The Sun and Cool Stars: activity, magnetism, dynamos: Proceedings of Colloquium No. 130 of the International Astronomical Union Held in Helsinki, Finland, 17–20 July 1990

The confrontation of mean-field theories with numerical simulations....Pages 1-14
On numerical studies of solar/stellar convection....Pages 15-26
Turbulent Convection: A New Model....Pages 27-32
Large scale convection in stars : Towards a model for the action of coherent structures....Pages 33-36
Magnetoconvection patterns in rotating convection zones....Pages 37-56
Stellar convection as a low Prandtl number flow....Pages 57-61
Convective overshoot as a source of helicity....Pages 62-66
Topological pumping in the lower overshoot layer....Pages 67-70
Diffusion of particles, heat and magnetic fields in compressible turbulent media....Pages 71-74
The spatial structure of homogeneous turbulence at high Reynolds number....Pages 75-79
Compressible MHD in spherical geometry....Pages 80-85
The role of overshoot in solar activity: A direct simulation of the dynamo....Pages 86-88
Vector potential magnetic null points....Pages 89-91
Magnetic tubes in overshooting compressible convection....Pages 92-94
Convective cores in stellar models....Pages 95-97
Rotational effects on Reynolds stresses in the solar convection zone....Pages 98-100
Stable and unstable solutions of the nonlinear dynamo problem....Pages 101-111
Nonlinear nonaxisymmetric dynamos for active stars....Pages 112-116
Waves of Solar Activity....Pages 117-128
Non-steady global magnetic fields in kinematic theory....Pages 129-134
Asymptotic methods in the nonlinear mean-field dynamo....Pages 135-139
Fractal flux tubes of the solar magnetic field....Pages 140-146
 αΛ -dynamos....Pages 147-150
Fossil magnetic fields and activity of young stars....Pages 151-153
The sun's internal differential rotation from helioseismology....Pages 155-171
 Λ -effect, meridional flow and the differential solar rotation....Pages 172-177
Differential rotation as an axisymmetric resonant mode of convection....Pages 178-181
The solar internal rotation and its implications....Pages 182-186
The toroidal magnetic field inside the Sun....Pages 187-189
The transfer of large-scale magnetic field by radial inhomogeneity of the material density in the rotating convection zone....Pages 190-192
Diagnostics of the solar dynamo using the observed pattern of surface magnetic fields....Pages 193-212
The large-scale magnetic field in the global solar cycle: observational aspects....Pages 213-217
Evolution of large and small scale magnetic fields in the sun....Pages 218-222
The solar dynamo....Pages 223-233
A topological model of the solar magnetic field reversals....Pages 234-236
Solar internal rotation, the boundary layer dynamo and latitude distribution of activity belts....Pages 237-240
Solar rotation over solar cycle 21....Pages 241-245
Sun-as-a-star: Its convective signature and the activity cycle....Pages 246-251
The hel ⋋10830 Å line as an indicator of the chromospheric and coronal activity of the sun....Pages 252-265
The rotational modulation of ca II K in the sun....Pages 266-267
The prolonged minima and maxima of solar activity....Pages 268-270
The longer term evolution of magnetic field and mass flow in a decaying active region....Pages 271-274
The main component analysis of the longitudinal distribution of solar activity....Pages 275-276
Fe I line asymmetries and shifts caused by pressure broadening....Pages 277-278
Rotation of large scale patterns on the solar surface as determined from filament and millimeter data....Pages 279-281
Large scale patterns on the solar surface indicated by microwave observations....Pages 282-284
The solar corona over the recent saros....Pages 285-287
The history of activity of the Sun and its rotational period on the ZAMS....Pages 288-293
The differential rotation and evolution of spots on UX Arietis from a sequence of Doppler images....Pages 295-308
The art of surface imaging....Pages 309-320
Surface imaging of El Eri....Pages 321-325
Towards magnetic images of rapidly rotating late-type stars....Pages 326-329
Chromospheric surface structures on El Eridani and HD 199178....Pages 330-332
Activity, colour anomalies and temperature determination in solar-type stars....Pages 333-335
Dynamo action in evolved stars....Pages 336-341
The boundary between the magnetic fields of ap stars and the fields of solar-type stars....Pages 342-346
Doppler mapping of CP-star surfaces with weak and strong magnetic fields....Pages 347-349
Temperature variations on the surface of the Si-star CU Virginis....Pages 350-352
Learning about stellar dynamos from long-term photometry of starspots....Pages 353-369
Starspot activity on short-period RS CVn stars....Pages 370-372
Variations in spottedness of photosphere and chromosphere of the flare star EV Lac....Pages 373-375
Surface inhomogeneities on the W UMa star AC Bootis....Pages 376-377
Long-term starspot behavior of BY Dra and EV Lac....Pages 378-380
The spot activity of FK Comae Berenices....Pages 381-383
On the existence of solar-type activity in the secondary components of cataclysmic variables....Pages 384-385
Radial velocity variability of K giants....Pages 386-388
Recent advances in the observation and analysis of stellar magnetic fields....Pages 389-400
Limits on the magnetic flux of a pre-main sequence star....Pages 401-406
Stellar zeeman analyses: Effects of multi-component atmospheres....Pages 407-410
Multi-line Zeeman analysis....Pages 411-413
A new technique to measure magnetic field strength in active stars....Pages 414-416
Magnetic flux determination in late-type dwarfs....Pages 417-419
Linear polarization and magnetic fields in cool stars....Pages 420-423
Long-term polarimetric activity of the cool supergiant µ Cephei....Pages 424-426
Polarimetric observations of active cool binaries....Pages 427-429
Magnetic fields and filling factors in late-type stars: Predictions from dynamo theory....Pages 430-434
Activity of relatively close binaries....Pages 435-439
Two kinds of activity in late-type stars....Pages 440-442
Ca II H and K and H α , and Li abundances in the pleiades late K main-sequence....Pages 443-445
Is ξ Boo AB a young or an evolved system? a model atmosphere analysis....Pages 446-448
Spectroscopic analysis of HR 1099....Pages 449-451
Recent advances in our understanding of chromospheric and coronal heating mechanisms....Pages 452-462
Ca II H high-resolution spectral monitoring of active late-type dwarfs....Pages 463-465
The onset of chromospheres in A-type stars: The altair affair....Pages 466-470
Hα and NaD line variability in RY Tauri....Pages 471-476
He I 5876 å line in the study of chromospheric activity in F-type MS stars....Pages 477-479
The age evolution of Ca II emission in late type stars....Pages 480-482
Ca II H and K spectroscopy of ER Vul....Pages 483-485
The variations of the Hα line of HD199178....Pages 486-488
Hα emission in the giant components of RS CVn systems....Pages 489-491
Spectroscopy of southern active stars....Pages 492-493
Full phase coverage of by Dra with the VLA....Pages 494-497
Coronal magnetic fields of Algol binaries from microwave spectra....Pages 498-500
On the coronal activity of RS CVn systems....Pages 501-503
Flare rate spectra as a possibility of diagnostics of convection zones in stars....Pages 504-506
Observations relating to stellar activity, magnetism and dynamos....Pages 507-514
Concluding summary: Theoretical aspects....Pages 515-521