Search Publications
ACCESS: A Visual to Near-infrared Spectrum of the Hot Jupiter WASP-43b with Evidence of H2O, but No Evidence of Na or K
Kirk, James; López-Morales, Mercedes; Alam, Munazza K. +11 more
We present a new ground-based visual transmission spectrum of the hot Jupiter WASP-43b, obtained as part of the ACCESS Survey. The spectrum was derived from four transits observed between 2015 and 2018, with combined wavelength coverage between 5300 and 9000 Å and an average photometric precision of 708 ppm in 230 Å bins. We perform an atmospheric…
New Beta Cephei Stars from the KELT Project
Pepper, Joshua; Stassun, Keivan G.; Siverd, Robert J. +9 more
We present the results of a search for Galactic β Cephei stars, which are massive pulsating stars with both pressure modes and mixed modes. Thus, these stars can serve as benchmarks for seismological studies of the interiors of massive stars. We conducted the search by performing a frequency analysis on the optical light curves of known O- and B-t…
Discovery of Extended Tidal Tails around the Globular Cluster Palomar 13
Price-Whelan, Adrian M.; Mateu, Cecilia; Drlica-Wagner, Alex +2 more
We use photometry from the DECam Legacy Survey to detect candidate tidal tails extending ∼5° on either side of the Palomar 13 globular cluster. The tails are aligned with the proper motion of Palomar 13 and are consistent with its old, metal-poor stellar population. We identify three RR Lyrae stars (RRLs) that are plausibly associated with the tai…
Probing the Evolutionary History of Comets: An Investigation of the Hypervolatiles CO, CH4, and C2H6 in the Jupiter-family Comet 21P/Giacobini-Zinner
Feaga, Lori M.; Cochran, Anita L.; Vervack, Ronald J., Jr. +13 more
Understanding the cosmogonic record encoded in the parent volatiles stored in cometary nuclei requires investigating whether evolution (thermal or otherwise) has modified the composition of short-period comets during successive perihelion passages. As the most volatile molecules systematically observed in comets, the abundances of CO, CH4
An Increase in Small-planet Occurrence with Metallicity for Late-type Dwarf Stars in the Kepler Field and Its Implications for Planet Formation
Cheng, Sihao; Schlaufman, Kevin C.; Lu, Cicero X.
While it is well-established that giant-planet occurrence rises rapidly with host star metallicity, it is not yet clear if small-planet occurrence around late-type dwarf stars depends on host star metallicity. Using the Kepler Data Release 25 planet candidate list and its completeness data products, we explore planet occurrence as a function of me…
Uranus in Northern Midspring: Persistent Atmospheric Temperatures and Circulations Inferred from Thermal Imaging
Fletcher, Leigh N.; Irwin, Patrick G. J.; Orton, Glenn S. +2 more
We present results from mid-infrared imaging of Uranus at wavelengths of 13.0 and 18.7 µm, sensing emission from the stratosphere and upper troposphere, acquired using the VISIR instrument at the Very Large Telescope, 2018 September 4-October 20. Using a combination of inverse and forward modeling, we analyze these northern midspring (L
Binary Stars in Upper Scorpius
Tokovinin, Andrei; Briceño, Cesar
To address the statistics of binary stars in the 8 Myr old Upper Scorpius (USco) star formation region, we conducted a speckle interferometric survey of 614 association members more massive than 0.4 {{ \mathcal M }}⊙ (spectral types earlier than M3V) based on the list of Luhman et al. (2018). We resolved 187 pairs, 55 of which are new …
Cloud Atlas: Weak Color Modulations Due to Rotation in the Planetary-mass Companion GU Psc b and 11 Other Brown Dwarfs
Schneider, Glenn; Apai, Dániel; Marley, Mark +10 more
Among the greatest challenges in understanding ultracool brown dwarf and exoplanet atmospheres is the evolution of cloud structure as a function of temperature and gravity. In this study, we present the rotational modulations of GU Psc b—a rare mid-T spectral type planetary-mass companion at the end of the L/T spectral type transition. Based on th…
Searching for ZZ Ceti White Dwarfs in the Gaia Survey
Bergeron, P.; Vincent, Olivier; Lafrenière, David
The Gaia satellite recently released parallax measurements for ∼260,000 high-confidence white dwarf candidates, allowing for precise measurements of their physical parameters. By combining these parallaxes with Pan-STARRS and u-band photometry, we measured the effective temperature and stellar mass for all white dwarfs in the Northern Hemisphere w…
Evidence of Systematic Errors in Spitzer Microlens Parallax Measurements
Bennett, David P.; Koshimoto, Naoki
The microlensing parallax campaign with the Spitzer space telescope aims to measure masses and distances of microlensing events seen toward the Galactic bulge, with a focus on planetary microlensing events. The hope is to measure how the distribution of planets depends on position within the Galaxy. In this paper, we compare 50 microlens parallax …