for young scientists and PhD students

5-11 July 2021

National Astronomical Observatory, Rozhen, Bulgaria
Organized by the Branch “Cosmos” of the Union of Physicists in Bulgaria
under the auspices of the Ministry of Economy of the Republic of Bulgaria

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Astrophysics and Cosmology

Online lecturer: Stoytcho Yazadjiev (Sofia University, Bulgaria)

My lecture is devoted to the gravitational waves. I will  introduce the basics of the gravitational wave science  using concepts from introductory physics. Drawing upon standard physics courses  I will try to explain the principal features of LIGO’s discoveries and make order of magnitude estimates of key parameters of the first gravitational wave event GW150914 by inspection of the observational data.

Online lecturer: Daniela Doneva (University of Tübingen, Germany)

Online lecture: Neutron stars and black holes as a test of physics in its extremes

Observational astrophysics, both in the electromagnetic and gravitational wave channel, are advancing very fast allowing us to probe various aspects of modern physics, such as the behavior of matter at extreme densities and strong gravity. Ideal testbeds for these purposes are the neutron stars and black holes. In our talk we will review the basics behind the theory and observations of these objects. We will focus on some of the most recent efforts on the observational front, such as LIGO/Virgo, NICER, Event Horizon Telescope, etc. and discuss the constraints they impose.

Sun and space weather

Online lecturer and mentor: Manuela Temmer (Institute of Physics, University of Graz, Austria)

On-site assistant: Rositsa Miteva (IANAO – BAS, Bulgaria)

Online lecture: Sun and space weather

Lecturer: Manuela Temmer 

Space Weather is an important issue of global matter. Eruptive flare events, leading to coronal mass ejections (CMEs) and solar energetic particles may damage satellites, enhance radiation doses in the Earth’s atmosphere, or even cause power outages at the Earth’s surface. Today many international groups perform research and develop Space Weather forecasting services based on the knowledge of the physical processes underlying these Space Weather phenomena. However, we are far from understanding all these processes. When does an active region erupt, how is its magnetic connectivity to Earth, how fast do high speed stream structures emerge from coronal holes, where is the magnetic open flux located, and how do CMEs interact with the solar wind and influence their propagation behavior?

This overview talk covers and discusses our recent understanding of the physical processes about the initiation and propagation of CMEs, SEPs, evolution of solar wind structures, their impact at Earth’s atmospheric layers and the caveats in reliably forecasting Space Weather. 

Practical session (on site)

On-site assistant: Rositsa Miteva 

Test your skills on forecasting CMEs:
Use the NASA STEREO-cat tool to derive the 3D geometry for a CME of your choice (select one from CDAW database – which time range is valid for using STEREO data?) and its kinematics up to 20Rs from the Sun. Feed the DBEM CME propagation tool with the derived parameter values and calculate the transit time and impact speed of the CME at Earth.
Use OMNI data and plot plasma and magnetic field solar wind in-situ data. Check whether the CME event actually hit Earth (cross-check with the list from Richardson & Cane). If yes, define the CME structure from the data, and give start and end time of the disturbance, as well as start and end time of the magnetic ejecta region. Compare your model results with real measurements.
Based on the results answer the following questions:
● Is the transit time/speed correct? How large are the uncertainties?
● What does DBEM forecast – shock-sheath or magnetic CME structure? How fast was the solar wind in which the CME was propagating in?
● Can you lower the uncertainties in the forecast and come closer to the real measurements by changing some of the model parameters? In which range you might change parameters to stay within physically meaningful limits?
● Add plots and describe your results

Scientific instruments and payload

Online lecturer: Oliver Roberts (USRA Science and Technology Institute, USA)

In this lecture course, we will take a trip through space and time to learn about the fascinating objects in the high-energy sky, and the instrumentation that is needed to unlock their secrets. Specifically, this course will present what has been achieved in the past and presently, with X-ray and gamma-ray instrumentation, such as grazing incidence mirrors and scintillators. We progress to the future of instrumentation for Astrophysics based on current mission requirements, and the outlook for the next several decades of research in this field.

Astrophotography Practice

Nikola Antonov

Introduction into Astrophotography – Practice

The seminar will be held in the open air in combination with live practice, in which students will participate with questions and tasks related to the process of preparation, photographing, and subsequent processing of the collected material.

Introduction to Astrophotography, 21:00 – 22:30 h. Preparation.

Astrophotography in the Digital Era: Why do we take pictures? How is the shooting of astronomical objects different from normal photography? What is the shooting process and what are its main stages? Can astrophotography have a scientific application?

Main components of a typical astrophotography setup (mounts, telescopes, cameras, software).

Basic concepts and principles of collecting light from celestial objects.

Preparation. With the participation of students!

Preparation begins minutes before sunset. Calibration frames – “Why?” and  “How?”.

Leveling and Polar alignment of the equatorial mount.

Balancing the telescope and how important it is.

Focusing. How to achieve perfect focus using a Bahtinov mask.

Let’s stop the sky! What is automatic guiding and how is it done? Guiding calibration.

On the hunt for photons! The actual astrophotography session starts at 10:30 p.m.

Collecting material from a selected astronomical object.