Stan Owocki

There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.
-- Hamlet, Act 1, Scene 5
This accidental double-exposure reveals my true inner spirit! One picture is of me and my daughter, Sarah, eating lunch at a conference in Canada in June 1996. The next winter Sarah and my wife visited London's Madame Tusseau Wax Musuem, where they inadvertently used the same film roll to take a picture of the wax figure of Einstein, with his famous E=mc 2 rendered on the wall.

Basic Information

I am a professor in the Department of Physics and Astronomy at the University of Delaware, and also a member of the Department's Bartol Research Institute. I'm happily married, since 1982, to Suzanne Hatfield Owocki, and we have three adult children, Kevin, Sarah , and David.

I received my Sc.B. in Bio physics from Brown University in 1973, and my Ph.D. in Astrophysics from the University of Colorado in 1982, with a graduate assistantship at the High Altitude Observatory of the National Center for Atmospheric Research . My initial graduate studies began with a year in the Astronony Department at the Ohio State University

I'm a member of the American Astronomical Society (AAS), and the International Astronomical Union (IAU). I  have served on IAU commisson #36 for Stellar Atmospheres, and since August 2000 on the "Organizing Committee" for the IAU "Working Group for Massive Stars". In September 2006, I was elected chair of this OC.   From 2003-2006, I served as OC Chair for the IAU Working Group for Active B-Stars". For more information on these fields of study, check out the Massive-Star Newsletter and the Be Star Newsletter .  

  • My Curriculum vita in PDF .

  • Links to my scientific work

    Research Publications

  • Preprints , of submitted but not-yet-published journal papers, and Reprints , of review articles & conference proceeding papers.
  • Published papers , via links provided by ADS abstract service .
  • Instruction and Collaboration

  • From 1992 to1996, I supervised UDel. Ph.D. graduate student, Steven Cranmer . Find out about his thesis research on Hot-Star Winds , as well as various astronomy-related WWW links.
  • I work closely with David Cohen , focusing on the origin of X-ray emission from early-type stars, under support of a 5-year grant from the NASA Long-Term-Space-Astrophysics (LTSA ) program. From 1998-2000, David was a Bartol Research Scientist, but in September 2000 he moved to an assistant professor position in the Department and Physics and Astronomy at nearby Swarthmore College .
  • I also continue close collaboration with Ken Gayley , who worked with me as a Bartol Research Scientist from fall of 1993 till summer of 1997, when he moved to take a professor position in the Department of Physics and Astronomy at the University of Iowa .
  • From 2003-2008 Bartol Research Scientist,   Rich Townsend (also affiliated with  University College London ) worked with me on various topics related to disk formation in Be and Bp  stars. He is now an assistant professor at University of Wisconsin.
  • From 1999-2002, I  supervised thesis research from University of Delaware Physics PhD. Asif ud-Doula. Check out his thesis on  The Effect of Magnetic Fields and Field-Aligned Rotation on Line-Driven Hot-Star Winds (25MB) [Here is smaller version (0.5 MB) without figures]. From 2005-2008, Asif returned to work in our group as a post-doc. He is now an assistant professor at Penn State - Scranton.

  • I am currently supervising Ph. D. thesis research of two UDel Physics graduate students, Chris Russel & Mary Oksala.
  •  I have ongoing collaborations with numerous other colleagues around the world, including:
  • Joachim Puls of the Universitaet Sternwarte Muenchen
  • Mark Runacres of the Royal Observatory of Belgium.
  • Achim Feldmeier of University of Potsdam
  • Luc Dessart, now in Marseilles
  • Nir Shaviv  of the Rahcah Institute of Physics, Hebrew University,  Jerusalem, Israel
  • Outreach and General Reviews

