Results 61 to 70 of about 23,116,162 (197)
Magnetic fields in M dwarf stars from high-resolution infrared spectra
, 2009 Magnetic fields play a central role in the atmospheric properties and variability of active M dwarfs. Information on the strength and structure of magnetic fields in these objects is vital for understanding dynamo mechanisms and magnetically-driven ...
Kochukhov, Oleg, +12 more
core +1 more source
Stellar Cycle and Evolution of Polar Spots in an M+WD Binary
The Astrophysical JournalStellar activity cycles reveal continuous relaxation and induction of magnetic fields. The activity cycle is typically traced through the observation of cyclic variations in total brightness or Ca H&K emission flux of stars, as well as cyclic variations ...
Xinlin Zhao +7 more
doaj +1 more source
No Evidence for More Earth-sized Planets in the Habitable Zone of Kepler's M versus FGK Stars
The Astronomical Journal, 2023 Reliable detections of Earth-sized planets in the habitable zone remain elusive in the Kepler sample, even for M dwarfs. The Kepler sample was once thought to contain a considerable number of M-dwarf stars ( T _eff < 4000 K), which hosted enough Earth ...
Galen J. Bergsten +5 more
doaj +1 more source
The Astrophysical JournalInterpretation of data from faint dwarf galaxies is made challenging by observations limited to only the brightest stars. We present a major improvement to tackle this challenge by undertaking zoomed cosmological simulations that resolve the evolution of
Eric P. Andersson +6 more
doaj +1 more source
CARBON-TO-OXYGEN RATIOS IN M DWARFS AND SOLAR-TYPE STARS [PDF]
The Astrophysical Journal, 2016 ABSTRACT It has been suggested that high C/O ratios (>0.8) in circumstellar disks lead to the formation of carbon-dominated planets. Based on the expectation that elemental abundances in the stellar photospheres give the initial abundances in the circumstellar disks, the frequency distributions of C/O ratios of solar-type stars have ...
Tadashi Nakajima, Satoko Sorahana
openaire +2 more sources
Precise Mass, Orbital Motion, and Stellar Properties of the M-dwarf Binary LP 349−25AB
The Astrophysical JournalLP 349−25 is a well-studied close stellar binary system comprised of two late M dwarf stars, where both stars are close to the limit between star and brown dwarf. This system was previously identified as a source of gigahertz radio emission.
Salvador Curiel +3 more
doaj +1 more source
Barnard's Star and the M Dwarf Temperature Scale
The Astronomical Journal, 2004 The recently measured angular diameter of Barnard's star, together with its large and precise parallax, and a spectral energy distribution that extends from the near-ultraviolet to almost 12 μm establish some of the star's fundamental properties—we find a bolometric luminosity L = (3.46 ± 0.17) × 10-3 L⊙, radius R = 0.200 ± 0.008 R⊙, and effective ...
P. C. Dawson, M. M. De Robertis
openaire +1 more source
Reconciliation of M Dwarf and FGK Stellar Abundances with Galactic Chemical Evolution
The Astrophysical JournalPrevious studies report apparent chemical abundance discrepancies between M dwarfs and FGK stars in the solar neighborhood, raising questions about the origin of these differences. Using a statistical pipeline, we revisit whether M dwarf abundance ratios
T. C. L. Trueman +5 more
doaj +1 more source
In the Quest for Pulsation in Main-sequence M Dwarf Stars from TESS Observations
The Astrophysical JournalWe report the results of an extensive survey in the quest for pulsation signatures in main-sequence M dwarf stars, based on observations acquired by the TESS space mission.
R. G. S. B. De Amorim +5 more
doaj +1 more source
The Astronomical JournalMetal-poor M subdwarfs are among the oldest stellar populations and carry valuable information about the chemical enrichment history of the Milky Way. The measurements of chemical abundances of these stars therefore provide essential insights into the ...
Neda Hejazi +5 more
doaj +1 more source