Search Publications
Estimating Distances from Parallaxes. V. Geometric and Photogeometric Distances to 1.47 Billion Stars in Gaia Early Data Release 3
Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M. +2 more
Stellar distances constitute a foundational pillar of astrophysics. The publication of 1.47 billion stellar parallaxes from Gaia is a major contribution to this. Despite Gaia's precision, the majority of these stars are so distant or faint that their fractional parallax uncertainties are large, thereby precluding a simple inversion of parallax to …
New Determinations of the UV Luminosity Functions from z 9 to 2 Show a Remarkable Consistency with Halo Growth and a Constant Star Formation Efficiency
Oesch, P. A.; Bouwens, R. J.; Reddy, N. +9 more
Here we provide the most comprehensive determinations of the rest-frame UV luminosity function (LF) available to date with the Hubble Space Telescope (HST) at z ~ 2-9. Essentially all of the noncluster extragalactic legacy fields are utilized, including the Hubble Ultra Deep Field, the Hubble Frontier Fields parallel fields, and all five CANDELS f…
The JPL Planetary and Lunar Ephemerides DE440 and DE441
Park, Ryan S.; Folkner, William M.; Williams, James G. +1 more
The planetary and lunar ephemerides called DE440 and DE441 have been generated by fitting numerically integrated orbits to ground-based and space-based observations. Compared to the previous general-purpose ephemerides DE430, seven years of new data have been added to compute DE440 and DE441, with improved dynamical models and data calibration. Th…
The Automatic Learning for the Rapid Classification of Events (ALeRCE) Alert Broker
Bauer, F. E.; Moya, A.; Catelan, M. +40 more
We introduce the Automatic Learning for the Rapid Classification of Events (ALeRCE) broker, an astronomical alert broker designed to provide a rapid and self-consistent classification of large etendue telescope alert streams, such as that provided by the Zwicky Transient Facility (ZTF) and, in the future, the Vera C. Rubin Observatory Legacy Surve…
The HETDEX Instrumentation: Hobby-Eberly Telescope Wide-field Upgrade and VIRUS
Schneider, Donald P.; Marshall, J. L.; Janowiecki, Steven +46 more
The Hobby-Eberly Telescope (HET) Dark Energy Experiment (HETDEX) is undertaking a blind wide-field low-resolution spectroscopic survey of 540 deg2 of sky to identify and derive redshifts for a million Lyα-emitting galaxies in the redshift range 1.9 < z < 3.5. The ultimate goal is to measure the expansion rate of the universe at th…
Constraining the Nature of the PDS 70 Protoplanets with VLTI/GRAVITY
Lutz, D.; Genzel, R.; Sturm, E. +101 more
We present K-band interferometric observations of the PDS 70 protoplanets along with their host star using VLTI/GRAVITY. We obtained K-band spectra and 100 µas precision astrometry of both PDS 70 b and c in two epochs, as well as spatially resolving the hot inner disk around the star. Rejecting unstable orbits, we found a nonzero eccentricit…
On the Diversity of Asymmetries in Gapped Protoplanetary Disks
Dong, Ruobing; Garufi, Antonio; Sallum, Steph +7 more
Protoplanetary disks with large inner dust cavities are thought to host massive planetary or substellar companions. These disks show asymmetries and rings in the millimeter continuum caused by dust trapping in pressure bumps and potentially vortices or horseshoes. The origin of the asymmetries and their diversity remains unclear. We present a comp…
orvara: An Efficient Code to Fit Orbits Using Radial Velocity, Absolute, and/or Relative Astrometry
Dupuy, Trent J.; Bardalez Gagliuffi, Daniella C.; Brandt, Timothy D. +5 more
We present an open-source Python package, Orbits from Radial Velocity, Absolute, and/or Relative Astrometry (orvara), to fit Keplerian orbits to any combination of radial velocity, relative astrometry, and absolute astrometry data from the Hipparcos-Gaia Catalog of Accelerations. By combining these three data types, one can measure precise masses …
Where Is the Water? Jupiter-like C/H Ratio but Strong H2O Depletion Found on τ Boötis b Using SPIRou
Vandal, Thomas; Doyon, René; Donati, Jean-François +18 more
The present-day envelope of gaseous planets is a relic of how these giant planets originated and evolved. Measuring their elemental composition therefore presents a powerful opportunity to answer long-standing questions regarding planet formation. Obtaining precise observational constraints on the elemental inventory of giant exoplanets has, howev…
Photometric Study and Absolute Parameter Estimation of Six Totally Eclipsing Contact Binaries
Guo, Ya-Ni; Li, Kai; Xia, Qi-Qi +6 more
High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429 Cam), while the others are W-type contact ones. By analyzing the times of light minima, we discovered that two of them exhibit secular period increase while three manifest long-te…