Weekly seminars 2019/2020
Our weekly seminars take place on Thursdays at 12:30 in AMU Astronomical Observatory building at 36 Słoneczna Street. The person responsible for organization of seminars is Dr Tomasz Kwiatkowski, to whom all questions regarding dates/subjects, as well as the video equipment needed should be directed.
Talks in years: 2017/2018, 2016/2017
27th February 2020
5th March 2020
dr Edyta Podlewska-Gaca (IOA)
Thanks to adaptive optics imaging we are able to obtain high resolution images of asteroids and get new insight into their nature. I will present the results of such studies on VLT/SPHERE telescope. In particular it will be described how Hygiea became a candidate for a dwarf planet, and why Pallas looks like a golf ball.
12th March 2020
dr Dagmara Oszkiewicz (IOA)
19th March 2020
prof. Tadeusz Michałowski (IOA)
26th March 2020
mgr Dorota Krużyńska, mgr inż. Mikołaj Krużyński (IAO)
2nd April 2020
prof. Edwin Wnuk (IOA)
9th April 2020
16th April 2020
23th April 2020
dr Anna Marciniak (IOA)
30th April 2020
mgr Magda Butkiewicz-Bąk (IOA)
7th May 2020
prof. Sławomir Breiter (IOA)
14th May 2020
mgr Ewa Śreniawska (IOA)
21st May 2020
dr Przemysław Bartczak (IOA)
28th May 2020
prof. Wojciech Dimitrow (IOA)
4th June 2020
mgr Julia Matysiak (IOA)
Previous talks in 2019/2020:
30th January 2020
dr Radosław Poleski (OA UW)
Full understanding of planet formation and evolution cannot be achieved without finding exoplanetary analogs of planets observed in Solar System. In particular, analogs of Uranus and Neptune are hard to find due to their long periods and low luminosities. The origin of Uranus and Neptune cannot be explained using standard models of planet formation and ice giant exoplanets can shed light on formation of the widest-orbit planets. I will present currently known ice giant exoplanets and their connection to widely-discussed free-floating planets. I will also discuss possible future studies with NASA and ESA flagship missions: WFIRST and Euclid.
23th January 2020
prof. Agnieszka Kryszczyńska (IOA)
(60558) Echeclus was discovered in 2000 by Marsden and classied as a Centaur object. Surprisingly it presented several ourbursts: the largest ever observed for Centaurs in December 2005, and the smaller ones in May 2011 and in August 2016. On the pre-discovery archive images a cometary activity was also visible — that is why this object got also a cometary designation: 174P/Echeclus.
Lightcurves obtained between the outbursts did not show any cometary activity even during perihelion passage in April 2015, so they may serve as an input data for spin vector and shape modelling. For this purpose photometric data should cover different observing geometries. Collecting them for Echeclus is a long-lasting process because its long orbital period.
Combining all available lightcurves covering a 20 year observing period with three new lightcurves obtained in December 2019 at our RBT robotic telescope in Arizona, allowed us to determine the spin axis and shape model for this object. For that we used the SAGE technique developed by P. Bartczak from our Institute. Our model seems to be the first one obtained for a centaur based on only photomteric data.
9th January 2020
prof. Piotr A. Dybczyński (IOA)
Our computer codes and stellar data sets allowed us to search for a potential source of the interstellar comet 2I/Borisov among nearby stars. The double star Kruger 60 seemed to be the best candidate but radial velocity data were lacking. This possibility was ruled out by the new radial velocity of the Kruger 60 center of mas obtained form private communications. We will describe methods of such an investigation and the limitations in making results publicly available.
More details: https://arxiv.org/abs/1909.10952
19th December 2019
mgr Paweł Koleńczuk (IOA)
Near Earth Asteroid photometry is struggling with the problem of their observed high velocity in the sky during approaching Earth what causes image stretching of asteroid and/or stars on CCD frame (they leave trails). In such case typical differential photometry with circular apertures does not give good results. The solution is a pill aperture that perfectly reflects the shape of the trails. As a result, we save optimum signal-to-noise ratio. The shape of this aperture can be described as two half-circles connected by a rectangle. The use of the pill aperture is not limited to asteroid photometry. The problem of the observed high velocity in the sky also applies to artificial Earth satellites. Pill aperture can also eliminate the problem of star photometry during unexpected movement of the telescope e.g. during a
sudden gust of wind.
