Results 21 to 30 of about 114 (114)

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

Astronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin, R. Gerasimov, A. Calamida, M. Libralato, M. Scalco, D. Nardiello, M. Griggio, D. Apai, J. Anderson, A. Bellini, A. Burgasser   +10 more
wiley   +1 more source

JWST Imaging of the Closest Globular Clusters—V. The White Dwarfs Cooling Sequence of M4

Astronomische Nachrichten, Volume 346, Issue 2, February 2025.
ABSTRACT We combine infrared (IR) observations collected by the James Webb Space Telescope with optical deep images by the Hubble Space Telescope taken ~20 years earlier to compute proper‐motion membership for the globular cluster (GC) M4 (NGC 6121) along its entire white dwarf (WD) cooling sequence (CS).
Luigi R. Bedin, Mattia Libralato, Maurizio Salaris, Domenico Nardiello, Michele Scalco, Massimo Griggio, Jay Anderson, Pierre Bergeron, Andrea Bellini, Roman Gerasimov, Adam J. Burgasser, Daniel Apai   +11 more
wiley   +1 more source

Low-mass Stellar and Substellar Candidate Companions around Massive Stars in Sco OB1 and M17

The Astronomical Journal
Massive stars are recognized for their high degree of multiplicity, yet the mass ratio regime below 0.1 remains insufficiently explored. It is therefore unknown whether extremely low-mass (possibly substellar) companions can form and survive in the ...
Tinne Pauwels, Maddalena Reggiani, Hugues Sana, Laurent Mahy   +3 more
doaj   +1 more source

Geodynamics of Super‐Earth GJ 486b

Journal of Geophysical Research: Planets, Volume 129, Issue 10, October 2024.
Abstract Many super‐Earths are on very short orbits around their host star and, therefore, more likely to be tidally locked. Because this locking can lead to a strong contrast between the dayside and nightside surface temperatures, these super‐Earths could exhibit mantle convection patterns and tectonics that could differ significantly from those ...
Tobias G. Meier, Dan J. Bower, Tim Lichtenberg, Mark Hammond, Paul J. Tackley, Raymond T. Pierrehumbert, José A. Caballero, Shang‐Min Tsai, Megan Weiner Mansfield, Nicola Tosi, Philipp Baumeister   +10 more
wiley   +1 more source

Predicting the Detection Yields of Giant Planets and Brown Dwarfs with CSST Astrometry

The Astronomical Journal
Chinese Space Station Telescope (CSST), which will begin its scientific operations around 2027, is going to survey the sky area of the median-to-high Galactic latitude and median-to-high ecliptic latitude.
Yifan Xuan, Fabo Feng, Zhensen Fu, Shilong Liao, Zhaoxiang Qi, Yang Chen   +5 more
doaj   +1 more source

A Wolf 359 in Sheep's Clothing: Hunting for Substellar Companions in the Fifth-closest System Using Combined High-contrast Imaging and Radial Velocity Analysis

The Astronomical Journal, 2023
Wolf 359 (CN Leo, GJ 406, Gaia DR3 3864972938605115520) is a low-mass star in the fifth-closest neighboring system (2.41 pc). Because of its relative youth and proximity, Wolf 359 offers a unique opportunity to study substellar companions around M stars ...
Rachel Bowens-Rubin, Joseph M. Akana Murphy, Philip M. Hinz, Mary Anne Limbach, Andreas Seifahrt, Rocio Kiman, Maïssa Salama, Sagnick Mukherjee, Madison Brady, Aarynn L. Carter, Rebecca Jensen-Clem, Maaike A. M. van Kooten, Howard Isaacson, Molly Kosiarek, Jacob L. Bean, David Kasper, Rafael Luque, Gudmundur Stefánsson, Julian Stürmer   +18 more
doaj   +1 more source

JWST imaging of the closest globular clusters—I. Possible infrared excess among white dwarfs in NGC 6397

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire white dwarf (WD) cooling sequence (CS). The data allows us to probe fundamental astrophysical WD properties and to search for evidence in their colors for (or against ...
L. R. Bedin, D. Nardiello, M. Salaris, M. Libralato, P. Bergeron, A. J. Burgasser, D. Apai, M. Griggio, M. Scalco, J. Anderson, R. Gerasimov, A. Bellini   +11 more
wiley   +1 more source

Hipparcos, Gaia, and Radial Velocities Reveal that the Radio-emitting F Star HD 220242 Has an M Dwarf Companion, a Likely Source of the Radio Emission

The Astronomical Journal
The detection of circularly polarized, low-frequency radio emission offers the tantalizing possibility of observing interactions between stars and their possible substellar companions, as well as direct emission from exoplanets.
Megan Delamer, Guđmundur Stefánsson, Suvrath Mahadevan, Caleb I. Cañas, Harish K. Vedantham, Arvind F. Gupta, Joseph R. Callingham, Juan Bautista Climent Oliver, William Cochran, Rachel B. Fernandes, Evan Fitzmaurice, Jose Carlos Guirado, Michael Hartmann, Artie P. Hatzes, Elise Koo, Jessica E. Libby-Roberts, Joe P. Ninan, Miguel Pérez-Torres, Paul Robertson, Arpita Roy, Christian Schwab   +20 more
doaj   +1 more source

The deep eclipses of RW Aur revisited by long‐term photometric and spectroscopic monitoring

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract RW Aurigae is a young stellar system containing a classical T Tauri star as the primary component. It shows deep, irregular dimmings, first detected in 2010. At the University Observatory Jena, we carried out optical follow‐up observations. We performed multiband (BVRI) photometry of the system with the Cassegrain‐Teleskop‐Kamera II and the ...
Oliver Lux, Markus Mugrauer, Richard Bischoff   +2 more
wiley   +1 more source

Exomoon Phase Curves: Toroidal Exosphere Simulations of Exo‐Ios Orbiting 8 Exoplanets in Alkali Spectroscopy

Journal of Geophysical Research: Planets, Volume 129, Issue 3, March 2024.
Abstract Toroidal atmospheres and exospheres characterized at exoplanets may be fueled by volcanically active exomoons, often referred to as exo‐Ios. We study the neutral outgassing and volatile evolution of a close‐orbiting, evaporating satellite at eight candidate exoplanet‐exomoon systems WASP‐49,‐96,‐69,‐17 b, XO‐2N b, HAT‐P‐1 b, HD‐189733 b, and ...
M. Meyer zu Westram, A. V. Oza, A. Galli
wiley   +1 more source