Results 51 to 60 of about 42,007 (286)
Accretion shock stability on a dynamically heated YSO atmosphere with radiative transfer
EPJ Web of Conferences, 2014 Theory and simulations predict Quasi-Periodic Oscillations of shocks which develop in magnetically driven accretion funnels connecting the stellar disc to the photosphere of Young Stellar Objects (YSO).
de Sá Lionel +6 more
doaj +1 more source
A Robust Adaptive One‐Sample‐Ahead Preview Super‐Twisting Sliding Mode Controller
International Journal of Adaptive Control and Signal Processing, EarlyView.Block Diagram of the Robust Adaptive One‐Sample‐Ahead Preview Super‐Twisting Sliding Mode Controller. ABSTRACT This article introduces a discrete‐time robust adaptive one‐sample‐ahead preview super‐twisting sliding mode controller. A stability analysis of the controller by Lyapunov criteria is developed to demonstrate its robustness in handling both ...
Guilherme Vieira Hollweg +5 more
wiley +1 more source
Time-resolved p-mode Oscillations for Subgiant HD 142091 with NEID at WIYN
The Astrophysical JournalDetections of Earth-analog planets in radial velocity (RV) observations are limited by stellar astrophysical variability occurring on a variety of timescales. Current state-of-the-art methods to disentangle potential planet signals from intrinsic stellar
Jacob K. Luhn +24 more
doaj +1 more source
Oscillations in stellar atmospheres
The Astrophysical Journal, 1989 Atmospheric excitation and propagation of oscillations are analyzed for typical pulsating stars. The linear, plane-parallel approach for the pulsating atmosphere gives a local description of the phenomenon. From the local analysis of oscillations, the minimum frequencies are obtained for radially propagating waves.
A. Costa +2 more
openaire +1 more source
Multiplexed Interferometric Stellar Oscillation Spectrometry — MISOS [PDF]
Symposium - International Astronomical Union, 1988 Interferometric spectrometry techniques for measuring stellar oscillations have been developed at Imperial College, resulting in two separate interferometers, the Michelson and the Fabry-Perot based instruments. They have both been used on large telescopes; the Michelson instrument to search for oscillations in solar-type stars and the Fabry-Perot ...
K.A.R.B. Pietraszewski +4 more
openaire +1 more source
Advanced Engineering Materials, EarlyView.Powder metal processing provides scalable advantages in nanoporous (np) metal development. Mechanical alloying is used to produce unique precursors for hybrid nanopore formation by oxide reduction and dealloying. As demonstrated in np Ag, this approach improves process efficiency while promoting smaller ligaments and larger pores, both of which are ...
Mark A. Atwater, Oliver A. Fowler
wiley +1 more source
Is macroturbulent broadening in OB Supergiants related to pulsations?
, 2010 The spectrum of O and B Supergiants is known to be affected by an important extra line-broadening (usually called macroturbulence) that adds to stellar rotation.
Aerts +31 more
core +1 more source
Advanced Engineering Materials, EarlyView.This study explores the lightweight potential of laser additive‐manufactured NiTi triply periodic minimal surface sheet lattices. It systematically investigates the effects of relative density and unit cell size on surface quality, deformation recovery, compression behavior, and energy absorption.
Haoming Mo +3 more
wiley +1 more source
TESS Asteroseismology of β Hydri: A Subgiant with a Born-again Dynamo
The Astrophysical JournalThe solar-type subgiant β Hyi has long been studied as an old analog of the Sun. Although the rotation period has never been measured directly, it was estimated to be near 27 days.
Travis S. Metcalfe +14 more
doaj +1 more source
The SAGA so far: reading the history of the Galaxy with asteroseismology
EPJ Web of Conferences, 2015 Asteroseismology has the capability of delivering stellar properties which would otherwise be inaccessible, such as radii, masses and thus ages of stars.
Casagrande Luca +5 more
doaj +1 more source