  • For the Encyclopedia of Astronomy and Astrophysics , I wrote a general-astronomy-level review article on Radiatively Driven Stellar Winds from Hot Stars , which can be accessed as either a PDF (290Kb), postscript (404Kb), or gzipped ps (125Kb) file.
  • Several of our research projects on hot-star winds were featured in a general-level summary article, Winds that Sail on Starlight , that appeared in the Spring 1997 issue of the the San Diego Supercomputer Center (SDSC) magazine, Gather/Scatter
  • The spring 1999 Centennial meeting of the American Physical Society included an invited poster session highlighting Great Discoveries in Astronomy . For this I prepared a poster featuring Solar and Stellar Winds . I've also created a slide-show version of this. Using Microsoft's free PowerPoint viewer , you can also browse either the poster source file (~1.3Mb) or the slide-show source file (~1.3Mb).
  • For this APS poster there is now a version with the text translated into french by Dr. Roland Grappin of the Observatoire de Paris-Meudon , in Meudon, France.
  • Every three years each IAU commission is asked to prepare a report on progress in its field. These are compiled with other commission contributions in the triennial IAU Reports on Astronomy . As a member of IAU Commission #36 for Stellar Atmospheres, my own contribution toward this includes a 2-page summary for the period 1996-9 of " Recent Advances in Studies of Stellar Mass Loss " , which is also available as a TeX , gzipped Postscript , or PDF document.
  • You can also access copies of my 1993-6 periodic report in TeX , gzipped P ostscript , or PDF formats.
  • I am a member of the IAU "Organizing Comittee" (OC) for the "Massive Star Working Group". Among other activities, this group publishes the Massive-Star Newsletter .
  • I am also currently (until Aug. 2006) serving as chair of the OC for the IAU Working Group on Active B-Stars . For information of these stars, check out the Be Star Newsletter .
  • Finally, here is an incomplete and rather outdated overview of our Hot Star Wind Astrophysics research program at Bartol. I still hope to update this, someday...
  • Talks/Seminars/Presentations

    (The original presentations can be browsed using Microsoft's free PowerPoint viewer ; but in many cases I also provide a Portable Data Format (PDF) version which can be viewed using the free Adobe Acrobat Reader )

  • "Radiatively Driven Winds and Aspherical Mass Loss ", an invited paper presented at a conference on the "Fate of the Most Massive Stars" held in Jackson Hole, Wyoming in May 2004.  ppt or pdf format.

