Results 41 to 50 of about 115,605 (291)

The Evolution of Stellar X-Ray Activity and Angular Momentum as Seen by eROSITA, TESS, and Gaia

open access: yesThe Astrophysical Journal Letters
We have assembled a sample of ∼8200 stars with spectral types F5V–M5V, all having directly measured X-ray luminosities from eROSITA and rotation periods from TESS and having empirically estimated ages via their membership in stellar clusters and groups ...
Keivan G. Stassun, Marina Kounkel
doaj   +1 more source

Learning about the latitudinal distribution of starspots through the periodogram analysis of photometric data

open access: yesEPJ Web of Conferences, 2017
Starspots are cooler and darker than the stellar surface. Therefore, the emitted flux of a star changes when spots are visible on its surface. The presence of spots together with the stellar rotation leads to a periodic modulation on the light curve.
Santos Ângela R. G.   +4 more
doaj   +1 more source

Structural biology of ferritin nanocages

open access: yesFEBS Letters, EarlyView.
Ferritin is a conserved iron‐storage protein that sequesters iron as a ferric mineral core within a nanocage, protecting cells from oxidative damage and maintaining iron homeostasis. This review discusses ferritin biology, structure, and function, and highlights recent cryo‐EM studies revealing mechanisms of ferritinophagy, cellular iron uptake, and ...
Eloise Mastrangelo, Flavio Di Pisa
wiley   +1 more source

A High Stellar Obliquity in the WASP-7 Exoplanetary System [PDF]

open access: yes, 2011
We measure a tilt of 86+-6 deg between the sky projections of the rotation axis of the WASP-7 star, and the orbital axis of its close-in giant planet. This measurement is based on observations of the Rossiter-McLaughlin (RM) effect with the Planet Finder
Albrecht   +28 more
core   +3 more sources

On Stellar Rotation.

open access: yesThe Astrophysical Journal, 1942
Not ...
openaire   +1 more source

Structural insights into an engineered feruloyl esterase with improved MHET degrading properties

open access: yesFEBS Letters, EarlyView.
A feruloyl esterase was engineered to mimic key features of MHETase, enhancing the degradation of PET oligomers. Structural and computational analysis reveal how a point mutation stabilizes the active site and reshapes the binding cleft, expading substrate scope.
Panagiota Karampa   +5 more
wiley   +1 more source

Asteroseismology and Spectropolarimetry of the Exoplanet Host Star λ Serpentis

open access: yesThe Astronomical Journal, 2023
The bright star λ Ser hosts a hot Neptune with a minimum mass of 13.6 M _⊕ and a 15.5 day orbit. It also appears to be a solar analog, with a mean rotation period of 25.8 days and surface differential rotation very similar to the Sun.
Travis S. Metcalfe   +33 more
doaj   +1 more source

Meridional flow and differential rotation by gravity darkening in fast rotating solar-type stars [PDF]

open access: yes, 2001
An explanation is presented for the rather strong total surface differential rotation of the observed very young solar-type stars like AB Dor and PZ Tel.
Dikpati   +7 more
core   +2 more sources

A methionine‐lined active site governs carbocation stabilization and product specificity in a bacterial terpene synthase

open access: yesFEBS Letters, EarlyView.
This study reveals a unique active site enriched in methionine residues and demonstrates that these residues play a critical role by stabilizing carbocation intermediates through novel sulfur–cation interactions. Structure‐guided mutagenesis further revealed variants with significantly altered product profiles, enhancing pseudopterosin formation. These
Marion Ringel   +13 more
wiley   +1 more source

Meta-analysis of Photometric and Asteroseismic Measurements of Stellar Rotation Periods: The Lomb–Scargle Periodogram, Autocorrelation Function, and Wavelet and Rotational Splitting Analysis for 92 Kepler Asteroseismic Targets

open access: yesThe Astrophysical Journal, 2022
We perform intensity variability analyses (photometric analyses: the Lomb–Scargle periodogram, autocorrelation, and wavelet) and asteroseismic analysis of 92 Kepler solar-like main-sequence stars to understand the reliability of the measured stellar ...
Yuting Lu   +3 more
doaj   +1 more source

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