Rogers, Justin C., Apai, Daniel, Lopez-Morales, Mercedes, Sing, David K., Burrows, Adam
We report the detection in Ks-band of the secondary eclipse of the hot Jupiter CoRoT-1b, from time series photometry with the ARC 3.5-m telescope at Apache Point Observatory. The eclipse shows a...
Eclipsing Binary Stars as Tests of Stellar Evolutionary Models and Stellar Ages (2009)
Stassun, Keivan G., Hebb, Leslie, Lopez-Morales, Mercedes, Prsa, Andrej
Eclipsing binary stars provide highly accurate measurements of the fundamental physical properties of stars. They therefore serve as stringent tests of the predictions of evolutionary models upon...
Ground-based secondary eclipse detection of the very-hot Jupiter OGLE-TR-56b (2009)
Sing, David K., Lopez-Morales, Mercedes
We report on the detection of the secondary eclipse of the very-hot Jupiter OGLE-TR-56b from combined z-band time series photometry obtained with the VLT and Magellan telescopes. We measure a flux...
Low Mass Companions for Five Solar-Type Stars from the Magellan Planet Search Program (2008)
Minniti, Dante, Butler, R. Paul, Lopez-Morales, Mercedes, Shectman, Stephen A., Adams, Fred C., Arriagada, Pamela, ...
We report low mass companions orbiting five Solar-type stars that have emerged from the Magellan precision Doppler velocity survey, with minimum (Msini) masses ranging from 1.2 to 25 Mjup. These...
Fundamental Properties of Low-Mass Stars and Brown Dwarfs (2008)
Liu, Michael C., Stassun, Keivan G., Allard, France, Blake, Cullen H., Bonnefoy, M., Cody, Ann Marie, ...
Precise measurements of the fundamental properties of low-mass stars and brown dwarfs are key to understanding the physics underlying their formation and evolution. While there has been great...
Coughlin, Jeffrey L., Stringfellow, Guy S., Becker, Andrew C., Lopez-Morales, Mercedes, Mezzalira, Fabio, Krajci, Tom
We present ground-based observations of the transiting Neptune-mass planet Gl 436b obtained with the 3.5-meter telescope at Apache Point Observatory and other supporting telescopes. Included in this...
How eccentric orbital solutions can hide planetary systems in 2:1 resonant orbits (2008)
Anglada-Escude, Guillem, Lopez-Morales, Mercedes, Chambers, John E.
The Doppler technique measures the reflex radial motion of a star induced by the presence of companions and is the most successful method to detect exoplanets. If several planets are present, their...
Two Jupiter-Mass Planets Orbiting HD 154672 and HD 205739 (2008)
Lopez-Morales, Mercedes, Butler, R. Paul, Fischer, Debra A., Minniti, Dante, Shectman, Stephen A., Takeda, Genya, ...
We report the detection of the first two planets from the N2K Doppler planet search program at the Magellan telescopes. The first planet has a mass of M sin i = 4.96 M_Jup and is orbiting the G3 IV...
Spitzer 24 μm time series observations of the eclipsing M dwarf binary GU Boötis (2008)
Von Braun, Kaspar, Van Belle, Gerard T., Ciardi, David R., Lopez-Morales, Mercedes, Hoard, D. W., Wachter, Stefanie
We present a set of Spitzer 24 μm MIPS time series observations of the M dwarf eclipsing binary star GU Boötis. Our data cover three secondary eclipses of the system: two consecutive events and an...
'Slow' and Fast Rotators among Hypervelocity Stars (2008)
Lopez-Morales, Mercedes, Bonanos, Alceste Z.
We measure the projected rotational velocities of the late B-type hypervelocity stars HVS7 and HVS8 from high resolution spectroscopy to be 60 +/- 17 km/s and 260 +/- 70 km/s. The 'slow' rotation of...
