Search Publications
Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument
Juneau, S.; Moustakas, J.; Myers, Adam D. +267 more
The Dark Energy Spectroscopic Instrument (DESI) embarked on an ambitious 5 yr survey in 2021 May to explore the nature of dark energy with spectroscopic measurements of 40 million galaxies and quasars. DESI will determine precise redshifts and employ the baryon acoustic oscillation method to measure distances from the nearby universe to beyond red…
Characterizing the Fast Radio Burst Host Galaxy Population and its Connection to Transients in the Local and Extragalactic Universe
Ryder, Stuart D.; Tejos, Nicolas; Day, Cherie K. +23 more
We present the localization and host galaxies of one repeating and two apparently nonrepeating fast radio bursts (FRBs). FRB 20180301A was detected and localized with the Karl G. Jansky Very Large Array to a star-forming galaxy at z = 0.3304. FRB20191228A and FRB20200906A were detected and localized by the Australian Square Kilometre Array Pathfin…
The California-Kepler Survey. X. The Radius Gap as a Function of Stellar Mass, Metallicity, and Age
Owen, James E.; Howard, Andrew W.; Petigura, Erik A. +10 more
In 2017, the California-Kepler Survey (CKS) published its first data release (DR1) of high-resolution optical spectra of 1305 planet hosts. Refined CKS planet radii revealed that small planets are bifurcated into two distinct populations, super-Earths (smaller than 1.5 R ⊕) and sub-Neptunes (between 2.0 and 4.0 R ⊕), with few…
TESS Hunt for Young and Maturing Exoplanets (THYME). VI. An 11 Myr Giant Planet Transiting a Very-low-mass Star in Lower Centaurus Crux
Owen, James E.; Vanderburg, Andrew; Lester, Kathryn V. +48 more
Mature super-Earths and sub-Neptunes are predicted to be ≃ Jovian radius when younger than 10 Myr. Thus, we expect to find 5-15 R ⊕ planets around young stars even if their older counterparts harbor none. We report the discovery and validation of TOI 1227b, a 0.85 ± 0.05 R J (9.5 R ⊕) planet transiting a very-low-m…
Flares, Rotation, and Planets of the AU Mic System from TESS Observations
Barclay, Thomas; Latham, David W.; Wittenmyer, Robert A. +20 more
AU Mic is a young (~24 Myr), pre-main-sequence M dwarf star that was observed in the first month of science observations of the Transiting Exoplanet Survey Satellite (TESS) and reobserved 2 years later. This target has photometric variability from a variety of sources that is readily apparent in the TESS light curves; spots induce modulation in th…
Extremely Low Mass Ratio Contact Binaries. I. The First Photometric and Spectroscopic Investigations of Ten Systems
Li, Kai; Gao, Xing; Chen, Xu +4 more
The photometric and spectroscopic investigations of ten contact binaries were presented for the first time. It is discovered that the mass ratios of all the ten targets are smaller than 0.15, they are extremely low mass ratio contact binaries. Seven of them are deep contact binaries, two are medium contact binaries, while only one is a shallow con…
Classifying Be Star Variability With TESS. I. The Southern Ecliptic
Labadie-Bartz, Jonathan; Carciofi, Alex C.; Henrique de Amorim, Tajan +4 more
TESS photometry is analyzed for 430 classical Be stars observed in the first year of the mission. The often complex and diverse variability of each object in this sample is classified to obtain an understanding of the behavior of this class as a population. Ninety-seven percent of the systems are variable above the noise level, with timescales spa…
A 20 Second Cadence View of Solar-type Stars and Their Planets with TESS: Asteroseismology of Solar Analogs and a Recharacterization of π Men c
Barclay, Thomas; Chaplin, William J.; Hermes, J. J. +50 more
We present an analysis of the first 20 second cadence light curves obtained by the TESS space telescope during its extended mission. We find improved precision of 20 second data compared to 2 minute data for bright stars when binned to the same cadence (≈10%-25% better for T ≲ 8 mag, reaching equal precision at T ≈ 13 mag), consistent with pre-fli…
Scanning Disk Rings and Winds in CO at 0.01-10 au: A High-resolution M-band Spectroscopy Survey with IRTF-iSHELL
Banzatti, Andrea; Bosman, Arthur D.; Pontoppidan, Klaus M. +11 more
We present an overview and first results from a M-band spectroscopic survey of planet-forming disks performed with iSHELL on the Infrared Telescope Facility, using two slits that provide resolving power R ≈ 60,000-92,000 (5-3.3 km s-1). iSHELL provides a nearly complete coverage at 4.52-5.24 µm in one shot, covering >50 lines f…
The Stellar Halo of the Galaxy is Tilted and Doubly Broken
Conroy, Charlie; Ting, Yuan-Sen; Johnson, Benjamin D. +7 more
Modern Galactic surveys have revealed an ancient merger that dominates the stellar halo of our galaxy (Gaia-Sausage-Enceladus, GSE). Using chemical abundances and kinematics from the H3 Survey, we identify 5559 halo stars from this merger in the radial range r Gal = 6-60kpc. We forward model the full selection function of H3 to infer th…