Andrew Gould
We propose and apply a test that can detect any systematic errors in the Hipparcos parallaxes towards the Hyades cluster at the level of 0.3 mas. We show that the statistical paral…
Optimal Microlensing Observations
Andrew Gould
One of the major limitations of microlensing observations toward the Large Magellanic Cloud (LMC) is the low rate of event detection. What can be done to improve this rate? Is it b…
Microlens Parallaxes with SIRTF
Andrew Gould
The Space Infrared Telescope Facility (SIRTF) will drift away from the Earth at about 0.1 AU/yr. Microlensing events will therefore have different characteristics as seen from the…
Systematics of RR Lyrae Statistical Parallax III: Apparent Magnitudes and Extinctions
Andrew Gould, Piotr Popowski
We sing the praises of the central limit theorem. Having previously removed all other possible causes of significant systematic error in the statistical parallax determination of R…
Isolating Red Giant Stars in M31's Elusive Outer Spheroid
David B. Reitzel, Puragra Guhathakurta, Andrew Gould
Deep UBRI images of a 15'x15' field in the M31 galaxy's outer spheroid obtained with the KPNO 4-m telescope, and Keck 10-m telescope+LRIS I-band images, are used to isolate candida…
Microlens Parallax Asymmetries Toward the LMC
Andrew Gould
If the microlensing events now being detected toward the Large Magellanic Cloud (LMC) are due to lenses in the Milky Way halo, then the events should typically have asymmetries of…
No Death Star -- For Now
Jay A. Frogel, Andrew Gould
A star passing within $\sim 10^4 \au$ of the Sun would trigger a comet shower that would reach the inner solar system about 0.18 Myr later. We calculate a prior probability of ~0.4…