Thermal generation of magnetic fields with radiation pressure in rotating stars

1969 ◽  
Vol 5 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Shoji Kato ◽  
Y. Nakagawa
Keyword(s):  
Magnetic Fields ◽  
Radiation Pressure ◽  
Rotating Stars ◽  
Thermal Generation

Generation of Magnetic Fields by Radiation Pressure from the First Stars

2010 ◽  
Author(s):  
Hajime Susa ◽  
Masashi Ando ◽  
Kentaro Doi ◽  
Daniel J. Whalen ◽  
Volker Bromm ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Radiation Pressure ◽  
First Stars

scholarly journals On the influence of magnetic fields in neutral planetary wakes

2016 ◽  
Vol 12 (S328) ◽  
pp. 192-197
Author(s):  
C. Villarreal D’Angelo ◽  
M. Schneiter ◽  
A. Esquivel
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Radiation Pressure ◽  
Stellar Wind ◽  
Magnetic Moments ◽  
Radiative Processes ◽  
Planetary Magnetic Fields ◽  
Stellar Magnetic Fields

AbstractWe present a 3D magnetohydrodynamic study of the effect that stellar and planetary magnetic fields have on the calculated Lyα absorption during the planetary transit, employing parameters that resemble the exoplanet HD209458b. We assume a dipolar magnetic field for both the star and the planet, and use the Parker solution to initialize the stellar wind. We also consider the radiative processes and the radiation pressure.We use the numerical MHD code Guacho to run several models varying the values of the planetary and stellar magnetic moments within the range reported in the literature.We found that the presence of magnetic fields influences the escaping neutral planetary material spreading the absorption Lyα line for large stellar magnetic fields.

scholarly journals Magnetic Fields in Rapidly Rotating Stars

1973 ◽  
Vol 162 (3) ◽  
pp. 289-293
Author(s):  
M. Maheswaran ◽  
H. A. B. M. de Silva
Keyword(s):  
Magnetic Fields ◽  
Rotating Stars ◽  
Rapidly Rotating Stars

scholarly journals Some travels in the land of nonlinear convection and magnetism

2019 ◽  
Vol 82 ◽  
pp. 273-294
Author(s):  
J. Toomre
Keyword(s):  
Magnetic Fields ◽  
Turbulent Convection ◽  
Rotating Stars ◽  
Dynamo Action ◽  
Penetrative Convection ◽  
Nonlinear Convection ◽  
Horizontal Structure ◽  
Solar Convection ◽  
Jean Paul ◽  
Anelastic Equations

Rotating stars with convection zones are the great builders of magnetism in our universe. Seeking to understand how turbulent convection actually operates, and so too the dynamo action that it can achieve, has advanced through distinctive stages in which Jean-Paul Zahn was often a central player, or joined by his former students. Some of the opening steps in dealing with the basic nonlinearity in such dynamics involved modal equations (with specified horizontal structure) to study convective amplitudes and heat transports achieved as solutions equilibrated by feeding back on the mean stratification. These dealt in turn with laboratory convection, with penetrative convection in Boussinesq settings, then with compressible penetration via anelastic equations in simple geometries, and finally with stellar penetrative convection in A-type stars that coupled two convection zones. Advances in computation power allowed 2-D fully compressible simulations, and then 3-D modeling including rotation, to revisit some of these convection and penetration settings within planar layers. With externally imposed magnetic fields threading the 2-D layers, magnetoconvection could then be studied to see how the flows concentrated the fields into complex sheets, or how new classes of traveling waves could result. The era of considering turbulent convection in rotating spherical shells had also arrived, using 3-D MHD codes such as ASH to evaluate how the solar differential rotation is achieved and maintained. Similarly the manner in which global magnetic fields could be built by dynamo action within the solar convection zone took center stage, finding that coherent wreaths of strong magnetism could be built, and also cycling solutions with field reversals. The coupling of convection and magnetism continues as a vibrant research subject. It is also clear that stars like the Sun do not give up their dynamical mysteries readily when highly turbulent systems are at play.

