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Author name code: deinzer
ADS astronomy entries on 2022-09-14
author:"Deinzer, Willi"
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Title: On the post main sequence expansion of stars with contracting
helium cores
Authors: Schrinner, M.; Deinzer, W.
2001A&A...379..496S Altcode:
The post main sequence expansion of a (5 M<SUB>solar</SUB>)-star
is investigated by means of a simple composite configuration: a
contracting He-core of Schoenberg-Chandrasekhar mass surrounded by
an H-envelope of polytropic index (n=3). While the structure of the
envelope is immediately obtained by solving the equations of hydrostatic
equilibrium, the core requires some further simplification: if the
actual non-local gravitational energy release due to contraction is
replaced by its constant core-average, the equation of radiative energy
transport may be easily integrated. Thus an explicit relation between
pressure and temperature is obtained and the equations of hydrostatic
equilibrium may be solved. Specifying (M,M<SUB>core</SUB>) and
(T<SUB>0</SUB>) (the temperature of the H-burning shell-source at the
interface), a sequence of models follows with (L<SUB>core</SUB>), the
gravitational energy released from the core per second, and hence with
t, the contraction time, as the parameter. The resulting simple models
show very rapid expansion, a consequence of the thermostatic action
of the shell-source. Its fixed temperature prevents the shell-source
from participating in the contraction of the core - thus causing the
outer parts of the core and hence the adjoining envelope to decrease
in density. Accordingly, the envelope must expand. This consequence
of a fixed temperature (T<SUB>0</SUB>) is clearly demonstrated by the
distributions of the specific internal and gravitational energies. This
characteristic behaviour is also found in stellar models obtained by
elaborate numerical simulations.
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Title: On the POST main sequence expansion of low mass stars
Authors: Deinzer, W.
1999A&A...342..704D Altcode:
The post main sequence expansion of stars is investigated by means of
a simple composite configuration: an isothermal He-core (allowing for
non-relativistic electron degeneracy) is surrounded by a H-envelope
of constant density (polytrope \(n=0 \)). Solving the equations of
hydrostatic equilibrium for fixed values of total mass and temperature
at the interface a one dimensional sequence of models is obtained
with the mass of the core as parameter. As soon as the main part of
the core becomes fully degenerate, the model stars expand rapidly. This
behaviour is in good agreement with that of models obtained by numerical
simulations. The expansion is caused by an intermediate non-degenerate
layer of large extension (but of very small mass content) just below
the interface. It shifts the envelope to larger distances from the
center and thus reduces the gravitational pull on it due to the highly
contracted part of the core. Without this layer the thermal forces
of the envelope - determined by the hydrogen burning temperatures at
the interface - would be much too small to balance gravity. Such a
loosely bound envelope extends to the large radii in question. Hence,
the model suggests the fixed temperature required by hydrogen burning
to be the ultimate reason for the post main sequence expansion.
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Title: Sunspots
Authors: Deinzer, W.
1994smf..conf...13D Altcode:
No abstract at ADS
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Title: A flux tube-model for solar prominences
Authors: Degenhardt, U.; Deinzer, W.
1993A&A...278..288D Altcode:
Quiescent prominences are modeled as a sequence of slender static
flux tubes arranged behind each other and embedded in an isothermal
corona. We take into account a simple energy equation which describes
the balance between radiative losses and mechanical heating while
neglecting heat conduction. This leads to a polytropic relation for the
prominence plasma. Solutions of the equations describing the large-scale
mechanical equilibrium and the simplified energy balance of a single
flux tube are determined. The general behavior of the solutions can be
described analytically. Only the explicit path of the flux tube has to
be determined by numerical integration. Numerical values of temperature
and density are well within the ranges observed in prominences.
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Title: Torus dynamos for galaxies and accretion disks. I. The
axisymmetric alpha omega-dynamo embedded into vacuum.
Authors: Deinzer, W.; Grosser, H.; Schmitt, D.
