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The Origin of Nonradiative Heating/Momentum in Hot Stars

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The Origin of Nonradiative Heating/Momentum in Hot Stars NASA Conference Publication 2358 NASA-CP-2358 19850009446 The Origin of Nonradiative Heating/Momentum in Hot Stars Proceedings of a workshop held at NASA Goddard Space Flight Center Greenbelt, Maryland June 5-7, 1984 NI_SA NASA Conference Publication 2358 The Origin of Nonradiative Heating/Momentum in Hot Stars Edited by A. B. Underhill and A. G. Michalitsianos Goddard Space Flight Center Greenbelt, Maryland Proceedings of a workshop sponsored by the National Aeronautics and Space Administration, Washington, D.C., and the American Astronomical Society, Washington, D.C., and held at NASA Goddard Space Flight Center Greenbelt, Maryland June 5-7, 1984 N/LS/X NationalAeronautics and SpaceAdministration ScientificandTechnical InformationBranch J 1985 TABLE OF CONTENTS ORGANIZING COMMITTEE v LIST OF PARTICIPANTS vi OPENING REMARKS A.B. Underhill I SESSION I. - EVIDENCE FOR NONRADIATIVE ACTIVITY IN STARS EVIDENCE FOR NONRADIATIVE ACTIVITY IN HOT STARS J.P. Cassinelli (Invited review) 2 EVIDENCE FOR NON-RADIATIVE ACTIVITY IN STARS WITH Tef f < i0,000 K Jeffrey L. Linsky (Invited review) 24 OBSERVATIONS OF NONTHERMAL RADIO EMISSION FROM EARLY TYPE STARS D.C. Abbott, J.H. Bieging and E. Churehwell 47 NONRADIAL PULSATION AND MASS LOSS IN EARLY B STARS G. Donald Penrod and Myron A. Smith 53 NARROW ABSORPTION COMPONENTS IN Be STAR WINDS C.A. Grady 57 LIGHT VARIATIONS OF THE B-TYPE STAR HD 160202 Gustav A. Bakos 62 ULTRAVIOLET SPECTRAL MORPHOLOGY OF 0-TYPE STELLAR WINDS Nolan R. Walborn 66 NONTHERMAL RADIO EMISSION AND THE HR DIAGRAM D.M. Gibson 70 X-RAY ACTIVITY IN PRE-MAIN SEQUENCE STARS Eric D. Feigelson 75 ACTIVE PHENOMENA IN THE PRE-MAIN SEQUENCE STAR AB AUR F. Praderie, T. Simon, A.M. Boesgaard, F. Felenbok, C. Catala, J. Czarny and A. Talavera 81 CORONAL TEMPERATURES J.H. Swank 86 BIPOLAR EJECTION OF MATTER FROM HOT STARS Paris Pismis 91 iii , [ .... STELLAR WINDS: OBSERVATIONAL EVIDENCE FOR A HOT-COOL STAR CONNECTION Wayne L. Waldron 95 SESSION II. - THEORY CONCERNING THE ORIGIN AND DISTRIBUTION OF NONRADIATIVE HEATING/MOMENTUM IN STARS HEATING IN THE SOLAR MANTLE Claudio Chiuderi (Invited Review_ I01 THEORY TESTED BY MEANS OF THE STARS L. Golub (Invited review) 106 THE SCALING OF CORONAL MODELS FROM ONE STAR TO ANOTHER R. Hammer 121 OVERHEATED OPEN CORONAL REGIONS R. Hammer 125 CO-ROTATING INTERACTION REGIONS IN STELLAR WINDS: AND NON-THERMAL RADIO EMISSION IN HOT STARS D.J. Mullan 130 SYNCHROTRON EMISSION FROM CHAOTIC STELLAR WINDS Richard L. White 136 WINDS FROM ROTATING, MAGNETIC, HOT STARS David B. Friend 142 DEPARTURES FROM LTE POPULATIONS VS. ANOMALOUS ABUNDANCES; THE EFFECTS OF HEATING Anne B. Underhill 148 IS THE RATIO OBSERVED X-RAY LUMINOSITY TO BOLOMETRIC LUMINOSITY IN EARLY-TYPE STARS REALLY A CONSTANT? Wayne L. Waldron 159 NON-RADIATIVE ENERGY FROM DIFFERENTIAL ROTATION IN HOT STARS Kwing L. Chan, H.G. Mayr and I. Harris 164 BIPOLAR FLOWS AND X-RAY EMISSION FROM YOUNG STELLAR OBJECTS Yutaka Uchida and K. Shibata 169 NON-RADIATIVE HEATING AND ENHANCED MASS-LOSS DUE TO SHEAR TURBULENCE IN MASSIVE HOT STARS S.R. Sreenlvasan and W.J.F. Wilson 177 A LEAKY WAVEGUIDE MODEL FOR MHD WAVE DRIVEN WINDS FROM CORONAL HOLES Joseph M. Davila 183 iv SECTION III. - THE