FIRST ANNOUNCEMENT:
Active OB-Stars: Laboratories for
Stellar & Circumstellar Physics
August 29 - September 2, 2005
Sapporo, Japan
Stanislav Stefl
European Southern Observatory
Casilla 19001
Santiago 19, Chile
email:
sstefl@eso.org
Received: November 17, 2004
Dear Colleagues,
We cordinally invite you to an international conference entitled
Active OB-stars: Laboratories for Stellar & Circumstellar Physics
to be held at Hokkai-Gakuen University, Sapporo, Japan, for August 29
- September 2, 2005.
The purpose of this first announcement is to supply some general
information about the conference, and to encourage all interested
colleagues to visit the conference website at
http://www.kwasan.kyoto-u.ac.jp/be2005/
to make a preliminary registration for the conference.
Scientific Motivation
Extensive monitoring from both ground-based and orbiting observatories
has provided several lines of evidence that many hot, luminous, OB-type
stars, and their accompanying mass outflows, are highly structured and
variable on a range of spatial and temporal scales.
A central theme of this meeting is to utilize these active OB-stars
as laboratories for studying the underlying physical processes for
such activity -- magnetic fields, pulsation, rotation, radiative
instabilities, binarity -- with focus on implications for the
structure and evolution of the central star, as well as any associated
circumstellar envelope, disk, and mass outflow.
Such a broad range of physical processes mandates consideration of
several specific observational classes of Active OB-stars,
including classical Be stars, magnetic Bp stars,
 Cephei stars, slowly-pulsating
B (SPB) stars, Be X-ray binaries, and B[e] stars.
The meeting will build upon substantial recent advances in both
observational and theoretical modeling of structure and activity in
these stars, augmented by new and emerging observational techniques
and by ever-increasing computer power. Some key examples include: a
unified interpretation of the complex variations in photospheric lines
of Be and other active stars in terms of non-radial pulsations; direct
detection of stellar magnetic field in several non-chemically peculiar
hot stars; the renewed possibility of Be-star rotation being close to
critical; applications of interferometric techniques to resolve not
only circumstellar disks but also central stars; and availability of
massive numerical simulations to model radiative, electromagnetic and
gas dynamical interactions in these stars.
To guide and constrain development of physical models, a general theme
is to exploit several new and emerging observational techniques and
facilities, including both space- and ground-based spectra over
wavebands ranging from the infrared to X-ray, with also a special
emphasis on taking advantage of recent advances in interferometric
techniques for direct spatial resolution of both central stars and
their circumstellar emission.
Some of the key issues to be discussed are:
- What mechanism(s) are responsible for driving material from
the stellar surface and the oft-observed reappearance and
disappearance of circumstellar emission over times scales ranging
from months to years?
- Under what circumstances is the material propelled directly
into an outflowing wind, extended over a broad "cloud'' or
confined in a thin disk?
- Are the processes feeding circumstellar material impulsive or
steady?
- In the case of Be stars, how close is the stellar rotation to
the critical rate?
- Is the development of a disk one common phase in the evolution
of rapidly rotating stars, or is it an evolutionary branch?
- Is rapid rotation an intrinsic consequence of massive star
evolution, or might it sometimes depend on external factors like
cluster membership, metallicity, or an earlier phase of close
binary mass exchange?
- How does binarity influence the ejection and evolution of
circumstellar and/or disk material?
To exchange various ideas and enhance the interaction between
participants, a thematic discussion session will take place at the end
of each half day.
Although thematically focused on Active OB-Stars, the phenomena and
processes being examined -- disks, radiatively driven mass loss,
non-radial pulsation, rapid rotation, magnetic activity -- are, in
various combinations, also of central importance to a wide range of
astrophysical systems. In particular, the rapid and perhaps even
near-critical rotation of Be stars provides a well-observed prototype
for studying the effects of rapid rotation on stellar mass loss. For
example, the combination of a centrifugally ejected equatorial disk
and strong radiatively driven polar wind -- which is a key developing
paradigm for many classical Be stars -- might likewise represent a
potential model for the observed form of mass ejection from Luminous
Blue Variables like  Carina. Such
considerations reflect an emerging perspective that Be stars could
represent a manifestation of the rotational 
limit inferred in evolutionary models of massive stars. This embodies
another specific example within the broad meeting theme to explore
Active OB-Stars as laboratories for stellar and circumstellar
physics.
Scientific Organization
Each session will be composed of invited reviews, contributed oral
presentations and posters. The number of invited reviews is small, so
as to offer an important space to as many as contributed talks and
discussion sessions. Posters will be at display during the entire
conference and there will be ample time for poster viewing during
breaks.
The selection of oral presentations among the proposed contributions
will be made on the basis of the abstract, so as to serve at best the
aim of the conference.
