Search Publications
Substellar Hyades Candidates from the UKIRT Hemisphere Survey
Cushing, Michael C.; Schneider, Adam C.; Faherty, Jacqueline K. +14 more
We have used data from the UKIRT Hemisphere Survey to search for substellar members of the Hyades cluster. Our search recovered several known substellar Hyades members, and two known brown dwarfs that we suggest may be members based on a new kinematic analysis. We uncovered thirteen new substellar Hyades candidates, and obtained near-infrared foll…
Differential Proper Motion Spin of the Hipparcos and Gaia Celestial Reference Frames
Makarov, Valeri V.
The Hipparcos catalog provides the first epoch of the celestial reference frame (CRF) in the optical domain and serves as an indispensable tool to verify and improve the Gaia CRF for the brighter stars (V < 11 mag) and to identify the elusive astrometric binary stars with dim or invisible companions, including long-period exoplanets. The system…
Revising Properties of Planet-Host Binary Systems. II. Apparent Near-Earth-analog Planets in Binaries Are Often Sub-Neptunes
Kraus, Adam L.; Sullivan, Kendall
Identifying rocky planets in or near the habitable zones of their stars (near-Earth analogs) is one of the key motivations of many past and present planet-search missions. The census of near-Earth analogs is important because it informs calculations of the occurrence rate of Earth-like planets, which in turn feed into calculations of the yield of …
Spectroscopy of Candidate Members of the Sco-Cen Complex
Luhman, K. L.; Esplin, T. L.
We present spectroscopy of 285 previously identified candidate members of populations in the Sco-Cen complex, primarily Ophiuchus, Upper Sco, and Lupus. The spectra are used to measure spectral types and diagnostics of youth. We find that 269 candidates exhibit signatures of youth in our spectra or previous data, which is consistent with their mem…
ACCESS: Tentative Detection of H2O in the Ground-based Optical Transmission Spectrum of the Low-density Hot Saturn HATS-5b
Kirk, James; López-Morales, Mercedes; Jordán, Andrés +13 more
We present a precise ground-based optical transmission spectrum of the hot Saturn HATS-5b (T eq = 1025 K), obtained as part of the ACCESS survey with the IMACS multi-object spectrograph mounted on the Magellan Baade Telescope. Our spectra cover the 0.5-0.9 µm region and are the product of five individual transits observed between …
Fragment Dynamics in Active Asteroid 331P/Gibbs
Jewitt, David; Hui, Man-To
We present a dynamical analysis of the fragmented active asteroid 331P/Gibbs. Using archival images taken by the Hubble Space Telescope from 2015 to 2018, we measured the astrometry of the primary and the three brightest (presumably the largest) components. Conventional orbit determination revealed a high degree of orbital similarity between the c…
The Interferometric Binary ϵ Cnc in Praesepe: Precise Masses and Age
Klement, Robert; Monnier, John D.; Schaefer, Gail H. +16 more
We observe the brightest member of the Praesepe cluster, ϵ Cnc, to precisely measure the characteristics of the stars in this binary system, en route to a new measurement of the cluster's age. We present spectroscopic radial velocity measurements and interferometric observations of the sky-projected orbit to derive the masses, which we find to be …
Constraining the Size of the Circumgalactic Medium Using the Transverse Autocorrelation Function of C IV Absorbers in Paired Quasar Spectra
Martin, Crystal L.; Rafelski, Marc; Jorgenson, Regina A. +6 more
The circumgalactic medium (CGM) plays a vital role in the formation and evolution of galaxies, acting as a lifeline between galaxies and the surrounding intergalactic medium. In this study, we leverage a unique sample of quasar pairs to investigate the properties of the CGM with absorption line tomography. We present a new sample of medium-resolut…
A New Third Planet and the Dynamical Architecture of the HD 33142 Planetary System
Trifonov, Trifon; Stock, Stephan; Henning, Thomas +24 more
Based on recently-taken and archival HARPS, FEROS, and HIRES radial velocities (RVs), we present evidence for a new planet orbiting the first ascent red giant star HD 33142 (with an improved mass estimate of M1.52 ± 0.03 M ⊙), already known to host two planets. We confirm the Jovian-mass planets HD 33142b and c, with periods of P b…
On the Same Wavelength as the Space Telescope Imaging Spectrograph
Ayres, Thomas R.
The Hubble Space Telescope Imaging Spectrograph (STIS) is a powerful tool for high spectral resolution ultraviolet (UV; 1150-3200 Å) studies of bright cosmic sources. However, achieving the superb wavelength precision inherent in its UV echelle channels is hampered by subtle camera distortions that are not fully compensated for by the CALSTIS pipe…