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Interstellar Polarization Survey. III. Relation between Optical Polarization and Reddening in the General Interstellar Medium
Magalhães, A. M.; Kawabata, Koji S.; Rodrigues, C. V. +4 more
Optical starlight can be partially polarized while propagating through the dusty, magnetized interstellar medium (ISM). The polarization efficiency describes the polarization intensity fraction per reddening unit, P V /E(B - V), related to the interstellar dust grains and magnetic field properties. The maximum value observed, [P …
The Unusual M-dwarf Warm Jupiter TOI-1899 b: Refinement of Orbital and Planetary Parameters
Cochran, William D.; Mahadevan, Suvrath; Wisniewski, John +31 more
TOI-1899 b is a rare exoplanet, a temperate warm Jupiter orbiting an M dwarf, first discovered by Cañas et al. (2020) from a TESS single-transit event. Using new radial velocities (RVs) from the precision RV spectrographs HPF and NEID, along with additional TESS photometry and ground-based transit follow-up, we are able to derive a much more preci…
Dynamical Mass of the Young Brown Dwarf Companion PZ Tel B
Bowler, Brendan P.; Franson, Kyle
Dynamical masses of giant planets and brown dwarfs are critical tools for empirically validating substellar evolutionary models and their underlying assumptions. We present a measurement of the dynamical mass and an updated orbit of PZ Tel B, a young brown dwarf companion orbiting a late-G member of the β Pic moving group. PZ Tel A exhibits an ast…
Lensing in the Blue. II. Estimating the Sensitivity of Stratospheric Balloons to Weak Gravitational Lensing
Jauzac, Mathilde; Benton, Steven J.; Clark, Paul +23 more
The Superpressure Balloon-borne Imaging Telescope (SUPERBIT) is a diffraction-limited, wide-field, 0.5 m, near-infrared to near-ultraviolet observatory designed to exploit the stratosphere's space-like conditions. SUPERBIT's 2023 science flight will deliver deep, blue imaging of galaxy clusters for gravitational lensing analysis. In preparation, w…
Iron-rich Metal-poor Stars and the Astrophysics of Thermonuclear Events Observationally Classified as Type Ia Supernovae. I. Establishing the Connection
Casey, Andrew R.; Reggiani, Henrique; Schlaufman, Kevin C.
The progenitor systems and explosion mechanisms responsible for the thermonuclear events observationally classified as Type Ia supernovae are uncertain and difficult to uniquely constrain using traditional observations of Type Ia supernova host galaxies, progenitors, light curves, and remnants. For the subset of thermonuclear events that are proli…
TESS Spots a Super-puff: The Remarkably Low Density of TOI-1420b
López-Morales, Mercedes; Bieryla, Allyson; Latham, David W. +51 more
We present the discovery of TOI-1420b, an exceptionally low-density (ρ = 0.08 ± 0.02 g cm-3) transiting planet in a P = 6.96 days orbit around a late G-dwarf star. Using transit observations from TESS, LCOGT, Observatoire Privé du Mont, Whitin, Wendelstein, OAUV, Ca l'Ou, and KeplerCam, along with radial velocity observations from HARPS…
Mind the Gap. I. Hα Activity of M Dwarfs Near the Partially/Fully Convective Boundary and a New Hα Emission Deficiency Zone on the Main Sequence
Henry, Todd J.; Paredes, Leonardo A.; Jao, Wei-Chun +4 more
Since identifying the gap in the H-R Diagram (HRD) marking the transition between partially and fully-convective interiors, a unique type of slowly pulsating M dwarf has been proposed. These unstable M dwarfs provide new laboratories in which to understand how changing interior structures can produce potentially observable activity at the surface.…
Hazy with a Chance of Star Spots: Constraining the Atmosphere of Young Planet K2-33b
Vanderburg, Andrew; Mann, Andrew W.; Irwin, Jonathan M. +10 more
Although all-sky surveys have led to the discovery of dozens of young planets, little is known about their atmospheres. Here, we present multiwavelength transit data for the super-Neptune sized exoplanet, K2-33b-the youngest (~10 Myr) transiting exoplanet to date. We combined photometric observations of K2-33 covering a total of 33 transits spanni…
Spectroscopic Orbits of Subsystems in Multiple Stars. X (Summary)
Tokovinin, Andrei
Results of a large program of spectroscopic monitoring of nearby solar-type stellar hierarchical systems using the CHIRON echelle spectrograph at the 1.5 m telescope are summarized. Ten papers of this series contain 102 spectroscopic orbits and substantially contribute to the knowledge of periods and eccentricties, providing input for the study of…
Kinematic-chemical Analysis and Time Tagging for the Diagonal Ridge Structure of the Galactic Outer Disk with LAMOST Red-giant Branch Stars
Yang, Peng; Wang, Hai-Feng; Tepper-García, Thor +2 more
We investigate the kinematic-chemical distribution of red-giant branch stars from the LAMOST survey crossed matched with Gaia DR2 proper motions, and present time tagging for the well-known ridge structures (diagonal distributions for V R in the R, V ϕ plane) in the range of Galactocentric distance R = 8 to 15 kpc. We det…