1993A&A...273..405D Altcode:
Accretion disks around compact objects as well as the gaseous
components in galaxies often have the form of a torus. To study the
structure and behaviour of magnetic fields generated in such rings,
a kinematic α ω-dynamo is investigated which is working inside a
torus embedded into vacuum. The axisymmetric dynamo equations are
solved by series expansion into exponential decay modes of slender
tori, which are available analytically. A linear, homogeneous system
of equations follows for the expansion coefficients: its eigenvalues
determine the time-dependence of the dynamo solutions. Modes symmetric
and antisymmetric with respect to the equatorial plane are obtained
separately. The results are presented for different excitation
conditions. By far the most easily excited dynamo mode is stationary
and of quadrupolar symmetry. This basic mode appears for negative
dynamo numbers and could he responsible for the axisymmetric field
observed in spiral galaxies like M 31 or IC 342. Quadrupolar modes for
positive dynamo numbers as well as all excited dipolar modes are of
an oscillatory nature. They need considerably stronger excitation than
the stationary solution and are not expected under galactic conditions,
but they might play a role in accretions disks around compact objects.
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Title: Dynamo-Action in Accretion Disks
Authors: Deinzer, W.
1993IAUS..157..185D Altcode:
No abstract at ADS
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Title: Meine Begegnung mit Cuno Hoffmeister.
Authors: Jensch, A.; Kippenhahn, R.; Deinzer, W.; Schubart, J.; Geyer,
E. H.; Eichhorn, M.; Busch, H.
1992cuho.book...83J Altcode:
No abstract at ADS
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Title: On the treatment of the non-axisymmetric torus-dynamo.
Authors: Deinzer, W.
1991NAWG.1991...21D Altcode:
No abstract at ADS
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Title: Torus-Dynamo
Authors: Deinzer, W.; Grosser, H.; Schmitt, D.
1990IAUS..140...95D Altcode:
A toroidal dynamo in a vacuum is examined theoretically to investigate
the structure and behavior of magnetic fields in toroidal accretion
disks encircling compact objects and gaseous components. The equations
for a kinematic, axisymmetric alpha-omega dynamo, in toroidal form,
are solved to determine the dynamo modes for different torus sizes and
varying excitation conditions. The results are given, and the stationary
dynamo mode with quadrupolar symmetry is found to be the most easily
excited mode, and excitation conditions are related primarily to
torus thickness.
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Title: A review of: "Exercises in astronomy"
Authors: Deinzer, W.
1989GApFD..46..267D Altcode:
By J. Kleczek. D. Reidel Publishing Company, xxiii+339 pp., us 64
(ISBN 90-277-2409-1), Paperback Edition US19.50 (ISBN 90-277-2423-7).
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Title: Generation of Magnetic Fields in Gaseous Rings
Authors: Deinzer, W.; Grosser, H.; Schmitt, D.
1989AGAb....3..108D Altcode:
Accretion disks around compact objects as well as the gaseous components
in galaxies often have the form of a torus. A dynamo model is applied
to this configuration to determine the structure and behaviour of
magnetic fields generated in such rings. The equations for the kinematic
alpha-Omega-dynamo are written down in toroidal coordinates. They are
solved by series expansion into the exponential decay modes of slender
tori, which are available in analytical form. A linear, homogeneous
system of equations follows for the expansion coefficients; its
eigenvalues determine the time-dependence of the solutions, the dynamo
modes. Modes symmetric and antisymmetric with respect to the equatorial
plane are obtained separately. The results are presented for different
excitation conditions, i.e. dynamo numbers. By far the most easily
excited dynamo mode is stationary and of quadrupolar symmetry. This
basic mode appears for negative dynamo numbers. Quadrupolar modes
for positive dynamo numbers as well as all excited dipolar modes are
of oscillatory nature. They need considerably higher excitation than
the stationary solution. The fields of oscillating dynamos evolve in
vertical direction along the surfaces of constant rotation, which are
cylinders in this investigation. The spatial distribution of alpha and
the thickness of the torus do not seem to be of much importance for
the results. This project only deals with the axisymmetric case. The
observation of bisymmetric fields in a couple of spiral galaxies calls
for non-axisymmetric investigations. Also alpha^2-dynamos might be
of importance for the generation of strong poloidal fields found in
the center of our Galaxy and in the nucleus of mildly active edge-on
galaxies. These fields seem to be connected with partially ionized
gaseous rings surrounding the nucleus.
