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…
Detection of Ongoing Mass Loss from HD 63433c, a Young Mini-Neptune
Henry, Gregory W.; Knutson, Heather A.; Dai, Fei +9 more
We detect Lyα absorption from the escaping atmosphere of HD 63433c, a R = 2.67R ⊕, P = 20.5 day mini-Neptune orbiting a young (440 Myr) solar analog in the Ursa Major Moving Group. Using Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph, we measure a transit depth of 11.1 ± 1.5% in the blue wing and 8 ± 3% in the red. Th…
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…
The Featureless HST/WFC3 Transmission Spectrum of the Rocky Exoplanet GJ 1132b: No Evidence for a Cloud-free Primordial Atmosphere and Constraints on Starspot Contamination
Désert, Jean-Michel; Rackham, Benjamin V.; Morley, Caroline V. +10 more
Orbiting an M dwarf 12 pc away, the transiting exoplanet GJ 1132b is a prime target for transmission spectroscopy. With a mass of 1.7 M ⊕ and radius of 1.1 R ⊕, GJ 1132b's bulk density indicates that this planet is rocky. Yet with an equilibrium temperature of 580 K, GJ 1132b may still retain some semblance of an atmosphere. …
Escaping Helium from TOI 560.01, a Young Mini-Neptune
Knutson, Heather A.; Dai, Fei; Zhang, Michael +2 more
We report helium absorption from the escaping atmosphere of TOI 560.01 (HD 73583b), an R = 2.8R ⊕, P = 6.4 day mini-Neptune orbiting a young (~600 Myr) K dwarf. Using Keck/NIRSPEC, we detect a signal with an average depth of 0.68% ± 0.08% in the line core. The absorption signal repeats during a partial transit obtained a month later, bu…
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…