Powered by OpenAIRE graph
Found an issue? Give us feedback
addClaim

This Research product is the result of merged Research products in OpenAIRE.

You have already added 0 works in your ORCID record related to the merged Research product.

Stellar rotation effects on the stellar winds

Authors: B. K. Shivamoggi;

Stellar rotation effects on the stellar winds

Abstract

The purpose of this paper is to give detailed systematic considerations to clarify and provide insights and a qualitative guide into the role of the azimuthal wind flow in the stellar-rotation braking mechanism. For this purpose, we make use of the Weber-Davis [Astrophys. J. 148, 217 (1967)] magnetohydrodynamic (MHD) version of Parker's [Astrophys. J. 128, 664 (1958)] stellar wind model. For the case when the magnetic field is primarily radial (as that near the surface of a star), the Weber-Davis [Astrophys. J. 148, 217 (1967)] “slow” magnetosonic critical point becomes Parker's [Astrophys. J. 128, 664 (1958)] sonic critical point, and the azimuthal wind flow can be approximated by corotation. Stellar rotation is shown to cause the sonic critical point to occur lower in the corona, and so the stellar wind experiences a stronger “afterburner” (as in an aircraft jet engine) action in the corona. Our results show that stellar rotation leads to considerably enhanced stellar wind acceleration even for moderate rotators like the sun. On the other hand, the stellar wind is shown to experience an immensely enhanced acceleration in a narrow shell near the star for strong rotators. This is underscored by the sonic critical point occurring considerably lower in the corona for strong rotators, hence supporting a huge afterburner action in the corona for such stars. For strong rotators, this sonic critical point is shown to be determined only by the basic stellar parameters such as mass M and angular velocity Ω∗, which signify the dominance of centrifugal and magnetic drivings in accelerating the stellar wind for such stars. Stellar rotation causes the physical throat section of the effective “de Laval” nozzle associated with the stellar wind flow to become narrower and the nozzle to also have a larger flare, indicative of an enhanced flow acceleration. The de Laval nozzle analogy does not, however, comply with the density drop in the stellar wind correctly. Thus, stellar rotation leads to tenuous and faster stellar wind flows without changes in the mass flux and hence enables protostars and strong rotators to lose their angular momentum quickly.

Related Organizations
  • BIP!
    Impact byBIP!
    selected citations
    These citations are derived from selected sources.
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    3
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
Powered by OpenAIRE graph
Found an issue? Give us feedback
selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
3
Average
Average
Average
Upload OA version
Are you the author of this publication? Upload your Open Access version to Zenodo!
It’s fast and easy, just two clicks!