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Title: Joint Discussion on Topics of Session 11
Authors: Deinzer, W.
1987rfsm.conf..328D Altcode:
No abstract at ADS
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Title: Small Scale Magnetic Flux Concentrations in the Solar
Photosphere
Authors: Deinzer, W.; Knölker, M.; Voigt, H. H.
1986ssmf.conf.....D Altcode: 1986ssmf.book.....D
No abstract at ADS
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Title: Model calculations of magnetic flux tubes. I - Equations and
method. II - Stationary results for solar magnetic elements
Authors: Deinzer, W.; Hensler, G.; Schuessler, M.; Weisshaar, E.
1984A&A...139..426D Altcode:
The equations, boundary conditions, geometry, approximations, and
numerical methods used in model studies of the physics of magnetic flux
tubes in stellar convection zones and atmospheres are presented. The
methods described are then used to study the smallest flux tubes in
the solar atmosphere, i.e., the magnetic elements that are thought to
be responsible for facular points and filigree. The models proposed
here are dynamical and include flows; the material properties (e.g.,
opacity and heat capacity) are calculated self-consistently. Although
many limitations remain, it is shown that a considerable contribution
to the understanding of the physics of photospheric flux concentrations
can be made even at this level of sophistication. In addition, models of
stationary magnetic flux elements are presented which are considered to
constitute the basic structure of the solar photospheric magnetic field.
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Title: Model Calculations of Magnetic Flux Tubes - Part Two -
Stationary Results for Solar Magnetic Elements
Authors: Deinzer, W.; Hensler, G.; Schussler, M.; Weisshaar, E.
1984A&A...139..435D Altcode:
Based on the methods of a preceding paper (Deinzer et al., 1984) we
present models of stationary magnetic flux elements which are thought
to build the basic strncture of the solar photospheric magnetic
field. The main results are: a) A model with a density reduction to
half of the ambient value and a reduction of the vertical convective
transport coefficient by a factor 0.2 is well comparable with the semi-
empirical model of Chapman (1979). b) The tube is surrounded by a
dark region of gas which is significantly cooler than the undisturbed
photo sphere at the same height. This reduces the "hot wall effect"
and points to the necessity of an additional heating process for the
upper layers of the flux tube atmosphere. c) The inclination of the
isotherms with respect to the lines of constant gravitational potential
in the nonmagnetic surroundings of the tube leads to a downflow around
the magnetic strncture with a velocity of ∼ 1 km s<SUP>-1</SUP>. d)
The energetics of the observable layers (τ ≍ 1) of the tube is
dominated by horizontal radiative influx. Convective transport along
the tube plays a secondary role.
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Title: Self-consistent models for small photospheric flux tubes
Authors: Deinzer, W.; Hensler, G.; Schmitt, D.; Schuessler, M.;
Weisshaar, E.
1983IAUS..102...67D Altcode:
The present investigation is concerned with results of a numerical study
of magnetic field concentrations in the solar photosphere and upper
convection zone. A two-dimensional time dependent code was developed
for the full MHD equations in slab geometry for a compressible medium,
taking into account the momentum equation, the equation of continuity,
the induction equation for infinite conductivity, and the energy
equation. A finite-element technique is used in the development
procedure. Attention is given to the description of convective energy
transport by the mixing-length formalism, a nearly static flux tube
model, and the use of the two-dimensional radiative transfer code of
Mihalas et al. (1978) for LTE diagnostics of the radiation field.
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Title: Modelle photosphärischer Magnetfeld-Konzentrationen
Authors: Deinzer, W.; Hensler, G.; Schmitt, D.; Schüssler, M.;
Weisshaar, E.
1982MitAG..55...65D Altcode:
No abstract at ADS
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Title: The Sun as a star
Authors: Deinzer, W.