12th December 2019
mgr Karolina Dziadura (IOA)
The “Eclipse de Sol Chile 2019” project was an expedition to Chile to observe the total solar eclipse. The expedition was attended by students and Ph.D. students from Adam Mickiewicz University in Poznań, University of the Arts Poznań and the Nicolaus Copernicus University in Toruń. The total solar eclipse could be observed in Chile on July 2, 2019. For observations, we chose the mountain on the Pacific coast in the region of La Higuera (29.4544° S, 71.2472° W, 795 m a.s.l.). At this location, the total solar eclipse lasted 2 minutes 35.8 seconds. The first contact of the Sun with the Moon occurred at 19:22: 53.6 UT. The beginning, maximum and end of the total eclipse phase were 20: 38: 24.0 UT, 20: 39: 42.1 UT and 20: 40: 59.8 UT respectively. The sun was then at an altitude of 13.6° and azimuth 306.8°. For registration we used: Canon 6D camera with a 100-400 mm telephoto lens (photographs), Canon 650D camera with a 150 mm lens (film), Nikon D90 camera with a 200 mm lens (photographs), Canon 700D camera with 800 mm lens (photographs). We recorded the Sun trajectory using a meteorological device called a heliograph.
5th December 2019
mgr Monika Kamińska (IOA)
Optical observations of objects in low Earth orbits
28th November 2019
prof. David Vokrouhlický (Astronomical Institute of Charles University, Prague)
Traditionally, long-period comets (LPC) are defined by their huge orbital periods: 200 yr at minimum, but many have effective orbital periods as long as millions of years. At the first sight, they are mysterious visitors to the inner Solar system on incomparably elongated orbits from its extreme outskirts. Yet, their population may be well understood using advances in our knowledge of the Solar system early evolution and a flood of new and accurate orbital data. I shall describe an evolutionary model for the LPCs that reasonably well matches their orbital architecture. Admittedly, it is less successful in describing their observed flux to the inner Solar system, though I shall discuss plausible reasons for this mismatch. The model allows to make predictions which could be tested by LSST observations within the next decade.
21th November 2019
dr Arkadiusz Hypki (IOA)
Project gaia@home (former GAVIP-GridComputing) is an ESA project run by Poznan Astronomical Observatory staff which will add additional features to the Gaia archive by incorporating CPU power of volunteers’ computers of the BOINC grid (best known of its SETI@Home project).
gaia@home eventually will allow to define a series of jobs which will be able to read entire Gaia archive and compute some CPU intensive jobs on the BOINC platform (best known from SET@home project). The users, in order to use the GAVIP-GC software will provide source code to deal with their scientific problem. Everything else (e.g. reading data from Gaia, communicating with BOINC, downloading the results) will be done by gaia@home software.
During the seminar I will present the current status of the project.
14th November 2019
dr hab. Anna Bartkiewicz (UMK Toruń)
High angular resolution studies of the 6.7 GHz methanol maser emission provide one of the best existing tools for deriving 3D kinematics around high-mass proto- or young stars. Regions that are hidden in the dense environments and are not easily reachable at other wavelength ranges. Particularly, multi-epoch, sensitive observations using the very long baseline interferometry networks are successfully used to investigate proper motions of single maser clouds in high-mass star forming regions.
I will present recent studies of sources that showed ring-like structures at the 6.7 GHz line and were discovered in the Torun survey with the 32-m radio telescope. Using the European VLBI Network over 10 years and obtaining images of emission with miliarcsecond angular resolution, we can follow detailed kinematics (tangential velocities of order a few km/s) of masing clouds in the vicinity (ca. 1000 au) from central stars. Unexpectedly, masers are expanding from the centres of the ring, indicating a physical relation to an outflow or an expanding bubble rather than a disc.
7th November 2019
dr Krzysztof Kamiński (IOA)
In September/October 2019, four domes and telescopes were installed in Chalin. We present the assembly of a new satellite observation system PST3. The basic stages of system construction will be discussed. Photo coverage from the construction process will be presented. Basic parameters, technical details of five telescopes and other equipment will be discussed. System capabilities, further construction plans and test images from some telescopes will be presented.
