Highlights of Astronomy: Part II As Presented at the XVIth General Assembly 1976

Front Matter....Pages I-7
Front Matter....Pages 1-7
Introductory Remarks....Pages 9-10
Discussion....Pages 37-39
M Dwarfs at Lower z Distances....Pages 11-19
Available Stellar Data in Galactic Polar Areas....Pages 21-22
Bibliography on Galactic Structure in the Direction of Polar Caps....Pages 23-24
M Dwarfs and the Missing Mass....Pages 25-25
Some Research Programmes into Galactic Structure at the Galactic Caps under Way at the Royal Greenwich Observatory....Pages 27-28
The Space Density of M Dwarfs — An Observational Program....Pages 29-30
The Luminosity Function of Late-Type Main-Sequence Stars in the Direction of the North Galactic Cap....Pages 31-31
Galactic Mass Density in the Vicinity of the Sun....Pages 33-33
The Frequency of Faint M Giant Stars at High Galactic Latitudes....Pages 35-36
The Stellar Distribution Above the Galactic Plane: An Introduction....Pages 41-48
Some Results of Classification of Stars in Kapteyn Areas Applied to Galactic Structure in NGP....Pages 49-50
Mean Chemical Abundance of the F Stars as a Function of Distance from the Galactic Plane....Pages 51-52
RGU Three-Colour-Photometry Towards the North Galactic Pole: Halo-To-Disk Mass Ratio....Pages 53-54
Density Law, Vertical Distribution and Vertical Gradient of Metal Abundances for G and K Giants....Pages 55-55
Polarization Measurements and Extinction Near the NGP....Pages 57-58
Parallaxes of Selected Stars Near the North Galactic Pole....Pages 59-60
Progress Report on a Search for Parallax Stars in the Region of the South Galactic Cap....Pages 61-61
Search for Large Radial Velocities in Direction of NGP Using the Fehrenbach Techniques....Pages 63-63
Front Matter....Pages 1-7
Discussion....Pages 87-87
The Gravitational Field of the Galaxy in the Z Direction....Pages 65-66
Berkeley Studies of Faint Stars at High Latitudes....Pages 67-67
Swedish Programmes Concerning the Z Distribution of Stars....Pages 69-69
Studies of A and F Stars in the Region of the North Galactic Pole....Pages 71-71
The Distribution of Field Horizontal-Branch Stars in the Galactic Halo....Pages 73-74
A New Program to Determine K(z) from Main Sequence Stars....Pages 75-76
Objective-Prism Radial Velocities at High Latitudes....Pages 77-77
Discussion of the Calculation of the Density Law (Dz)....Pages 79-82
Motions of Near-Polar K-Giants Along the Z-Coordinate....Pages 83-86
The Role of Proper Motions in Determining the Luminosity and Density Functions....Pages 89-93
Concluding Remarks Part II....Pages 95-96
Current Results and Suggestions for Future Work....Pages 97-98
Front Matter....Pages 99-101
Introductory Talk....Pages 103-104
Observational Evidence for Atmospheric Physical Characteristics Relevant to Stellar Evolution....Pages 105-114
Behaviour of Microturbulence with Evolution....Pages 115-118
Observational Evidence for Atmospheric Chemical Composition Peculiarities Relevant to Stellar Evolution....Pages 119-135
Sensitivity of Internal Structure to the Surface Boundary Condition....Pages 137-142
Boundary Conditions with Mass-Loss: General Considerations....Pages 143-154
Mass Loss in Stars of Moderate Mass by Stellar Winds and Effects on the Evolution....Pages 155-173
Front Matter....Pages 99-101
Boundary Condition with Mass Loss: The Radiatively-Driven Wind Model....Pages 175-175
Stratification of Elements in a Quiet Atmosphere: Diffusion Processes....Pages 177-191
Competition Between Diffusion Processes and Hydrodynamical Instabilities in Stellar Envelopes....Pages 193-203
Mixing Between Burned Core Material and Surface Layers....Pages 205-208
Decay of Light Elements in Stellar Envelopes....Pages 209-216
Conclusion....Pages 217-218
Front Matter....Pages 219-221
Observations of Small-Scale Photospheric Magnetic Fields....Pages 223-239
Small Scale Solar Magnetic Fields: Theory....Pages 241-250
Some Comments on the Measurement of Small Scale Strong Magnetic Fields on the Sun....Pages 251-254
Line Profiles of Faculae and Pores....Pages 255-260
Facular Models, the K-Line, and Magnetic Fields....Pages 261-264
Small Magnetostatic Flux Tubes....Pages 265-266
Flows in Magnetic Flux Tubes....Pages 267-270
Discussion....Pages 271-272
Concluding Remarks....Pages 273-275
Front Matter....Pages 277-279
Introduction....Pages 281-281
Present Status of Spectral Classification in the Conventional Wavelength Range with Emphasis Upon Early-Type Stars....Pages 283-288
Spectral Classification of Early Type Stars from the Low Dispersion Ultraviolet Spectra....Pages 289-301
Spectral Classification of B and A Stars from the Line Features of S2/68 Spectra....Pages 303-303
Behaviors of B Star Continua and Absorption Features Determined from the TD1 S2/68 “Ultraviolet Bright Star Spectrophotometric Catalogue” and from Copernicus Spectra....Pages 305-305
Front Matter....Pages 277-279
Discussion....Pages 307-309
Spectral Classification Using ANS Photometric Data....Pages 311-313
Spectral Classification with Objective-Prism Spectra from Skylab....Pages 315-322
Discussion....Pages 323-324
An Atlas of Ultraviolet Stellar Spectra....Pages 325-337
A New Temperature Scale for B Stars Based on OAO-2 Data....Pages 339-339
Extreme Ultraviolet Observations of White Dwarfs....Pages 341-347
The Near Ultraviolet Spectrum of Fe III as a Classification Criterion....Pages 349-351
A Catalogue of 0.2 Å Resolution Far-Ultraviolet Stellar Spectra Measured with Copernicus....Pages 353-354
Spectral Classification from Copernicus Data....Pages 355-359
The Ultraviolet Spectrum of Beta Lyrae....Pages 361-362
The Mg II Features Near 2800Å and Spectral Classification....Pages 363-364
Discussion....Pages 365-366
Concluding Remarks....Pages 367-369
Front Matter....Pages 371-375
Heterogeneity of the Solar Atmosphere....Pages 377-387
The Heterogeneity of Surfaces of Magnetic Ap Stars....Pages 389-394
Starspots on by DRA-Type Stars....Pages 395-396
Star Spots on Ar Lac Type Stars....Pages 397-403
Direct Observations of the Heterogeneity of Supergiant Disks....Pages 405-405
On the Spottedness and Magnetic Field of T Tau-Type Stars....Pages 407-407