1981ESASP.164...25D Altcode: 1981sse..conf...25D
The Sun and the theory of stellar structure, solar rotation, the solar
cycle, and the solar magnetic field are discussed. The validity of solar
models which adjust Prandtl's mixing length and helium abundance so
that radius and luminosity match their solar values is tested. The
fragmentary state of turbulence theory prevents investigation
of the hydrogen convection zone from providing quantitative
validation. Evidence based on solar neutrino flux and nonradial
solar oscillations is not decisive. The transport of angular momentum
towards the equator, resulting in differential rotation, could be due to
anisotropic viscosity caused by turbulent eddies in the convection zone,
Rossby waves, or convection. The pairwise appearance of sunspots and
their migration towards lower latitudes are accounted for in numerical
solutions of the modified induction equation. These show that strong
toroidal flux tubes, of opposite sign in each half cycle, are produced.
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Title: Dynamo action associated with random waves in a rotating
stratified fluid
Authors: Walder, M.; Deinzer, W.; Stix, M.
1980JFM....96..207W Altcode:
A random superposition of waves in a rotating, stratified, electrically
conducting fluid leads to dynamo action in the sense that it yields a
mean electric field having a component parallel to the mean magnetic
field ('alpha-effect'). Using Fourier analysis methods, an explicit
expression for the mean electric field is derived. The alpha-effect
has tensor form. A finite alpha-tensor even in a case of vanishing
mean helicity is obtained. The result is discussed in the context of
the solar turbulent dynamo.
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Title: Dynamowirkung von Schall- und Schwerewellen in geschichteten,
rotierenden Atmosphären
Authors: Wälder, M.; Deinzer, W.; Stix, M.
1979MitAG..45...95W Altcode:
No abstract at ADS
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Title: Stellar Dynamos
Authors: Deinzer, W.
1976IAUTB..16..241D Altcode: 1976IAUT...16B.241D
No abstract at ADS
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Title: Induktionswirkung turbulenter Materie
Authors: Deinzer, W.
1976MitAG..40..156D Altcode:
No abstract at ADS
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Title: Controversial Theories: Accretion VS. Diffusion Theory,
Dynamo VS. Fossil Fields
Authors: Deinzer, W.
1976paps.coll..713D Altcode: 1976IAUCo..32..713D
No abstract at ADS
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Title: Steady and Oscillatory aw-dynamos
Authors: Deinzer, W.; von Kusserow, H. -U.; Stix, M.
1974A&A....36...69D Altcode:
Summary. Using the model of Deinzer and Stix (1971) of an occo-dynamo
we investigate the problem whether the preferred magnetic field mode
is steady or oscillatory for any particular strength and spatial
distribution of the induction effects (oc-effect and non-uniform
rotation). We find that a spatial separation of these two effects
favours the steady modes, in contrast to an earlier assertion
of Steenbeck and Krause (1969a). The steady modes have dipoletype
symmetry if the dynamonumber is positive, and quadrupoletype symmetry
if the dynamo number is negative. The possible relevance of the steady
dipole solutions to the dynamo operating in the Earth's interior is
discussed. Key words: dynamo - oc-effect - differential rotation -
geomagnetism
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Title: Universitäts-Sternwarte Göttingen mit Institut für
Sonnenforschung Locarno-Orselina (Tessin). Report 1973.
Authors: Deinzer, W.; Kippenhahn, R.; Schröter, E. H.; Voigt, H. H.
1974MitAG..35...66D Altcode:
No abstract at ADS
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Title: A Model for the Magnetic Field of the Magellanic System
Authors: Deinzer, W.; Schmidt, Th.
1973A&A....27...85D Altcode:
Summary. A model is presented for the gaseous bridge and for the
magnetic field connecting both Magellanic Clouds, according to optical
and radio observations. Since an equilibrium configuration seems
unlikely the time dependent problem has been considered. Assuming
cylindrical symmetry, a similarity solution of the equations of
induction, of continuity and of motion has been found. The resulting
time history of the Magellanic Bridge is summarized in Table 2, taking
the observational data from Hindman et aL (1963). A magnetic field of
10 6 Gauss, as suggested by observations, gives an age of 108 years
for the configuration, during which an expansion by about a factor 2
occurred. Key words: Magellanic Clouds - magnetic field model
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Title: Gibt es auch stationäre αω-Dynamos?