24th October 2019
dr Magdalena Otulakowska-Hypka (IOA)
Optical interferometry is a method of astronomical observations that gathers light collected by several telescopes observing the same object simultaneously. It allows to measure sizes and even exact shapes of astronomical objects. We use optical interferometry to examine a large number of symbioticstars. Our observations and analysis will allow not only to determine the size of the stars, but thanks to reaching their innermost regions, we will be able to observe directly the extension of the red giant’s surface due to tidal forces. I will present the first results of this project.
17th October 2019
dr John Williamson (University of Glasgow)
A new theory of light and matter incorporates a complex scalar field, responsible for the mutual confinement of light and rest mass in “elementary” particles. This field parallels many of the observed properties of dark matter and dark energy. These include the gravitational effects, the property of the observed increase in the rate of “expansion” of the universe, the transparency of the substance to light and the non-observation of dark matter to date. This invisibility does not mean that the substance is immune to experiment. Experimentally observable effects of this field in the nearby solar system, the local galactic cluster and the wider universe will be discussed. As well as the usual properties associated with dark matter/energy such as gravitational lensing, the observed expansion of the universe and galactic rotation, the talk will discuss, among other things, solar coronal heating, high energy particle generation (x and gamma rays and high-energy charged particles), and matter-antimatter asymmetry in the physical universe.
John Williamson worked at CERN for 7 years, in nano engineering in Philips for 5 years, and as an associate professor in the College of Science and Engineering in Glasgow University for 27 years. He is currently the director of Quicycle an international group devoted to the advancement of science. He has published widely in the fields of experimental physics, nano-engineering, and in theoretical physics. He has (co-) authored over a hundred papers. He has over twelve thousand citations in peer-reviewed papers and an h-index of 45.
10th October 2019
mgr Rita Wysoczańska (IOA)
Since 1950 when Oort published his paper on the origin of comets a continuous search for the stars which were able to perturb cometary motion has been conducted. The aim of this presentation is to discuss two cases in which the data obtained from observations were used and stellar perturbations (of different intensity) on cometary motion were detected. Our results show how different the dynamical evolution of comets would have looked when their motion was considered only in the Galactic gravitational potential. Uncertainties both in stellar and cometary data were carefully taken into account. Our analysis indicates that the occurrence of stellar perturbations on cometary motions is very rare and the uncertainties of these effects are hard to estimate.
Previous talks in 2018/2019:
6th June 2019
mgr Emil Wilawer (IOA)
At the beginning of XXI century astronomy entered the Big Data era, in which robotic telescopes produce petabytes of data. Most of them consist of CCD images which require automatic measurements by the specialized photometric pipelines. In our Institute we still use a traditional method of aperture photometry which requires frequent manual intervention. While beeing well tested, this approach starts showing its weekness when faced with the increasing inflow of observing data. It also lacks photometric callibration which recently became a routine procedure in differential photometry thanks to the sky surveys (SDSS, PanSTARSS) which released their high accuracy photometric measurements of millions of stars. In the talk I will present the use of the photometric pipeline of Michael Mommert for the automatic photometry of asteroids and briefly describe main stages of the computations The application of this procedure for derivation of asteroid phase curves will also be shown.
30th May 2019
mgr Piotr Guzik (OA UJ)
Discovered last year, the first recognized interstellar visitor in Solar System, 1I/2017 U1 (Oumuamua) is the long-sought link between our own Solar System and systems around other stars, heralding an onset of a new field in astronomy. Our group has played an important role in the effort of characterizing this unique body. We were awarded 12 hr of DDT on the Gemini North 8.1-m telescope. As a result, we obtained the highest quality photometric and spectroscopic data, which have revealed some remarkable and unexpected properties. I will review the current state of knowledge on Oumuamua, discuss the impact of this body on science and society, and speculate on possible future avenues.
In the second part of my talk, I will present our first dedicated search for dust trails of asteroids, that forms along the asteroids orbit as a result of their disruptions. The trail can be observed for many years, as showed by the studies of two recently disrupted asteroids, P/2010 A2 and P/2012 F5. We argue that a dedicated survey with a large telescope can possibly detect much fainter (thus older) trails – precious remnants from historical disruptions – thereby providing basis for detailed research into the causes of the disruption. A pilot survey was conducted by our team at SALT. We have successfully detected the known ultra-faint trail of the disrupted asteroid P/2012 F5 – proving the concept in terms of technical feasibility. I will present the main science goals of the survey, discuss the results from the pilot phase, and draw conclusions for the full phase which has been recently initiated.
