501 research outputs found
Eclipsing binary stars with extreme light curve asymmetries mined from large astronomical surveys
The O’Connell effect is one of the most perplexing challenges in binary studies as it has not been convincingly explained. Furthermore, a simple method to obtain essential parameters for eclipsing binaries exhibiting this effect and to extract information describing the asymmetry in the light curve maxima is needed. We have developed an automated program that characterizes the morphology of light curves by depth of both minima, height of both maxima and curvature outside the eclipses
Simultaneous Estimation of Time Delays and Quasar Structure
We expand our Bayesian Monte Carlo method for analyzing the light curves of
gravitationally lensed quasars to simultaneously estimate time delays and
quasar structure including their mutual uncertainties. We apply the method to
HE1104-1805 and QJ0158-4325, two doubly-imaged quasars with microlensing and
intrinsic variability on comparable time scales. For HE1104-1805 the resulting
time delay of (Delta t_AB) = t_A - t_B = 162.2 -5.9/+6.3 days and accretion
disk size estimate of log(r_s/cm) = 15.7 -0.5/+0.4 at 0.2 micron in the rest
frame are consistent with earlier estimates but suggest that existing methods
for estimating time delays in the presence of microlensing underestimate the
uncertainties. We are unable to measure a time delay for QJ0158-4325, but the
accretion disk size is log(r_s/cm) = 14.9 +/- 0.3 at 0.3 micron in the rest
frame.Comment: 21 pages, 6 figures, submitted to Ap
Spitzer as Microlens Parallax Satellite: Mass Measurement for the OGLE-2014-BLG-0124L Planet and its Host Star
We combine Spitzer and ground-based observations to measure the microlens
parallax vector , and so the mass and distance of
OGLE-2014-BLG-0124L, making it the first microlensing planetary system with a
space-based parallax measurement. The planet and star have masses and and are separated by AU in projection. The main source of uncertainty in all these numbers
(approximately 30%, 30%, and 20%) is the relatively poor measurement of the
Einstein radius , rather than uncertainty in ,
which is measured with 2.5% precision. This compares to 22% based on OGLE data
alone, implying that the Spitzer data provide not only a substantial
improvement in the precision of the measurement but also the
first independent test of a ground-based measurement.Comment: submitted to ApJ, 30 pages, 6 figures, 4 table
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