scholarly journals MHD Models of Planetary Nebulae: Review

2003 ◽  
Vol 209 ◽  
pp. 457-464 ◽  
Author(s):  
Guillermo García-Segura
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Ab Initio ◽  
Radiation Pressure ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Basic Question ◽  
Red Giants ◽  
Outer Envelope ◽  
Parent Star

When we discuss about MHD effects in planetary nebulae (PNe), there naturally arises a basic question: which magnetic field do we study? One possibility is the ISM magnetic field (e.g. Heiligman 1980), even more if we are concerned with moving PNe (e.g. Soker & Dgani 1997). The next possibility is the internal or stellar magnetic field (Gurzadian 1962). It is important to start this review by quoting Aller (1958): “It has been pointed out by Minkowski and others that the structural appearance of many planetary nebulae strongly suggest the presence of magnetic fields. It seems unlikely that such magnetic fields are produced ab initio in the nebular shell. Rather, they must have existed in the outer envelope of the parent star. Certain red giants stars with magnetic fields may evolve in such a way that the expansion of the shell is largely governed by the presence of such a field. Magnetic effects may actually be more important than gas pressure differentials and radiation pressure in controlling the evolution of a planetary nebula”.

scholarly journals Rayleigh-Teilchen (a < 10-5 cm) im interplanetaren Raum?

1966 ◽  
Vol 21 (7) ◽  
pp. 1116-1122 ◽  
Author(s):  
Hans Elsässer ◽  
Thomas Schmidt
Keyword(s):  
Solar Wind ◽  
Magnetic Fields ◽  
Radiation Pressure ◽  
Interplanetary Space ◽  
Submicron Particles ◽  
Spatial Density ◽  
Zodiacal Light

The question if submicron particles could be present in interplanetary space is discussed in some detail. On the assumption that the polarization of the zodiacal light is due to scattering of sunlight by submicron particles their spatial density is derived (chapter 2). The investigation of the forces exerted on those particles by the radiation pressure of sunlight and by interaction with the particles and magnetic fields of the solar wind shows that the „lifetime“ of submicron particles in interplanetary space is probably less than 103 years (chapter 1 and 3). Therefore it seems doubtful that they can exist in considerable numbers.

scholarly journals Equilibrium solutions of relativistic rotating stars with mixed poloidal and toroidal magnetic fields

2014 ◽  
Vol 90 (10) ◽  
Author(s):  
Kōji Uryū ◽  
Eric Gourgoulhon ◽  
Charalampos M. Markakis ◽  
Kotaro Fujisawa ◽  
Antonios Tsokaros ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Rotating Stars ◽  
Equilibrium Solutions

scholarly journals Magnetic Fields in Low-Mass Stars: An Overview of Observational Biases

2013 ◽  
Vol 9 (S302) ◽  
pp. 156-163 ◽  
Author(s):  
Ansgar Reiners
Keyword(s):  
Magnetic Fields ◽  
Zeeman Effect ◽  
Field Measurements ◽  
Rotating Stars ◽  
Magnetic Field Generation ◽  
Low Mass Stars ◽  
Important Indicator ◽  
Stellar Radius ◽  
Low Mass ◽  
Rapidly Rotating Stars

AbstractStellar magnetic dynamos are driven by rotation, rapidly rotating stars produce stronger magnetic fields than slowly rotating stars do. The Zeeman effect is the most important indicator of magnetic fields, but Zeeman broadening must be disentangled from other broadening mechanisms, mainly rotation. The relations between rotation and magnetic field generation, between Doppler and Zeeman line broadening, and between rotation, stellar radius, and angular momentum evolution introduce several observational biases that affect our picture of stellar magnetism. In this overview, a few of these relations are explicitly shown, and the currently known distribution of field measurements is presented.

Sign in / Sign up

Export Citation Format

Share Document