Bulgarian Astronomer Tanyu Bonev: ISON Comet Could Provide Spectacular Display

Interview |Author: Nikola Petrov | January 23, 2013, Wednesday // 12:35|  views

Bulgaria's Rozhen observatory, the largest in Southeast Europe, survived 2012 despite the drastic budget cuts imposed by the country's centrist-right GERB government. In an inclusive interview for Novinite.com (Sofia News Agency) and Novinite.bg,  Rozhen director Tanyo Bonev reveals fascinating details about the observatory's work.

The Rozhen National Astronomy Observatory was in danger of closing in 2012 over the drastic budget cuts imposed by the government. Are you optimistic about the observatory's survival in 2013?

Yes, I am optimistic. The draft budget of the Institute of Astronomy and the National Astronomy Observatory looks better than it did last year and I hope that the General Assembly of the Bulgarian Academy of Sciences will vote on it within a couple of weeks. Apart from that, we are constantly seeking project financing opportunities in order to aid our budget.  We have prepared an investment project for increasing the energy efficiency of the observatory's buildings that will decrease our energy expenses drastically.

The observatory was "rescued" that it would work on two Bulgarian ministries' projects. That includes research of the potential correlation between space weather and the condition of certain plants. What do expect to find out?

The project you mentioned is called "Study of the effect of solar activity and climate changes on the population and quality of tree species." Within the framework of this project, experts from the Institute of Astronomy and the National Astronomy Observatory will analyze probes gathered from various tree species. Needless to say, trees will not be cut down just for the needs of this project. Probes will be taken from old trees cut down during planned fellings. The surface of the probes will be scanned and the resulting images will be analyzed. In this analysis we will use methods used in the processing of astronomical images, as well as methods used in dendrochronology and dendroclimatology. We will be looking for specifics that could be explained with the effects of global warming. We will carry out a comparative analysis of the results for different regions of the country. Of course, as it is usually in science, unexpected results will be the most interesting.

It seems as if there are more stories in the media about the observatory's financial hardships that its scientific work and the discoveries in which it takes part. Would you name the most important discoveries that Rozhen contributed towards in 2012?

I would rather talk about achievements, since people mean different things by saying "discovery." The observatory's scientific achievements are numerous and they have been published in international professional astronomy journals. A total of 112 articles by Bulgarian astronomers were published in 2012. 34 of them were published in the journals with the highest impact factor for astronomy.

Here are several interesting examples of such achievements:

Among the researched objects were the so called blazars, active galactic nuclei, most of whose radiation comes from a plasma jet that emerges from the supermassive black hole in the center. The existence of this plasma jet explains the quick changes of these objects' radiance. Four articles with results analyzing these rapid changes were published this year. The results are for a couple of blazars that were observed simultaneously by the telescopes of the National Astronomy Observatory in Rozhen, the Astronomy Observatory in Belogradchik, observatories in Italy, the US and India, as well as a radio telescope in Germany and space stations in the roentgen and gamma spectrum.

Another achievement is the very recently discovered star in the initial stage of its evolution. The data received by the Rozhen observatory's telescopes show a high variability of the star, which enables us to determine its physical characteristics, the qualities of the ring surrounding it and the matter that has been falling on the ring from the star.

The observations of the 2012 QGH2 asteroid that is potentially dangerous for the Earth are also very promising. They were carried out in September within the framework of a NASA-coordinated program for the observation of dangerous asteroids. With data received by Rozhen, the asteroid was a carbon-rich object, like (101955) 1999 RQ36. In 2016, NASA will launch a spacecraft to (101955) 1999 RQ36 that will return samples to Earth.  With these data, Rozhen continues to take part in the network for surveillance of objects dangerous for the Earth – a field that the observatory has been traditionally involved in.

Another achievement was made during the observation of the binary star AE Aquarii. This so called "cataclysmic binary star system" consists of a magnetic white dwarf with a mass of 0.63 solar masses and a red dwarf with a mass of 0.37 solar masses. In star systems like this there is matter transferred from the red dwarf (donor) towards the white dwarf (accretor). Interacting with the magnetic field of the white dwarf, the plasma streamer is being fragmented into separate spherically symmetrical blobs ("fireballs"), whose evolution determines the photometric variability of this system. The analysis of the observations made by all telescopes in Rozhen and Belogradchik showed that a separate blob is a fireball that has a mass equal to one ten-millionth of the Earth's mass and that expands for approximately 300 seconds without changing its temperature, reaching a size comparable to that of the planet Jupiter (10 times the size of the Earth), at its maximum luminosity.

You may find more about Rozhen's achievements and its telescopes' interesting observational data at http://www.nao-rozhen.org/news/fr.htm

What will be the focus of your work in 2013 – and what do you expect to discover?

We will continue working in our priority fields, which include the objects in the solar system and the sun itself, the various types of stars and star systems, the remote galaxies and the Universe. In many cases, astronomical discoveries are the result of carefully planned observations: that is why the observation time of our telescopes has been divided between scientific projects selected by competition.

In 2013 we will continue observing exotic binary stars, stars of abnormal chemical composition, variable galaxies. We will search for exoplanets and we will trace the behavior of several comets. Our observations will probably lead to something new and surprising in each of these tasks. The analysis of these new data will lead to the expected discoveries or achievements, but if I were able to name them in advance, they would not be called discoveries.

At the end of this year, the comet ISON will come within less than 2 million km from the Sun. Some have predicted that it will be incredibly bright and spectacular, while others are afraid that it would be a disappointment. How do you reckon?

Indeed, on November 28 this year the comet ISON (C/2012 S1) within less than 2 million km from the Sun. Too little is known for this comet for us to make certain predictions. Some comets fall apart in such close encounters. Depending on their structure and chemical content they either fall apart as a result of tidal forces or evaporate. But the disintegration of comets also takes place far away from the Sun and it cannot be predicted. There are lots of examples of such comets; I will mention only one that was registered with Rozhen's two-meter telescope. That was the comet C/1999 S4 (LINEAR) which I observed with a young colleague of mine back in 2000. Back then, at the end of July, the comet literally disappeared before our eyes for six consecutive days, even though it was almost 120 km away from the Sun. So much information was gathered from these observations that a graduation project, several articles and a number of presentations at national and international conferences followed as a result. If the comet ISON does not disintegrate before its closest pass to the Sun, we may witness something really spectacular in the sky in November.

You may find more details about this comet and other interesting astronomic events in 2013 in the Astronomy Calendar 2013, published by the Institute of Astronomy and the National Astronomy Observatory. You may find information about the calendar at http://nao-rozhen.org/astrocalendar/index.htm

This interview in Bulgarian

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Tags: exoplanets, solar system, tanyu bonev, Rozhen, national astronomy observatory, binary stars, ison, comet, budget cuts, observatory


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