THERMAL AND IONIZATION ASPECTS OF FLOWS
FROM HOT STARS:
OBSERVATIONS AND THEORY

FIRST ANNOUNCEMENT

SCOPE OF THE WORKSHOP:
Thermal and ionization aspects of flows from hot stars have been rarely discussed at the conferences and symposia about stellar winds. Yet it is crucial for understanding the mechanisms and processes in the winds of hot stars. Moreover the thermal and ionization structure of winds provides the diagnostic methods for the study of the winds by means of optical and UV spectroscopy, X-rays, IR- and radio fluxes.

During the last years an increasing numbers of X-ray observations and high resolution and high S/N optical spectra and UV spectra by HST have been obtained. In the near future the FUSE observations of spectra between 900 and 1200 Å will provide a wealth of new information about the ionziation of winds from hot stars. At the same time there has been a significant progress in numerical modelling of shocked winds and in the theory of colliding winds. Therefore it is time to have a workshop to discuss the present status, the expected progress, and the problems of the observations and theory of thermal and ionization structure of flows from hot stars.

SCIENTIFIC PROGRAM AND CONTRIBUTIONS:
The scientific program is divided into three sessions.

The SOC has invited review speakers. There will be ample time for oral contributions, short contributions, poster sessions and discussion. The scientific sessions will be held on August 23, 24, 26 and 27. Wednesday (Aug. 25) is reserved for an excursion.

We can accept about 70 participants. The participants are expected to present an oral contribution or a poster. The selection will be made by the SOC. The SOC accepts proposals for oral presentations (20 minutes) and for short oral contributions (10 minutes) or posters.

The proceedings will be published in the ASP-Conference Series (editors H.J.G.L.M. Lamers and A. Sapar).

REGISTRATION AND FINANCIAL ASSISTANCE:
The registration fee is USD 100. - before July 15 and USD 125. - later.
For review speakers and SOC members the registration fee is USD 50. - before July 15 and USD 75. - later.
The registration fee is waived for SOC members who give reviews. We have limited funds for financial support (waiving the registration fee) of the astronomers coming from the CIS countries (former S.U.: Russia, Ukraine, ...) and for the students.

The registration fee includes:

The registration fee for accompanying persons is 25 USD.

The registration fee is asked to be paid before 15 July 1999 to the bank account No. 221005105886 of the Hansabank in Estonia (Hansabank's Swift Code is HABA EE 2X). Please don't forget to add (in comments) your name and the word - Workshop.

Cheques payable to Tartu Observatory are also accepted. These must be sent to:

NB! Credit cards can not be used for direct payment of registration fee.

Registration form is available here.

ACCOMMODATION:
The participants are recommended to make early reservations for the hotels because August is the tourist season and some other scientific meetings are foreseen to be held at Tartu at the same time. The LOC can make for you the reservation in the hotel on your choice. Below you will find information about some suitable hotels in Tartu. The prices of hotels may change by about 10 per cent due to possible change of USD/EEK exchange rate (EEK - Estonian crown). Exchange rate is: 1 DM = 8 EEK, 1 USD ~13.5 EEK (Estonian crown is fixed in relation to German marks). The price of the hotels includes a breakfast. The most expensive hotels are located in the centre of town (conference hall is situated close to the centre of town). Prices for single rooms are about 50-70 USD in the centre of town hotels and about 35-40 USD in suburb hotels (about 4-5 km from the centre of town). Prices for double rooms are about 60-85 USD (30-42.5 USD for the bed in the shared room) in the centre of town hotels and 35-50 USD (17.5-25 USD for the bed in the shared room) in suburb hotels. There is a frequent local bus-transportation between the suburbs and the centre (price of a single ticket is about 0.5 USD).

VISA:
A visa is not needed for the citizens (holders of passport) of the following countries:

Visa is not needed starting from March of 1999 for citizens of ``Schengen'' states:
The citizens (holders of passport) of other countries need a visa for coming to Estonia.

All participants of the Workshop who need a visa for coming to Estonia are asked to contact their travel agencies for advice about the application time and procedure. Note that the holders of passports of the following countries can obtain a visa on the border and at the airport of Tallinn (cost ~70 USD): Canada, Israel, South Africa.

TRAVEL:
You can reach Tartu by different ways. For coming to Tartu from western Europe and American countries you need to go through Tallinn (the capital of Estonia) because Tartu has no international airport. From Tallinn you can come to Tartu by bus (about 180 km). The autobus terminal is located about 2 km from the airport. Bus ticket costs about 80-90 EEK (about 6-7 USD). Money can be exchanged both in the airport and in the bus terminals (taxes are lower in the airport terminal than in the bus terminal!). It is possible to rent a car from Tallinn airport. You can reach Tallinn also by ship (ferry) from Helsinki or from Stockholm. Tartu can be reached by train from Eastern Europe, CIS countries and from Latvia and Lithuania.

Tallinn has direct flight connections between the following towns:

More travel information will be given in the Second Announcement.

CLIMATE:
The weather in the Tartu region is usually fine in the end of August (dry and moderately warm - 15÷23 Celsius degrees) but in some years it has been raining strongly in August, for example last year.

IMPORTANT DEADLINES:
July 1, 1999: Registration Forms and Abstracts of scientific contributions.
July 15, 1999: Payment of Registration Fee.

REGISTRATION FORM:
NB! The title(s) and abstract(s) of your proposed scientific contribution(s) must be sent to the SOC and to the LOC. The deadline for abstracts is July 1, 1999.

NB! Registration form must be sent to the LOC till July 1, 1999.
NB! Registration fee must be transferred to Tartu Observatory before July 15, 1999.

Registration form is available here. Please fill it.

ABSTRACT:
Please send the abstract before July 1st by e-mail to:

with a copy to:

Please use LaTeX and include:

Last updated: February 9, 1999
wshop@aai.ee