23th May 2019
mgr Jacek Haponiak (IOA)
“Colmbo top” model describes rotational dynamics of a rigid body moving around the material point under the efect of gravitational interaction. It can be applied to the analysis of Earth’s Moon rotation, Solar System planets, exoplanets, moons, asteroids and space debris. During presentation “Colombo top” model, its aplications and analitical solution will be shown.
16th May 2019
prof. Tomasz Kwiatkowski (IOA)
Working under a contract to ESA we are preparing a web-based Service for Archival NEO Orbital and Rotational Data Analysis (SANORDA). It includes a NEO Period Determination Tool (NPDT) which takes asteroid lightcurves from a database and uses them to derive their rotation periods. The algorithm is based on a well known Fourier series analysis and implemented as a python program called PerFit. In the talk I will present a typical use cases of the NPDT service, which is currently in a beta stage. Using PerFit I will also show how the uncertainties in the asteroid lightcurves influence the accuracy with which their synodic periods can be derived.
25th April 2019
mgr Volodymyr Troiansky (IOA)
Basaltic V-type asteroids and their fragments are collisional remnants of planetesimals that existed 4 billion years ago. Their distribution, physical and dynamical properties provide important constrains on processes such as planetary differentiation, planet formation and evolution of planetary systems.
Asteroids with the prograde sense of rotation, located in the inner Main Belt, that have semi-major axes of their orbits smaller than that of Vesta, are less likely to have migrated from Vesta due to thermal forces dragging them outwards (the Yarkovsky effect).
Assuming that the inner Main Belt is populated only by the Vesta like objects, around 81% of asteroids in the so-called scattered resonances region are expected to have retrograde sense of rotation. Similarly 40% of objects in the low inclination region, should have retrograde rotation. Substantial surplus of asteroids that have prograde rotation could indicate that also other planetesimals (different from Vesta) contributed to this population. Those predictions are verifiable via photometric studies in which asteroid lightcurves are used to derive senses of rotation.
4th April 2019
prof. Piotr Dybczyński (IOA)
Almost 60 papers were published on the first macroscopic body coming from an interstellar space. Both ground-based and space-born most powerful telescopes observed it for many hours. Unfortunately such a short visit caused substantial lack of knowledge on its nature and as a result we have more questions than answers. It appeared even a suggestion that it is an alien spacecraft, rather ruled out by the majority of the astronomic community. Anyway, strange and mysterious name: ‘Oumuamua fits very well in this case.
28th March 2019
mgr Patrycja Bagińska (IOA)
I want to present a study of disk instabilities in black hole binaries in which X-ray novae outbursts were observed. Soft X-ray transients (SXTs) are the subclass of accreting low-mass X-ray binaries (LMXB) and they spend most of their lifetime in quiescent state. Those objects an be discovered only during outburst phase when they become one of the brightest sources in the X-ray sky. Almost all of SXTs are recurrent sources. It was noticed that intervals between outbursts may vary from tens of days to decades or maybe even longer, as only a few systems have shown two or more outbursts. Usually we observe outbursts of the regular, symmetric shape or so called fast rise exponential decay (FRED) shape which is typical for X-ray novae outburst. I will present numerical simulations of instability process that occurs in X-ray novae sources. I’ve calculated models which predict time dependent evolution of ionization instability in an accretion disk around black hole, assuming viscosity parameter to be proportional to the total pressure. As a result of modelling I get confirmation that the ionization instability in the examined sources is responsible for occurrence of characteristic X-ray novae outbursts. This study shows how analysis depends on assumed global accretion disk parameters and chemical abundances.
21th March 2019
mgr Mikołaj Krużyński (IOA)
Satellite catalog contains orbits of about 20000 objects. Maintenance of up-to-date catalog requires systematic observations of all objects. To obtain necesarry data a high precision measurements of satellite positioning and precise timing are required. An appropriate process of observation and reduction is required, as well as specialized software.
Although observations of satellite objects have been carried out for over 60 years, the use of telescopes in the case of cataloging objects moving below 2000 km above the Earth’s surface is a novelty. The technological development that has taken place over the last decade allowed for high quality astrometric observations of satellites in LEO orbits (Low Earth Orbit).
Observations of LEO objects were performed using the RBT telescope over the past few years. We are able to analyse these observations and determine orbits. Currently we want to have possibility to use other type observations. In this talk I will present preliminary results of combining laser ranging and astrometric observations used in the orbit determination problem.