Authors: Deinzer, W.; v. Kusserow, H. U.; Stix, M.
1973MitAG..34..155D Altcode:
No abstract at ADS
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Title: Universitäts-Sternwarte Göttingen mit Institut für
Sonnenforschung Locarno-Orselina (Tessin). Report 1971.
Authors: Deinzer, W.; Kippenhahn, R.; Schröter, E. H.; Voigt, H. H.
1972MitAG..31..285D Altcode:
No abstract at ADS
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Title: Zum Magnetfeld der Magellanschen Wolken
Authors: Deinzer, W.; Schmidt, Th.
1972MitAG..31..177D Altcode:
No abstract at ADS
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Title: Schwingungsphänomene in der Astrophysik.
Authors: Deinzer, W.
1972NAWG.1972..146D Altcode:
No abstract at ADS
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Title: On the Eigenvalues of Krause-Steenbeck's Solar Dynamo
Authors: Deinzer, W.; Stix, M.
1971A&A....12..111D Altcode:
The complex eigenvalues of the Krause-Steenbeck dynamo are evaluated
making simplified assumptions about the basic effects. The differential
rotation of the sun, producing toroidal components in an originally
meridioiial magnetic field, is approximated by a step-function, with the
discontinuity at 0.7 B; the " effect", producing meridional components
in an originally toroidal magnetic field, is approximated by a 8junction
at 0.85 B. For a vanishing effect only real eigenvalues are obtained
- corresponding to modes decaying exponentially with time. As the
effect increases some of the eigenvalues are shifted into the complex
region - eorresponding to oscfflatory modes. If their amplitudes are
increasing exponentially with time, the dynamo is "excited". Applying
the results to the sun, the only excited mode has an oscfflation period
of 2 years. Non-linear effects, necessary to limit the exponentially
increasing amplitudes, are discussed briefly. Key words: solar magnetic
cycle - dynamo theory - eigenvalue problems
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Title: Universitäts-Sternwarte Göttingen und Institut für
Sonnenforschung Locarno-Orselina (Tessin). Report 1970.
Authors: Deinzer, W.; Kippenhahn, R.; Schröter, E.; Voigt, H. H.
1971MitAG..29...55D Altcode:
No abstract at ADS
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Title: Zur Theorie des solaren Magnetfeldes
Authors: Deinzer, W.
1971MitAG..30...67D Altcode:
No abstract at ADS
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Title: Warum expandieren Sterne nach Verlassen der Hauptreihe?
Authors: Deinzer, W.; Krummheuer, F.
1970NW.....57..392D Altcode:
No abstract at ADS
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Title: The Evolution of a Red Giant after Rapid Mass Loss, and the
Harman-Seaton Sequence
Authors: Deinzer, Willi; von Sengbusch, Kurt
1970ApJ...160..671D Altcode:
The evolution of a stellar model is investigated numerically in order
to account for the consequences of mass loss preceding the observed
evolution of the central stars of planetary nebulae. A red giant of
1.3 Mo is stripped of almost all of its envelope, and hydrostatic
equilibrium is restored by quasi-static, adiabatic expansion. The
evolution of this model depends on the mass that remains in the
envelope. If > 1(Y- , thermal equilibrium is restored, i.e., after
the thermal-relaxation phase, the luminosity of the stellar model is
produced entirely by the hydrogen-burning shell source. If AM /M <
10- thermal equilibrium cannot be restored, and after evolving through
a luminosity maximum the model becomes a white dwarf. The evolutionary
tracks obtained in the latter case are compared wfth the Harman-
Seaton sequence.
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Title: Universitäts-Sternwarte Göttingen, Institut für
Sonnenforschung Locarno-Orselina (Tessin). Report 1969.
Authors: Deinzer, W.; Kippenhahn, R.; Schröter, E.; Voigt, H. H.
1970MitAG..28...53D Altcode:
No abstract at ADS
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Title: Fast Evolution Towards the White Dwarfs
Authors: Deinzer, W.; Hansen, C. J.
