Results 41 to 50 of about 17,015 (215)

Speckle noise reduction techniques for high-dynamic range imaging [PDF]

open access: yes, 2007
High-dynamic range imaging from space in the visible, aiming in particular at the detection of terrestrial exoplanets, necessitates not only the use of a coronagraph, but also of adaptive optics to correct optical defects in real time.
Belikov   +23 more
core   +3 more sources

Lithium Niobate Quadratic Integrated Nonlinear Photonics: Enabling Ultra‐Wide Bandwidth and Ultrafast Photonic Engines

open access: yesNanophotonics, Volume 15, Issue 9, 13 May 2026.
This perspective surveys emerging quantum and classical photonic applications across operating wavelengths and timescales, highlighting persistent technological gaps in integrated light sources. We examine the unique advantages of quadratic nonlinear photonics on the thin‐film lithium niobate (TFLN) platform and discuss strategies for realizing ...
Meng Tian   +7 more
wiley   +1 more source

Impacting Atmospheres: How Late-stage Pollution Alters Exoplanet Composition

open access: yesThe Astrophysical Journal
The atmospheric composition of exoplanets is often considered as a probe of the planet’s formation conditions. How exactly the initial chemical memory may be altered from the birth to the final state of the planet, however, remains unknown.
Emilia Vlahos   +3 more
doaj   +1 more source

Evidence for Low-level Dynamical Excitation in Near-resonant Exoplanet Systems

open access: yesThe Astronomical Journal, 2023
The geometries of near-resonant planetary systems offer a relatively pristine window into the initial conditions of exoplanet systems. Given that near-resonant systems have likely experienced minimal dynamical disruptions, the spin–orbit orientations of ...
Malena Rice   +20 more
doaj   +1 more source

Effects of rotation and magnetic fields on the lithium abundance and asteroseismic properties of exoplanet-host stars

open access: yes, 2010
Aims: The effects of rotation and magnetic fields on the surface abundances of solar-type stars are studied in order to investigate whether the reported difference in lithium content of exoplanet-host stars can be related to their rotational history ...
A. Maeder   +30 more
core   +1 more source

Detecting the Signatures of Uranus and Neptune [PDF]

open access: yes, 2011
With more than 15 years since the the first radial velocity discovery of a planet orbiting a Sun-like star, the time baseline for radial velocity surveys is now extending out beyond the orbit of Jupiter analogs.
Bakos   +55 more
core   +1 more source

The Impact of the Sulfur Allotropes and Sulfur Hydrides on the Venus Cloud Chemistry

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 5, May 2026.
Abstract Venus is home to vivid sulfur chemistry, with SO2 ${\text{SO}}_{2}$ as the major sulfur gas species and a global cloud layer between 47 and 70 km composed of H2SO4 ${\mathrm{H}}_{2}{\text{SO}}_{4}$ and H2 ${\mathrm{H}}_{2}$O. The chemistry in the clouds has been extensively studied with 1D models, but none is able to reproduce the three orders
Maxence Lefèvre   +6 more
wiley   +1 more source

The Not-so Dramatic Effect of Advective Flows on Gas Accretion

open access: yesThe Astrophysical Journal
Super-Earths and mini-Neptunes are the most common types of exoplanets discovered, yet the physics of their formation are still debated. Standard core accretion models in gas-rich environments find that typical mini-Neptune mass planets would blow up ...
Vincent Savignac, Eve J. Lee
doaj   +1 more source

Impacts of Carbon Dioxide Deposition on Martian Near‐Surface Wave Activity

open access: yesGeophysical Research Letters, Volume 53, Issue 7, 16 April 2026.
Abstract A prominent feature of Mars' winter atmosphere is near‐surface baroclinic wave activity. These waves exert strong control on dust storm variability and contribute to transport of heat, momentum, and dust. Using a suite of Mars general circulation model simulations, we investigate an underexplored connection between near‐surface wave activity ...
Hung Kwan Fok   +2 more
wiley   +1 more source

Orbital Migration of Protoplanets in a Marginally Gravitationally Unstable Disk. II. Migration, Merging, and Ejection

open access: yesThe Astrophysical Journal, 2023
Protoplanets formed in a marginally gravitationally unstable (MGU) disk by either core accretion or disk instability will be subject to dynamical interactions with massive spiral arms, possibly resulting in inward or outward orbital migration, mergers ...
Alan P. Boss
doaj   +1 more source

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