PROBLEMS OF STARS OF SPECTRAL TYPE B AND EARLIER RADIATIVELY DRIVEN WINDS AND WHAT THEY IMPLY: A REVIEW OF RADIATIVELY DRIVEN INSTABILITIES AND THEIR IMPORTANCE IN HOT STARS A.G. Hearn (Invited review) 188 MAGNETIC EFFECTS IN THE HEATING AND MODIFICATION OF FLOWS IN THE OUTER STELLAR ATMOSPHERES WITH APPLICATION TO EARLY TYPE STARS Yutaka Uehlda (Invited review) 199 EFFECT OF SCATTERING ON INSTABILITIES IN LINE-DRIVEN STELLAR WINDS S.P. Owockl and G.B. Ryblckl 221 NEW INSTABILITIES IN LINE DRIVEN WINDS P.C.H. Martens 226 RADIATIVE AMPLIFICATION OF ACOUSTIC WAVES IN HOT STARS B.E. Wolf 233 ON THE ROLE PLAYED BY LINES IN RADIATIVELY DRIVEN STELLAR WINDS DEPENDING ON THE POSITION OF THE STARS IN THE HR DIAGRAM Marie Christine Migozzl and Jean-Pierre J. Lafon 236 MULTI-LINE TRANSFER AND THE DYNAMICS OF STELLAR WINDS David C. Abbott.and L.B. Lucy 241 SUMMARY OF THE ORIGIN OF NONRADIATIVE HEATING/MOMENTUM IN HOT STARS Anne B. Underhill 243 v ORGANIZING COMMITTEE T. R. Gull NASA Goddard Space Flight Center A G Hearn Astronomical Institute, Utrecht J. A. lonson NASA Goddard Space Flight Center S. D. Jordan NASA Goddard Space Flight Center R. A. McCray Joint Institute for Laboratory Astrophysics A. G. Michalitsianos NASA Goddard Space Flight Center R. W. Noyes Center for Astrophysics, Cambridge, MA G. Traving Institute for Theoretical Astrophysics, Heidelberg Y. Uchida Tokyo Astronomical Observatory A. B. Underhill (chair) NASA Goddard Space Flight Center S. C Wolff Institute for Astronomy, Hawaii H. Zirin Big Bear Solar Observatory, Pasadena, CA vi LIST OF PARTICIPANTS D. C. ABBOTT - Joint Institute for Laboratory Astrophysics, Boulder, CO, USA J. P. CASSINELLI - University of Wisconsin, Madison, WI, USA J. I. CASTOR - Lawrence Livermore National Laboratory, Livermore, CA, USA K. L. CHAN - Applied Research and Systems, Landover, MD, USA C. CHIUDERI - Institute for Astronomy, Florence, Italy J. M. DAVILA - Goddard Space Flight Center, Greenbelt, MD, USA R. P. FAHEY - Goddard Space Flight Center, Greenbelt, MD, USA E. D. FEIGELSON - Pennsylvania StateUnlversity, PA, USA A. W. FULLERTON - David Dunlap Observatory, Richmond Hill, ON, CANADA L. GOLUB - Center for Astrophysics, Cambridge, MA, USA C. GRADY - Space Telescope Science Institute, Baltimore, MD, USA T. R. GULL - Goddard Space Flight Center, Greenbelt, MD, USA R. HAMMER - Institute for Theoretical Astrophysics, Heidelberg, F.R.G. A. G. HEARN - Astronomical Institute, Utrecht, THE NETHERLANDS R. D. HOLT - Swarthmore College, Swarthmore, PA, USA S. D. JORDAN - Goddard Space Flight Center, Greenbelt, MD, USA J.-P. J. LAFON - Observatoire de Paris, Meudon, FRANCE J. L. LINSKY - Joint Institute for Laboratory Astrophysics, Boulder, CO, USA J. M. MARLBOROUGH - University of Western Ontario, London, ON, CANADA P. MARTENS - Astronomical Institute, Utrecht, THE NETHERLANDS A. G. MICHALITSIANOS - Goddard Space Flight Center, Greenbelt, MD, USA D. J. MULLAN - Bartol Research Foundation, Newark, DE, USA S. P. OWOCKI - University of California at San Diego, La Jolla, CA, USA P. PISMIS - Instituto de Astronomia, Mexico, MEXICO F. PRADERIE - Observatoire de Paris, Meudon, FRANCE N. G. ROMAN - Astronomical Data Center, Greenbelt, MD, USA G. B. RYBICKI - Center for Astrophysics, Cambridge, MA, USA M. A. SMITH - National Solar Observatory, Tucson, AZ, USA S. R. SREENIVASAN - University of Calgary, Calgary, AB, CANADA J. H. SWANK - Goddard Space Flight