-----------------------------------------------------------------------
                         First Announcement

               Hot Subdwarf Stars and Related Objects
                23 - 27 July 2007, Bamberg, Germany

           Contact: subdwarf3@sternwarte.uni-erlangen.de
-----------------------------------------------------------------------

A series of biennial workshops on hot subdwarf stars commenced in 2003.
The aim of these workshops is to disseminate recent results on the properties,
formation, and evolution of hot subdwarf stars and related objects, and to
assess the impact of these results on other areas of astrophysics. The first
workshop was held in Keele, UK, and the second in Santa Cruz de La Palma,
Spain.  The third meeting is organized by the Dr. Remeis-Sternwarte and the
University of Erlangen-Nuernberg and will be held in Bamberg, Germany from
July 23 - 27, 2007.

Topics to be discussed will include:

   * Modeling the formation and evolution of hot subdwarf stars 
   * Hot subdwarfs and the ultraviolet-upturn phenomenon
     in elliptical galaxies
   * Hot subdwarfs and hot horizontal-branch stars in the field,
     clusters and galaxies
   * Hot subdwarfs in binary systems
   * Atmospheric properties of hot subdwarfs
   * Asteroseismology of hot subdwarf stars
   * Progenitors and progeny of hot subdwarf stars
   * Surveys & kinematics

IMPORTANT: Further details including a webpage, call for papers,
registration fees, accommodation, deadlines, etc. will be communicated in
a second announcement in early 2007. To ensure you receive this announcement
and to remain on our mailing list, please reply to this email, or send a
mail to

             subdwarf3@sternwarte.uni-erlangen.de

Please pass on this announcement to any of your colleagues who you think would
like to attend the workshop but who may have been missed from this mailing
list.


Scientific background
---------------------

Hot subdwarf stars are extreme horizontal branch (EHB) stars and pre-white
dwarf stars.  The EHB stars are core helium-burning stars with extremely
thin hydrogen envelopes, and form the majority of bright stars in surveys
for extremely blue objects, where they are classified as subdwarf-B (sdB)
stars.  They also appear in the colour-magnitude diagrams of some globular
clusters as an extension of the blue tail formed by classical horizontal
branch (HB) stars, though it is not clear why some clusters show this
feature and others do not.  The pre-white dwarf stars are related to the
sdBs, but have exhausted their capacity to burn helium in the core.  Many
of the brightest hot subdwarfs in the field are of this class, and they
are classified as sdO stars. Evidence is growing that most luminous sdO
stars are related to chemically peculiar post-AGB stars.

Hot subdwarf stars and their relatives are believed to be important
contributors to the hitherto mysterious UV upturn phenomenon in early-type
galaxies; and a comprehensive investigation on this issue is being
performed by the Galaxy Evolution Explorer (GALEX).  The formation of EHB
stars remains, in general, a matter of debate.  Recent results for
Galactic EHB stars show that the majority are close binary stars, so mass
transfer and mass loss due to interactions between the stars clearly play
a role.  EHB stars are an excellent tool for studying evolution in close
binary stars. 

Some EHB stars show p-mode pulsations with periods of a few
minutes and some others show g-mode pulsations with periods on the order
of hours.  Asteroseismology can be used to measure fundamental parameters
for these stars directly.  Hot subdwarf stars are also a laboratory for
studying the effects of diffusion, weak stellar winds, radiative
levitation and gravitational settling.  These processes are seen to affect
the peculiar composition of their atmospheres and also play a role in the
driving mechanism for pulsations and, perhaps, the subsequent evolution of
the star.

Studies of the space motions of hot subdwarfs is scarces but has already let to
the discovery of so-called hyper-velocity star, unbound to the galaxy.


Scientific Organising Committee
-------------------------------

Stephane Charpinet, Toulouse (France)
Betsy Green, Tucson (USA)
Uli Heber, Bamberg (Germany) chair
Simon Jeffery, Armagh (UK)
Sabine Moehler, ESO Garching (Germany)
Ralf Napiwotzki, Hatfield (UK)
Roy Ostensen, Leuven (Belgium)
Philipp Podsiadlowski, Oxford (UK)
Francois Wesemael, Montreal (Canada)
Sukyoung Yi, Yonsei (Korea)


Local Organising Committee:
---------------------------

Edith Day
Horst Drechsel (chair)
Markus Firnstein
Stephan Geier
Uli Heber
Heiko Hirsch
Stefan Nesslinger
Norbert Przybilla
Florian Schiller
Rainer Sterzer
Alfred Tillich

   on behalf of the Local Organising Committee,

   Uli Heber & Horst Drechsel