Results 71 to 80 of about 10,538,954 (217)
Rotation effects in classical T Tauri stars [PDF]
Astronomy Letters, 2012 Surface temperature inhomogeneities in classical T Tauri stars (CTTS) induced by magnetic activity and mass accretion lead to rotational modulation of both photometric and spectroscopic parameters of these stars. Using the extended photometric catalogue by Grankin et al. (2007), we have derived the periods and amplitudes of the rotational modulation of
Artemenko, Svetlana A. +2 more
openaire +2 more sources
A Pre-main-sequence Binary Viewed Through Its Circumbinary Disk: A New Phase for KH 15D
The Astronomical JournalThe binary T Tauri system, KH 15D, is poised to provide unprecedented detail of gas and ices located between ∼3 and 5 au of its circumbinary disk over the next few years. We analyze for the first time a complete set of ground-based time-series photometry
Catrina M. Hamilton +18 more
doaj +1 more source
The Türkiye‐Qatar Partnership: From Ottoman Roots to Strategic Alliance
Middle East Policy, Volume 33, Issue 3, Autumn (Fall) 2026.Abstract As Qatar, a small country in a strategic location, faced a pressure campaign from Gulf states in 2017, Türkiye expanded its military presence and provided support that proved crucial to Doha's ability to overcome the crisis. This demonstrated Türkiye's new grand strategy, its capacity to project influence into the Gulf, and its status as a ...
Ismail Köse, Fatma Alghussein
wiley +1 more source
The Variability of the T Tauri Star DI Cephei [PDF]
International Astronomical Union Colloquium, 1983 Abstract:It is demonstrated that the light variations of DI Cephei can be explained as due to the combined effect of variable completely grey circumstellar extinction and variable continuous and line emission.
G. F. Gahm, P. P. Petrov
openaire +1 more source
ABYSS. III. Observing Accretion Activity in Young Stars Through Empirical Veiling Measurements
The Astronomical JournalStellar accretion plays an important role in the early stages of stellar evolution, particularly in Classical T Tauri Stars (CTTSs). Accretion of a CTTS can be related to different physical parameters such as effective temperature ( T _eff ), age ...
Serat Saad +7 more
doaj +1 more source
Rethinking Political Islam in Iran: Contestation, Authority, and Reform
Middle East Policy, Volume 33, Issue 3, Autumn (Fall) 2026.Abstract Political Islam in Iran is frequently portrayed in Western scholarship and policy discourse as a unified and rigid ideological system rooted in the 1979 Islamic Revolution. However, this article contends that it operates as a plural and internally contested field in which state‐directed, reformist‐clerical, and civic interpretations compete ...
Nagapushpa Devendra
wiley +1 more source
THE MAGNETIC FIELD IMPACT ON ACCRETION RATE IN A PROTOPLANETARY DISK
Odessa Astronomical Publications, 2012 Recent observations are the evidence of a large-scale magnetic field in discs around classical T Tauri stars. A model of the axisymmetric thin protoplanetary disk in a global magnetic field is considered.
M. M. Kuksa
doaj +1 more source
Noûs, Volume 60, Issue 3, Page 593-605, September 2026.ABSTRACT It is a truism of mathematics that differences between isomorphic number systems are irrelevant to arithmetic. This truism is deeply rooted in the modern axiomatic method and underlies most strands of arithmetical structuralism, the view that arithmetic is about some abstract number structure.
Balthasar Grabmayr
wiley +1 more source
Post–T Tauri Stars: A False Problem [PDF]
The Astrophysical Journal, 1997 6 pages (LaTeX), no Figures to be published in The Astrophysical Journal ...
Palla, F., Galli, D.
openaire +2 more sources
Variable X-Ray Emission of the Planet Hosting T Tauri Star CI Tau
The Astronomical JournalWe report results of Chandra X-ray observations of CI Tau, a young magnetically active classical T Tauri star for which previous studies have reported periodic variability attributed to a massive planet in a short-period orbit.
Stephen L. Skinner, Manuel Güdel
doaj +1 more source