1969A&A.....3..214D Altcode:
Four evolutionary sequences of stellar models have been investigated
numerically to improve upon an earlier attempt by Deinzer to explain
some puzzling features in the evolution of the central stars of
planetary nebulas. The present models consist of highiy contracted,
semi-degenerate, isothermal cores containing a large fraction of
the stellar mass, and radiative envelopes of very small mass content
which are capable of large contractions within short time-scales. The
evolutionary track of sequence I is very similar to the track obtained
earlier by Deinzer under the same starting conditions, but with certain
simplifying assumptions. The evolutionary time-scale of sequence I,
however, is much shorter than the 10 years estimated in the earlier
paper, if the envelope contains only 10- of the total mass. Models
with envelopes containing a few percent of the stellar mass are shown
to evolve at about the desired time-scale of 10 years (Sequences II
and III). Sequence IV, starting from a model in which the luminosity
transported throughout the envelope decreases towards the outside (in
the preceding cases it was assumed to be constant), has an increase
in luminosity before descending towards the white dwarf state, thus
becoming topologically similar to the empirical sequence.
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Title: Weiße Zwerge, Neutronensterne und der Endzustand der Materie.
Authors: Deinzer, W.
1969S&W.....8..224D Altcode:
No abstract at ADS
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Title: On the Evolution of the Central Stars
Authors: Deinzer, W.
1968IAUS...34..428D Altcode:
No abstract at ADS
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Title: On the Evolution of the Central Stars of Planetary Nebulae.
Authors: Deinzer, Willi; Hansen, Carl
1968AJS....73S.173D Altcode:
72, 813,1967), a planetary nebula should be formed during a phase of
rapid mass loss of a red giant due to the dynamical instability of
its convective envelope. To stimulate the effect of rapid mass loss
on the internal structure of a red giant, a star of 1.3 Mo at a phase
shortly before helium flash (Thomas, H. C., Z. Astrophys. 67, 420,1967)
was stripped of almost all of its envelope. Hydrostatic equilibrium
of the remaining star of 0.54 Mo was restored by quasi- static,
adiabatic expansion. This affects only the outermost layers above the
shell source and yields a temperature gradient 0.25 <d logT/d logP
<(d logT/d logP) ad ~O that luminosity decreases outward. Subsequent
restoration of thermal equilibrium leads to two different possibilities:
If the fractional mass left in the stellar envelope is > 2 X 10-~
the star reaches an equilibrium state in which the hydrogen-burning
shell source supplies the required luminosity; if the fractional
mass of the envelope is ~ 1 X lO-~, the shell source is not able to
supply the required luminosity, in which case after evolving through
maxima in radius and luminosity the star becomes a white dwarf. The
evolutionary tracks obtained in the latter case are similar to the
Harman-Seaton sequence. The luminosity maximum, however, is by a factor
10 smaller than the maximum luminosity in the Harman-Seaton sequence
and the evolutionary time scale (equal to the thermal time-scale)
is by a factor 100 too fast. The latter has to do with the fact, that
evolution towards white dwarfs in the case of a hydrogen-burning shell
source results only for a very small mass content of the envelope. From
the results of L'Fcuyer (Astrophys. J. 146, 845, 1966) it is inferred
that an analogous evolution starting from an originally helium-burning
shell source model should occur for a fractional mass 0.1 of the
envelope. Hence thermal time scales should increase accordingly.
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Title: Zur Entwicklung der Zentralsterne planetarischer Nebel
Authors: Deinzer, W.
1968MitAG..25..225D Altcode:
No abstract at ADS
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Title: Zur Entwicklung der Zentralsterne planetarischer Nebel
Authors: Deinzer, W.
1967ZA.....67..342D Altcode:
No abstract at ADS
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Title: Atmosphären von Zentralsternen planetarischer
Nebel. II. Modellatmosphären für die O'Dell- und die
Harman-Seaton-Sequenz
Authors: Böhm, K. H.; Deinzer, W.
1966ZA.....63..177B Altcode:
No abstract at ADS
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Title: Models for Carbon-Burning Stars.
Authors: Deinzer, W.; Salpeter, E. E.
