Results 21 to 30 of about 1,009 (181)

Confirmation of a Non‐Transiting Planet in the Habitable Zone of the Nearby M Dwarf L 98‐59

Astronomische Nachrichten, EarlyView.
ABSTRACT Only 40 exoplanetary systems with five or more planets are currently known. These systems are crucial for our understanding of planet formation and planet‐planet interaction. The M dwarf L 98‐59 has previously been found to show evidence of five planets, three of which are transiting.
Paul I. Schwarz, Stefan Dreizler, René Heller   +2 more
wiley   +1 more source

The HD 191939 Exoplanet System is Well Aligned and Flat

The Astronomical Journal
We report the sky-projected spin–orbit angle λ for HD 191939 b, the innermost planet in a six-planet system, using Keck/KPF to detect the Rossiter–McLaughlin (RM) effect.
Jack Lubin, Erik A. Petigura, Judah Van Zandt, Corey Beard, Fei Dai, Samuel Halverson, Rae Holcomb, Andrew W. Howard, Howard Isaacson, Jacob Luhn, Paul Robertson, Ryan A. Rubenzahl, Guđmundur Stefánsson, Joshua N. Winn, Max Brodheim, William Deich, Grant M. Hill, Steven R. Gibson, Bradford Holden, Aaron Householder, Russ R. Laher, Kyle Lanclos, Joel Payne, Arpita Roy, Roger Smith, Abby P. Shaum, Christian Schwab, Josh Walawender   +27 more
doaj   +1 more source

Commissioning an Inexpensive Off‐The‐Shelf Spectrograph for Radial‐Velocity Studies

Astronomische Nachrichten, EarlyView.
ABSTRACT We present a way to set up an inexpensive out of the shelf spectrograph at a local observatory. Stability and resolution of the spectrograph are high enough for radial velocity determination of binary stars or determination of stellar characteristics. Even some exoplanets might be detectable via the radial velocity method.
Lukas Stock, Andreas Schrimpf
wiley   +1 more source

Ponderings on the Possible Preponderance of Perpendicular Planets

The Astrophysical Journal Letters, 2023
Misalignments between planetary orbits and the equatorial planes of their host stars are clues about the formation and evolution of planetary systems. Earlier work found evidence for a peak near 90° in the distribution of stellar obliquities, based on ...
Jared C. Siegel, Joshua N. Winn, Simon H. Albrecht   +2 more
doaj   +1 more source

Altitude Profile and Isotopic Composition for N2 From Pioneer Venus Mass Spectra

Geophysical Research Letters, Volume 52, Issue 23, 16 December 2025.
Abstract We report the highest resolution altitude profile and isotopic composition for N2 at Venus, to date. These results were obtained through re‐analysis of data acquired by the Pioneer Venus Large Probe Neutral Mass Spectrometer (LNMS). The N2 is non‐uniformly mixed across the clouds and sub‐cloud atmosphere (∼59–15 km) yet uniformly mixed across ...
R. Mogul, S. S. Limaye, M. J. Way
wiley   +1 more source

The First Evidence of a Host Star Metallicity Cutoff in the Formation of Super-Earth Planets

The Astronomical Journal
Planet formation is expected to be severely limited in disks of low metallicity, owing to both the small solid mass reservoir and the low-opacity accelerating the disk gas dissipation.
Kiersten M. Boley, Jessie L. Christiansen, Jon Zink, Kevin Hardegree-Ullman, Eve J. Lee, Philip F. Hopkins, Ji Wang, Rachel B. Fernandes, Galen J. Bergsten, Sakhee Bhure   +9 more
doaj   +1 more source

The Power of a Name: Toward a Unified Approach to Naming Space Weather Events

Perspectives of Earth and Space Scientists, Volume 6, Issue 1, December 2025.
Abstract Our increasing reliance on technology vulnerable to space weather effects underscores the urgent need for effective public communication about these phenomena. While scientific research thrives on precise technical language, broader public engagement necessitates a more accessible and memorable approach.
Sophie Chabanski, Felix de Montety, Jean Lilensten, Stefaan Poedts, Luca Spogli   +4 more
wiley   +1 more source

Gravity-sensitive Spectral Indices in Ultracool Dwarfs: Investigating Correlations with Metallicity and Planet Occurrence Using SpeX and Fire Observations

The Astronomical Journal
We present a near-infrared spectroscopic analysis (0.9–2.4 μ m) of gravity indices for 56 ultracool dwarfs (M5.5–L0), including exoplanet hosts SPECULOOS-2, SPECULOOS-3, and LHS 3154.
Fatemeh Davoudi, Benjamin V. Rackham, Julien de Wit, Jan Toomlaid, Michaël Gillon, Amaury H. M. J. Triaud, Adam J. Burgasser, Christopher A. Theissen   +7 more
doaj   +1 more source

Community Voices on the Future of Radiation Belt Research: A Summary of the 2024 GEM Radiation Belt Focus Group Round‐Table Discussion

Earth and Space Science, Volume 12, Issue 12, December 2025.
Abstract Earth's radiation belts are the regions where highly energetic charged particles are trapped by Earth's magnetic field, posing significant risks to the satellites and other space‐based technologies. Understanding the dynamics of the radiation belts is critical not only for advancing fundamental plasma physics but also for predicting and ...
Hong Zhao, Lauren Blum, Aleksandr Ukhorskiy, Xiangrong Fu   +3 more
wiley   +1 more source

Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions

The Astronomical Journal, 2023
Directly imaging temperate rocky planets orbiting nearby, Sun-like stars with a 6 m class IR/O/UV space telescope, recently dubbed the Habitable Worlds Observatory, is a high-priority goal of the Astro2020 Decadal Survey.
Katherine Laliotis, Jennifer A. Burt, Eric E. Mamajek, Zhexing Li, Volker Perdelwitz, Jinglin Zhao, R. Paul Butler, Bradford Holden, Lee Rosenthal, B. J. Fulton, Fabo Feng, Stephen R. Kane, Jeremy Bailey, Brad Carter, Jeffrey D. Crane, Elise Furlan, Crystal L. Gnilka, Steve B. Howell, Gregory Laughlin, Stephen A. Shectman, Johanna K. Teske, C. G. Tinney, Steven S. Vogt, Sharon Xuesong Wang, Robert A. Wittenmyer   +24 more
doaj   +1 more source