On the main-sequence evolution of massive stars with mass loss

Theoretical isochrones, in the interval 3 to 25 106 y., have been obtained from the grid of stellar models with mass loss computed by Maeder (1980, 1981). They cover the main sequence evolution, the red supergiant region and the first blue loop. These isochrones have been compared to composite colour magnitude diagrams of young open clusters drawn by Mermilliod (1981).

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Pulsations as a mass-loss trigger in evolved hot stars

Proceedings of the International Astronomical Union ◽

10.1017/s174392131301435x ◽

2013 ◽

Vol 9 (S301) ◽

pp. 217-220

Author(s):

Michaela Kraus ◽

Dieter H. Nickeler ◽

Maximiliano Haucke ◽

Lydia Cidale ◽

Roberto Venero ◽

...

Keyword(s):

Mass Loss ◽

Main Sequence ◽

Massive Stars ◽

Sequence Evolution ◽

Hot Stars ◽

Stellar Pulsations ◽

Pass Through ◽

Mass Ejection

AbstractDuring their post-main sequence evolution, massive stars pass through several short-lived phases, in which they experience enhanced mass loss in the form of clumped winds and mass ejection events of unclear origin. The discovery that stars populating the blue luminous part of the Hertzsprung-Russell diagram can pulsate suggests that stellar pulsations might influence or trigger enhanced mass loss and eruptions. We present recent results for two objects in different phases: a B[e] star at the end of the main sequence and a B-type supergiant.

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Stellar Mass Loss and Pulsation

International Astronomical Union Colloquium ◽

10.1017/s0252921100011453 ◽

1989 ◽

Vol 111 ◽

pp. 63-82

Author(s):

L.A. Willson

Keyword(s):

Mass Loss ◽

Stellar Evolution ◽

Effective Temperature ◽

Large Amplitude ◽

Main Sequence ◽

Massive Stars ◽

Sequence Evolution ◽

Intermediate Mass ◽

Mira Variables ◽

Intermediate Mass Stars

AbstractMass loss at rates sufficient to alter the evolution of stars is known to occur during the pre-main sequence evolution of most stars, on the main sequence for massive stars, and during advanced evolutionary phases when the luminosity is high and the effective temperature is low. While most investigations of the effects of mass loss on stellar evolution have assumed continuous (parametrized) mass loss laws apply, there is increasing evidence that mass loss rates are substantially higher for stars that are pulsating with large amplitude and/or in selected modes. Some new insights into the mass loss that terminates the AGB evolution of intermediate mass stars, and leads to the formation of planetary nebulae, come from recent detailed studies of the mass loss process from the Mira variables.

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The VLT-FLAMES Tarantula Survey

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317002496 ◽

2016 ◽

Vol 12 (S329) ◽

pp. 279-286

Author(s):

Jorick S. Vink ◽

C.J. Evans ◽

J. Bestenlehner ◽

C. McEvoy ◽

O. Ramírez-Agudelo ◽

...

Keyword(s):

Mass Loss ◽

Main Sequence ◽

Massive Stars ◽

Mass Function ◽

Large Magellanic Cloud ◽

Initial Mass Function ◽

Data Set ◽

Large Program ◽

Medium Resolution ◽

Key Questions

AbstractWe present a number of notable results from the VLT-FLAMES Tarantula Survey (VFTS), an ESO Large Program during which we obtained multi-epoch medium-resolution optical spectroscopy of a very large sample of over 800 massive stars in the 30 Doradus region of the Large Magellanic Cloud (LMC). This unprecedented data-set has enabled us to address some key questions regarding atmospheres and winds, as well as the evolution of (very) massive stars. Here we focus on O-type runaways, the width of the main sequence, and the mass-loss rates for (very) massive stars. We also provide indications for the presence of a top-heavy initial mass function (IMF) in 30 Dor.

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The effects of Rotation on Wolf–Rayet Stars and on the Production of Primary Nitrogen by Intermediate Mass Stars

Symposium - International Astronomical Union ◽

10.1017/s007418090019624x ◽

2004 ◽

Vol 215 ◽

pp. 579-588 ◽

Cited By ~ 2

Author(s):

Georges Meynet ◽

Max Pettini

Keyword(s):