Center, Greenbelt, MD, USA Y. UCHIDA - Tokyo Astronomical Observatory, Tokyo, JAPAN A. B. UNDERHILL - Goddard Space Flight Center, Greenbelt, MD, USA N. R. WALBORN - Space Telescope Science Institute, Baltimore, MD, USA W. L. WALDRON - Applied Research Corporation, Landover, MD, USA D. G. WENTZEL - University of Maryland, College Park, MD, USA R. L. WHITE - Space Telescope Science Institute, Baltimore, MD, USA B. E. WOLF - Institute for Theoretical Astrophysics, Heidelberg, F.R.G J. B. ZIRKER - Sacramento Peak Observatory, Sunspot, NM, USA vii OPENING REMARKS Anne B. Underhill NASA Goddard Space Flight Center Laboratory for Astronomy and Solar Physics This colloquium/workshop has been sponsored by the National Aeronautics and Space Administration and by the American Astronomical Society. We shall now begin three days of what I hope will prove to be invigorating talks and discussion. Today we will refresh our memories about the evidence for the deposition of non-radiative energy and momentum in stellar atmospheres. A useful question to ask is how much nonradiative energy and momentum is deposited in the atmospheres of different stars. Tomorrow we will review what has been established already by theory about the action of possible sources of nonradiative energy and momentum in the atmospheres of different stars. What are the possible sources of the additional energy and momentum deduced to be present in stellar atmosphere? What facilitates the transfer of energy and momentum from the source to the plasma? On Thursday we shall concentrate on the early-type stars and try to clarify our conception of what is going on. It is important to do this, particularly for stars having spectral types earlier than about B2 because it turns out that the empirically selected classification criteria for such spectral types are to a great extent influenced by the amount of nonradiative energy deposited in the atmosphere. Traditionally, one considers a spectral type to be uniquely determined by the radiation field, that is by Tef f. We can no longer assume this, however. We have had three forced cancellations which I am sure you will regret as much as I do: (I) Lawrence Aller has to go into hospital and therefore cannot be with us. Perhaps some of you would like to join in sending a "Get-Well" card to him; (2) Sidney Wolff, because of her obligations at Hawaii and at Kitt Peak cannot now join us, and (3) NASA has detailed Jim lonson to work in downtown Washington for the next three months. We shall miss all of these people; each contributed much to organizing this conference. Let us get to work. EVIDENCE FOR NON-RADIATIVE ACTIVITY IN HOT STARS J. P. Cassinelli Washburn Observatory, University of Wisconsin INTRODUCTION Early-type stars are extremely luminous and the stars don't have outer-convection zones that carry a significant fraction of the luminosity. As a result, stellar wind theorists have focused on radiation processes that are surely occuring in the outer atmospheres, such as radiative acceleration and radiative heating. At this meeting we are being asked to consider departures from the radiative model. The departures can be discovered in several ways. First, from a theoretical perspective we can push the radiative theory to its limits, including all processes likely to couple gas flow with the outward flow of radiation (Castor et al.
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