Preliminary Programme
- Active OB-stars: past, present and future
- Overview of Active OB-Stars - Stan Owocki
- Statistical inference of Be star periodicity - Anne-Marie Hubert
- Dynamical processes
- Coupling of rotation and pulsation in OB stars - Umin Lee
- B-field measurements of OB stars - Coralie Neiner
- Dynamical tides of close binaries - Bart Willems
- Stellar mass loss as origin of circumstellar material
- Links between photospheric activity and formation of
circumstellar structures of Be stars - Thomas Rivinius
- Radiatively driven winds of OB stars - Jiri Krticka
- Structure and dynamics of circumstellar disks
- Polarimetric observations of the circumstellar matter and their
interpretation - Karen Bjorkman
- Interferometric measurements of fast rotating OB stars and
circumstellar disks - Olivier Chesneau
- Theory vs. observation of circumstellar disks and their
formation - John Porter
- Evolutionary effects in active OB-stars
- The role of multiplicity (to be confirmed)
- Rotational evolution of massive stars - Georges Meynet
- Activity of OB stars and their evolution (to be confirmed)
Dedication
The meeting will be dedicated to the work of Prof. Mike Marlborough
(University of Western Ontario, Canada), Prof. Ryuko Hirata
(Kyoto University, Japan) and Dr. Anne-Marie Hubert (Observatoire de Paris-Meudon,
France). They all have been pioneers of the physical modeling of
mass-loss and circumstellar disks of Be stars as well as of their
observational studies for several decades. By 2005, these well-known
scientists will have recently (or will soon be) retired, and it will
be a suitable moment for the international scientific community to
recognize their extensive contributions.
Important Dates
- 25 November, 2004: First announcement which includes the basic
information.
- 1 March, 2005: Second announcement which includes call for papers and
information on registration and hotel reservation.
- 30 April, 2005: Deadline for grant applications and abstract
submission for oral presentations. Also deadline for abstract
submission by those applying for grants.
- 30 June, 2005: Deadline for registration, hotel reservation,
and abstract submission for poster presentations.
- 1 July, 2005: Third announcement, including the programme.
- 15 August, 2005: Final announcement.
- 28 August, 2005: Welcome reception.
- 29 August - 2 September, 2005: Conference.
Location and Transportation
Sapporo, a city of 1.8 million people, is the capital of Japan's northernmost
island. Due to the unusual combination of its large size with its rich
natural environment, Sapporo has been ranked by nation-wide surveys as
one of the most desirable places to live. Conveniently situated close
to Sapporo, New Chitose Airport has frequent domestic flights to/from
the main international airports at Narita, Haneda, and Kansai, as well as
regular direct flights to several cities overseas. For more information
about Hokkaido and the city of Sapporo, please visit the official pages of
Hokkaido and
Sapporo.
The conference will be held at Hokkai-Gakuen University, Sapporo.
Directions to the university from New Chitose Airport and from
downtown Sapporo will be available in the second announcement.
Registration Fee
The registration fee for participants is 15,000 Japanese Yen (JPY) (an
equivalent of about 140 USD) if paid before 30 June, 2005. After that
date, it will increase to 18,000 JPY (an equivalent of about 170
USD). The fee includes coffee breaks and refreshments, Internet
facilities during the meeting, and a copy of the proceedings. The
social events, conference dinner, conference trip and the program for
accompanying persons are not included.
The registration fee for accompanying persons is 2,000 JPY (an
equivalent of about 20 USD). It includes coffee breaks and
refreshments and Internet facilities during the meeting.
More detailed information will be announced later.
Accommodation
There are many hotels with a range of prices within walking distance
or within a distance of five minutes by subway from the conference venue.
The following are estimates of hotel rates per person per night including
breakfast in Sapporo available to the participants:
| Category |
| Single room |
| Double room |
| | | [JPY/USD] |
| [JPY/USD] |
| Luxury Hotels | | 15000/140 |
| 14000/130 |
| Economy Hotels | | 8000/70 |
| 8000/70 |
| Youth Hotels | | |
| 4700/43 |
Detailed information on hotel registration will be announced later.
Financial Support
The LOC plans financial support for a limited number of participants.
The policy will be included in the second announcement.
Proceedings
The proceedings of the conference will be published in the ASP
Conference Series, for which the editors will be S. Stefl (chief
editor), S. Owocki and A Okazaki. Each registered participant will
receive a free copy of the proceedings. The guidelines for contributions
will be announced later.
Scientific Organizing Committee
- Conny Aerts (Belgium),
- Dietrich Baade (Germany),
- Jon Bjorkman (USA),
- Mike Marlborough (Canada),
- Ignacio Negueruela (Spain),
- Atsuo Okazaki (Japan),
- Stan Owocki (USA, Co-Chair),
- Philippe Stee (France),
- Stanislav Stefl (Chile, Co-Chair),
- Richard Townsend (USA)
Local Organizing Committee
- Ryuko Hirata (Kyoto Univeristy),
- Toshihiro Horaguchi (National Science Museum),
- Eiji Kambe (National Defense Academy),
- Umin Lee (Tohoku Univeristy),
- Daisaku Nogami (Kyoto University),
- Akemi Okazaki (Secretary),
- Atsuo Okazaki (Hokkai-Gakuen University, Chair),
- Hideyuki Saio (Tohoku Univeristy)
Contact Address
E-mail: be-loc@kwasan.kyoto-u.ac.jp
or
Atsuo Okazaki
Hokkai-Gakuen University
Sapporo 062-8605, Japan
Email: okazaki@elsa.hokkai-s-u.ac.jp
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