Spitzer 24-micron Time-Series Observations of the Eclipsing M-dwarf Binary GU Bootis (2007)
Von Braun, Kaspar, Van Belle, Gerard T., Ciardi, David R., Lopez-Morales, Mercedes, Hoard, D. W., Wachter, Stefanie
We present a set of {\it Spitzer} 24$\mu$m MIPS time series observations of the M-dwarf eclipsing binary star GU Bo\"otis. Our data cover three secondary eclipses of the system: two consecutive...
Low Metallicity Indicates that the Hypervelocity Star HE 0437-5439 was Ejected from the LMC (2007)
Bonanos, Alceste Z., Lopez-Morales, Mercedes, Hunter, Ian, Ryans, Robert S. I.
We measure the metallicity of the unusual hypervelocity star HE 0437-5439 from high resolution spectroscopy to be half-solar. We determine a spectral type of B2 IV-III for the star and derive an...
Lopez-Morales, Mercedes, Seager, Sara
Very hot Jupiters (VHJs) are defined as Jupiter-mass extrasolar planets with orbital periods shorter than three days. For low albedos the effective temperatures of irradiated VHJs can reach 2500-3000...
The Spitzer 24-micron Photometric Light Curve of the Eclipsing M-dwarf Binary GU Bootis (2007)
Von Braun, Kaspar, Van Belle, Gerard T., Ciardi, David, Lopez-Morales, Mercedes, Hoard, D. W., Wachter, Stefanie
We present a carefully controlled set of Spitzer 24 \micron MIPS time series observations of the low mass eclipsing binary star GU Bo\"otis (GU Boo). Our data cover three secondary eclipses of the...
The recent burst in the number of radii measurements of very low-mass stars from eclipsing binaries and interferometry of single stars has opened more questions about what can be causing the...
NSVS01031772: A New 0.50+0.54 Msun Detached Eclipsing Binary (2006)
Lopez-Morales, Mercedes, Orosz, Jerome A., Shaw, J. Scott, Havelka, Lauren, Arevalo, Maria Jesus, McIntyre, Travis, ...
We report the discovery of a new detached eclipsing binary known as NSVS01031772 with component masses M_1= 0.5428 +/- 0.0027Msun, M_2= 0.4982 +/- 0.0025Msun, and radii R_1= 0.5260 +/- 0.0028Rsun,...
Limits to Transits of the Neptune-mass planet orbiting Gl 581 (2006)
Lopez-Morales, Mercedes, Morrell, Nidia I., Butler, R. Paul, Seager, Sara
We have monitored the Neptune-mass exoplanet-hosting M-dwarf Gl 581 with the 1m Swope Telescope at Las Campanas Observatory over two predicted transit epochs. A neutral density filter centered at...
Lee, Jae-Woo, Lopez-Morales, Mercedes, Carney, Bruce W.
We report the abundance analysis of one red giant branch star in the metal-poor outer halo globular cluster NGC 5694. We obtain [Fe/H] = -1.93, based on the ionized lines, and our metallicity...
A Chemical Abundance Study of three RHB and two RGB stars in NGC6637 (M69) (2006)
Lee, Jae-Woo, Lopez-Morales, Mercedes
We present a detailed chemical abundance study of three red horizontal branch and two red giant branch stars in the metal-rich globular cluster NGC 6637 (M69). The value of [Fe/H] derived from LTE...
Very Cool Close Binaries (2006)
Shaw, J. Scott, Lopez-Morales, Mercedes
We present new observations of cool
Testing Low-Mass Stellar Models: Three New Detached Eclipsing Binaries below 0.75 Msun (2006)
Lopez-Morales, Mercedes, Shaw, J. Scott
Full tests to stellar models below 1 Msun have been hindered until now by the scarce number of precise measurements of the stars' most fundamental parameters: their masses and radii. With the current...
This paper summarizes a three night observing campaign aimed at achieving milli-magnitude precision photometry of bright stars (V < 9.0) with the 1-meter Swope telescope at Las Campanas Observatory....