Star Formation ◽

Time Delay ◽

Main Sequence ◽

Massive Stars ◽

Sequence Evolution ◽

Stellar Rotation ◽

Intermediate Mass ◽

Intermediate Mass Stars ◽

Solar Metallicity ◽

Effects Of Rotation

We use the rotating stellar models described in the paper by A. Maeder & G. Meynet in this volume to consider the effects of rotation on the evolution of the most massive stars into and during the Wolf–Rayet phase, and on the post-Main Sequence evolution of intermediate mass stars. The two main results of this discussion are the following. First, we show that rotating models are able to account for the observed properties of the Wolf–Rayet stellar populations at solar metallicity. Second, at low metallicities, the inclusion of stellar rotation in the calculation of chemical yields can lead to a longer time delay between the release of oxygen and nitrogen into the interstellar medium following an episode of star formation, since stars of lower masses (compared to non-rotating models) can synthesize primary N. Qualitatively, such an effect may be required to explain the relative abundances of N and O in extragalactic metal–poor environments, particularly at high redshifts.

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The B[e] stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100004358 ◽

1989 ◽

Vol 113 ◽

pp. 117-120

Author(s):

F.-J. Zickgraf

Keyword(s):

Physical Properties ◽

Stellar Wind ◽

Main Sequence ◽

Massive Stars ◽

High Mass ◽

Sequence Evolution ◽

Two Component ◽

Show Evidence ◽

High Mass Loss ◽

General Appearance

AbstractB[e] supergiants show evidence for a non-spherical two-component stellar wind. The general appearance and the physical properties of the suggested disk-like configuration are discussed. The high mass-loss rates, the surprisingly large number and the location in the H-R diagram make these stars important for the understanding of the post-main-sequence evolution of massive stars.

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Evidence That Wolf-Rayet Stars are Pre-Mainsequence Objects

Symposium - International Astronomical Union ◽

10.1017/s0074180900044867 ◽

1991 ◽

Vol 143 ◽

pp. 53-58

Author(s):

Anne B. Underhill

Keyword(s):

Mass Loss ◽

Main Sequence ◽

Massive Stars ◽

Solar Abundances

The evidence is reviewed that Population I Wolf-Rayet stars have solar abundances, that they are surrounded by remnant disks formed from their natal clouds, and that their rate of mass loss is moderate. These properties are consistent with Wolf-Rayet stars being young objects recently arrived on the main-sequence rather than the evolved, peeled-down remnants of massive stars.

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The influence of mass loss on the evolution of binaries

International Astronomical Union Colloquium ◽

10.1017/s0252921100095087 ◽

1981 ◽

Vol 59 ◽

pp. 405-430 ◽

Cited By ~ 8

Author(s):

C. de Loore

Keyword(s):

Neutron Star ◽

Mass Loss ◽

Massive Stars ◽

Compact Object ◽

Supernova Explosion ◽

Sequence Evolution ◽

Chemical Abundances ◽

Low Mass Stars ◽

Object A ◽

The Masses

Mass loss can affect the evolution of binaries in various ways, during different stages of the evolution.1. For massive stars stellar wind mass loss will change the masses of the components during their main sequence evolution.2. During the Roche lobe overflow phase (or tidal interaction phase) matter can leave the system.3. For low mass stars matter can leave the system during the mass exchange phase and can be stored in envelopes, disks or rings.4. Sufficiently massive stars(>8-15M0) undergo at the end of their life a supernova explosion, where most of the matter is blown away and a compact object, a neutron star or a black hole can be left.5. For intermediate stars one of the components can evolve into a degenerate He or CO dwarf; a reverse mass transfer can dump matter on this degenerate dwarf. If the conditions are favorable the white dwarf can explode with loss of matter, and a neutron star can be the result.6. The chemical abundances in the outer layers change.

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Properties of massive Population III and metal-poor stars

Proceedings of the International Astronomical Union ◽

10.1017/s174392130701023x ◽

2006 ◽

Vol 2 (14) ◽

pp. 211-211

Author(s):

Daniel Schaerer

Keyword(s):

Mass Loss ◽

Power Law ◽

Main Sequence ◽

Sequence Evolution ◽

Solar Metallicity ◽

Log Normal ◽

Loss Mechanisms ◽

Population Iii

AbstractWe review the properties of massive Population III and very metal-poor stars, including briefly their formation, IMF, their main sequence evolution, possible mass loss mechanisms, atmosphere modeling etc. For detailed predictions concerning the properties of these stars we refer to Schaerer (2002) and Schaerer (2002) and references therein. Extending these calculations, Schaerer (2007) present new calculations concerning the ionizing power, Ly-α strength and related properties for different metallicities as well as for a range of power-law and log-normal IMFs. For illustrations from these studies see the Figures below. New detailed calibrations for solar metallicity O-type stars have recently been presented by Martins et al. (2005).

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