Results 51 to 60 of about 83,683 (249)

Parallaxes of L and T dwarfs [PDF]

Proceedings of the International Astronomical Union, 2004
We discuss a new program to measure the parallaxes of a number of L and T dwarfs, objects that bridge the gap between M dwarfs and planets. This pilot project tests the feasibility of using large telescopes with infrared detectors to determine parallaxes at the level of milli-arcseconds (mas). First results show that we are able to achieve the required
R. L. Smart, C. A. L. Bailer-Jones, H. R. A. Jones   +2 more
openaire   +1 more source

Unraveling the Molecular Mechanisms of Glioma Recurrence: A Study Integrating Single‐Cell and Spatial Transcriptomics

Annals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective Glioma recurrence severely impacts patient prognosis, with current treatments showing limited efficacy. Traditional methods struggle to analyze recurrence mechanisms due to challenges in assessing tumor heterogeneity, spatial dynamics, and gene networks.
Lei Qiu, Yinjiao Fei, Jiaxuan Ding, Kexin Shi, Jinyan Luo, Yuchen Zhu, Xingjian Sun, Gefei Jiang, Yuandong Cao, Weilin Xu, Shu Zhou   +10 more
wiley   +1 more source

Gray Spectral Variability in Three Brown Dwarfs Observed by HST/WFC3 Time-series Observations

The Astrophysical Journal
The L/T transition is a critical evolutionary stage for brown dwarfs and self-luminous giant planets. L/T transition brown dwarfs are more likely to be spectroscopically variable, and their high-amplitude variability probes distributions in their clouds ...
Madalyn F. Chapleski, Yifan Zhou
doaj   +1 more source

Disk or Companion: Characterizing Excess Infrared Flux in Seven White Dwarf Systems with Near-infrared Spectroscopy

The Astronomical Journal, 2023
Excess infrared flux from white dwarf stars is likely to arise from a dusty debris disk or a cool companion. In this work, we present near-infrared spectroscopic observations with Keck/MOSFIRE, Gemini/GNIRS, and Gemini/Flamingos-2 of seven white dwarfs ...
Dylan Owens, Siyi Xu, Elena Manjavacas, S. K. Leggett, S. L. Casewell, Erik Dennihy, Patrick Dufour, Beth L. Klein, Sherry Yeh, B. Zuckerman   +9 more
doaj   +1 more source

Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs

, 2008
We present results from a high-resolution spectroscopic survey of 45 L dwarfs, which includes both very low-mass stars and brown dwarfs. Our spectra allow us to derive a significant number of new rotational velocities, and discover a slowly rotating (in ...
Basri, Gibor, Reiners, Ansgar
core   +1 more source

Immune Checkpoint Inhibitor–Related Myositis and Associated Triad Overlap Syndrome

Arthritis Care &Research, EarlyView.
Objective Immune checkpoint inhibitor (ICI) myositis is a rare but a highly morbid condition, particularly with the ICI myositis triad syndrome of myositis, myocarditis, and myasthenia gravis. We report the clinical characteristics of ICI myositis and all‐cause mortality in these patients.
Selene Rubino, Grant W. Cannon, Brian C. Sauer, Jorge Rojas, Gregory J. Stoddard, Gary A. Kunkel, Jessica A. Walsh, Bryant R. England, Joshua F. Baker, Tawnie J. Braaten   +9 more
wiley   +1 more source

A Possible Correlation between Metallicity and Near-IR Color for Late-M and L Dwarfs

The Astrophysical Journal
We examine the relationship between metallicity and J − K color for 64 benchmark late-M and L dwarfs, all of which are wide companions to higher-mass stars, and six of which are new discoveries.
Ruihan Zhang, Michael C. Liu, Zhoujian Zhang   +2 more
doaj   +1 more source

Resolved Spectroscopy of M Dwarf/L Dwarf Binaries. II. 2MASS J17072343-0558249AB

The Astronomical Journal, 2006
We present IRTF SpeX observations of the M/L binary system 2MASS J17072343-0558249. SpeX imaging resolves the system into a 1"01+/-0.17 visual binary in which both components have red near infrared colors. Resolved low-resolution (R~150) 0.8-2.5 micron spectroscopy reveals strong H2O, CO and FeH bands and alkali lines in the spectra of both components,
McElwain, Michael W., Burgasser, Adam J.
openaire   +2 more sources

Al–Cu Composite Casting of Laser‐Deoxidized Copper: Bonding, Interfacial Chemistry, and Thermal Conductivity

Advanced Engineering Materials, EarlyView.
This study investigates laser‐based oxide removal of Cu inserts in oxygen‐free conditions and examines long‐term oxidation kinetics and surface chemistry under different atmospheres via X‐ray photoelectron spectroscopy. Al–Cu compound casting with differently oxidized surfaces is performed, and intermetallic phase formation, morphology, and thermal ...
Timon Steinhoff, Finn‐Lennard Janthur, Sascha Zimmermann, Sarah Seffer, Jörg Hermsdorf, René Gustus, Ludger Overmeyer, Wolfgang Maus‐Friedrichs, Hans Jürgen Maier, Christian Klose   +9 more
wiley   +1 more source

Searching for Exosatellites Orbiting L and T Dwarfs: Connecting Planet Formation to Moon Formation and Finding New Temperate Worlds [PDF]

, 2019
L-type and T-type dwarfs span the boundaries between main-sequence stars, brown dwarfs, and planetary-mass objects. For these reasons, L and T dwarfs are the perfect laboratories for exploring the relationship between planet formation and moon formation,
Burgasser, Adam, Faherty, Jacqueline, Gagliuffi, Daniella Bardalez, Muirhead, Philip S., Radigan, Jacqueline, Skinner, Julie N., Stephens, Denise, Tamburo, Patrick, Theissen, Christopher, Triaud, Amaury   +9 more
core   +2 more sources