  • In October 2003, at a school on "Stellar Winds and Mass Loss" held in Oleron, France, I was invited to give a series of 4 x 1.5 hour lectures on "Stellar Wind Mechanisms and Instabilities".  A brief description of the lectures, with links to PDF files of the lecture slides is as follows:
  •  lec1-sw.pdf   (6.9 MB) "Overview + Solar Wind": A general overview of wind equations and formalism, with then a summary of the gas-pressure driven outflow of the solar wind that results from solar coronal heating.
  •  lec2-hswcak.pdf  (5 MB)  "CAK  Line-DrivenWinds from Hot-Stars": A simplified review of the basic Castor, Abbott, and Klein (1975; CAK) theory for line-driven mass loss in hot-stars, but emphasizing the physically more transparent  `Qbar' notation.first introduced by Ken Gayley (1996, ApJ).
  • lec3-hswrot.pdf  (8 MB) "Rotation and other Multi-D Effects in Hot-Star Winds":Extension of line-driven wind theory for hot-stars to account for the vector nature of the line-force, with particular application to cases with rapid rotation. This lecture emphasis the peculiar properties of the vector line-force, and summarizes many of the points made in the general colloquium I give on 'Winds that Sail on Starlight'. It also concludes with a brief summary of my ideas for rotational mass ejection to make Be-star disks, a topic also covered elsewhere in my collouquium on 'The Launching of Be Star Disks'.
  • lec4a-csw.pdf (1.9 MB) "Wave-Pressure Models of Cool-Star Winds": Summarizes the little I know about cool-star mass loss, briefly reviewing attempts to explain this through Alfven-wave-pressure driven winds, and also emphasizing the general `Fine-tuning problem' of obtaining a large mass loss rate with a terminal speed that is significantly smaller than the surface escape speed.
  • lec4b-sedd.pdf  (0.8 MB) "Continuum-Driven Winds from Super-Eddington Stars": Summarizes recent ideas about continuum-driven winds based on instabilities that could occur when a star approaches and exceeds the Eddingoton limit.
  • lec4c-ldi.pdf  (5.9 MB) "Line-Deshadowing Instability": Reviews the basis of the strong, intrinsic instabilites that can lead to extensive small-scale structure in line-driven stellar winds.
  • "MHD Simulations of Line-Driven Winds from Hot Stars ", a poster paper presented with my graduate student, Asif ud-Doula, at the AAS meeting in Washington DC Jan. 2002. Also available in PDF format , as a PowerPoint show , and as aJPEG file. There is also a reprint of this work in gzipped postscript or pdf format.
  • "Winds that Sail on Starlight ", a general colloquium presented at Space Telescope Science Institute (STScI) on 11/07/01; available in PDF format , as a PowerPoint show , and even as RealPlayer video of the actual talk. This is latest version of a similar talk I've given at several institutions, including at Penn State University (2/01.), Harvard-Smithsonian Center for Astrophysics (6/01), and Univ. de Montreal (9/01).
  • " The Rocket Science of Launching Stellar Disks " a general colloquium presented at several institutions, including U. of Del (4/00), Johns Hopkins U. (5/ 00), and Swarthmore College (9/01). Here is PDF version of the talk , and here is html slide show of talk.
  • " (Possible) Links Between Pulsation and Line-Driven Mass Loss in Massive Stars ", an invited introductory review presented at the IAU Colloquium #185 on Radial and Nonradial Pulsations as Probes of Stellar Physics , held in Leuven, Belgium from July 26-31, 2001. Here is a PDF version of the talk . Here is a digital picture gallery of photos taken during the conference. Here is link to proceedings write-up for the talk, in PDF or gzipped PostScript  
  • " Interacting Stellar Winds: Theoretical Overview ", an invited introductory review presented at the workshop on ` held July 2000 on Isle-de-la-Magdelene, Quebec, Canada. Here is a PDF version of the talk. There is also a reprint of the proceedings write-up of this talk, in PDF or gzipped PostScript . Finally, here is a digital picture gallery of photos taken during the conference and its associated bike-trips.
  • " The Outer Evolution of Wind Structure ", contributed talk at the Tartu (Estonia) workshop on " Thermal and Ionization Apects of Flows from Hot Stars ", August 1999. (There is also  a reprint of the proceedings write-up of this talk, in PDF or gzipped-postscript .)
  • " Effect of Clumping on Wind-Compressed-Disk Inhibition ", contributed talk presented at IAU Colloquium #175 on " The Be Phenonemon in Early-Type stars ", July 1999. (There is also  a reprint of the proceedings write-up of this talk, in PDF or gzipped-postscript .)
  • " Radiatively Driven Winds and Disks ", a summary overview of my research program presented to our instiute's annual `visiting committee'.
  • " The Peculiar Physics of Line-Driving ", seminar presented at the University of Pittsburgh, March 1999.
  • "Solar and Stellar Winds ", a 36"x36" single page, Powerpoint source file of Invited Poster presented at the " Great Discoveries in Astronomy " session of the Centennial meeting of the American Physical Society , April 1999. This is also available as a multi-page slide-show in Powerpoint , or its HTML export. As noted above, there is now a version with the text translated into french by Dr. Roland Grappin of the Observatoire de Paris-Meudon .
  • Exploratory slides on various research topics in progress

  • Effect of inner disk radius on Be star emission profile
  • A Radiatively Driven Orbital Mass Ejection ( RDOME ) scenario for production of Be star disks. The basic ideas for this are contained the above-noted Powerpoint presentation on "The Rocket Science of Launching Stellar Disks ", for which I've also exported an html version .

  • GO BACK to the Bartol Research Institute Home Page, or the U.Del. Dept. of Physics and Astronomy Home Page, or to the Bartol VAX Cluster.

    Numerical Simulation of a Wind Compressed Disk for hot-stars with equatorial rotations speeds ranging from 200 km/s (left) to 450 km/s (right).

    Digital photos from various scientific conferences, etc. Other personal links

    Questions? Send them to .

    Page last updated: Oct. 09,  2012