1965ApJ...142..813D Altcode:
Equilibrium models are constructed for stars containing only C12 and
heavier elements. An "initial carbon-burning main sequence"is found both
with and without neutrino energy loss mechanisins The neutrinos raise
the central temperature T about 25 per cent, decrease the lifetime by
a factor of more than 100, increase the extent of the convective core,
decrease the optical luminosity slightly, and raise the minimum mass
for carbon burning from 0 7 Mo to about 0 8 Mo. For gravitationally
contracting stars, neutrino processes become important when T exceeds
0.3 or 0.5 X 10 K; they lower the temperature gradient (or even reverse
its sign) in the deep interior and the contraction is not homologous.
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Title: On the Magneto-Hydrostatic Theory of Sunspots.
Authors: Deinzer, Willi
1965ApJ...141..548D Altcode:
Theoretical sunspot models are constructed which are a generalization
of those considered by Schltiter and Temesvary (1958). A non-vanishing
horizontal component of the pressure gradient, as required by
magneto-hydrostatic equilibrium, is obtained by assuming that a
magnetic field in the solar hydrogen convection zone (HCZ) inhibits
the convective-energy transport. In the framework of Prandtl's
mixing- length theory, this is achieved by making the ratio of the
mixing length, t, and the pressure scale height, H, smaller in the
magnetic-field region than in the surrounding undisturbed HCZ. The
corresponding system of ordinary differential equations was solved
numerically, and pressure, temperature, and magnetic-field strength
along the axis of symmetry were obtained. When t/H ranges from zero to
(t/H) cz a one-parameter family of solutions results; in the one extreme
convecflve-energy transport is completely suppressed; in the other
extreme there is no inhibition of convective-energy transport. From
this family of models, relations between the coolness of a spot and
its magnetic-field strength and between the magnetic-field strength
and 1/H are derived. The former relation agrees with observations
to within 50 per cent; the latter indicates a maximum possible field
strength of about 5000 gauss.
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Title: Atmosphären von Zentralsternen Planetarischer Nebel I. Mit
5 Textabbildungen
Authors: Böhm, K. H.; Deinzer, W.
1965ZA.....61....1B Altcode:
No abstract at ADS
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Title: Equilibrium Models for Helium-Burning Stars.IV. Massive Stars
and Nuclear Abundances.
Authors: Deinzer, W.; Salpeter, E. E.
1964ApJ...140..499D Altcode:
Equilibrium models are constructed for pure helium-burning stars of
large mass M, where radiation pressure is important (for smaller masses
see the preceding paper). The approach of extremely massive models to
fully convective polytropes with n = 3 is discussed. The early evolution
of our models from the initial helium-burning "main sequence" has been
followed till the mass fraction Xa of helium in the convective core is
0.02. The abundances of C", Oi6, Ne'0, and Mg'4 as a function of Xa were
calculated for different masses M. The main flnal products are C and
0 for M < 4 (in solar units), 0 for M 10 to 100, and Mg for M 10'
to 10'. The final abundance of Ne is for all masses When Xa is small,
the energy production is largely from (a, ) reactions and enhancement
factors for the rate E (over that for the triple-alpha reaction alone)
are presented.
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Title: A magneto-hydrostatic sunspot model
Authors: Deinzer, W.
1964susp.conf..236D Altcode:
No abstract at ADS
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Title: Zur magneto-hydrostatischen Theorie der Sonnenflecken
Authors: Deinzer, Willi
1963zmht.book.....D Altcode:
No abstract at ADS
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Title: Zur magneto-hydrostatschen Theorie der Sonnenflecken Title:
Zur magneto-hydrostatschen Theorie der Sonnenflecken
---------------------------------------------------------
Title: On the
magneto-hydrostatic theory of sunspots;
Authors: Deinzer, Willi
1962PhDT........46D Altcode:
No abstract at ADS
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Title: Die Lichtkurve des Bedeckungsveränderlichen BV 143 = BD +
35&deg 4496. Mit 1 Textabbildung
Authors: Deinzer, W.; Geyer, E.
1959ZA.....47..211D Altcode:
No abstract at ADS