14th March 2019
dr hab. Michał Michałowski (IOA)
I will present the results of observations (including those with RBT/PST2) of a gamma-ray burst (GRB) 171205A and the associated supernova (SN) 2017iuk, which led to the discovery of a hot gas cocoon. This was possible because observations started very early and the jet emission was weak. This gives support to the theoretical models of GRB/SN explosions, which predicted the existence of such a cocoon. This discovery opens the possibility to study internal processes during explosions of very massive stars, and hence will shed light on the understanding of the production of heavy elements. In case you miss this seminar, I will also give it at the Faculty of Physics on 3rd of April:
24th January 2019
prof. Mirosław Giersz (CAMK PAN)
I will very briefly describe the basic ideas behind the Monte Carlo MOCCA code and discuss the set-up of the MOCCA Survey Database project – a database containing thousands of Monte Carlo (MOCCA) simulations of real globular clusters. Afterwards, I will list and shortly describe projects connected with the analysis of the Database from the point of view of compact objects. Projects which deal, among others, with: BH and NS populations in star clusters and their interactions, BH Subsystems and IMBHs and their observational signatures, and many more. Finally, I will discuss recent developments of the MOCCA code and planed simulations for the MOCCA Survey Database II.
17th January 2019
mgr Krystian Iłkiewicz (CAMK PAN)
Cataclysmic variables (CVs) are interacting binary stars that consists of a degenerate white dwarf accreting mass from a normal star donor. Our understanding of evolution of such systems have been challenged by properties of their known population, such as white dwarf mass distribution, orbital period distribution and their space density. With the recent developments of population synthesis codes we are able to reproduce the CV population characteristics. However, there are still unsolved problems posed by the population of classical novae among the CVs, such as for example why there is only one system known to have both dwarf nova and classical nova outbursts. In my talk I will discuss the recent developments of population synthesis codes as well as my work on understanding of classical novae population using population synthesis.
10th January 2019 (two shorter talks)
mgr Aleksandra Leśniewska (IOA)
Binary stars are very important topic of astrophysical research. Using the data from photometric and spectroscopic observations, we are able to determine much more physical parameters of the system’s components than in the study of a single star. We obtain information not only about effective temperatures, metallicity, rotation velocity, but what is the most important, masses and radii of two components. Compact binaries become crucial when considering the evolution of stars and their influence on the later generations of astronomical objects. The system composed of a white dwarf and a red giant, is called symbiotic star. Researches on these types of objects contribute to a more accurate understanding of the geometry of binary stars and mechanisms in these systems. Our work is dedicated to modeling the physical parameters of the SY Muscae, symbiotic star in the southern sky. Based on photometric and spectroscopic observational data, in the infrared and visible range, using the PHOEBE program we created a model of light curves and radial velocity. This model clearly describes the shape and dimensions of the components of SY Muscae. The result of the analysis is a model of light curves, radial velocity, and a set of SY Muscae physical parameters. Based on the comparison of the results obtained by us with the results in the literature, it turns out that SY Muscae is a typical symbiotic star.
Dust production is a very important issue in galaxy evolution. Unfortunately, we are still unable to determine its formation mechanism. I will present the investigation of dust production in nine galaxies at the redshift at z > 6, for which dust emission has been detected. In recent years, more accurate measurements were made using the most powerful instruments, eg ALMA, which contributed to better estimates of luminosities and sizes, and thus to determine the masses of gas, dust and stars in the studied galaxies. We conclude that asymptotic giant branch (AGB) stars did not contribute to the dust formation significantly in these Early Universe galaxies, and that supernovae are unlikely to produce the bulk of the dust mass. I will discuss how the advent of future large telescopes will contribute to this topic.
21th December 2018 (Optional seminar at 13:30)
dr Anna Kapińska (National Radio Astronomy Observatory, USA)
The new continuum radio surveys delivered in recent years are an outstanding resource in addressing long-standing questions in modern astrophysics. In this talk I will focus on the lowest radio frequencies (<230MHz) currently accessible with the ground based new-generation radio facilities. Specifically, I will present our recent results on radio spectral energy distributions and star formation of Sculptor Group galaxies and Magellanic Clouds, which we observed with the Murchison Widefield Array (MWA) — a low frequency SKA precursor from an Australian outback. Although of low angular resolution, especially as compared to ALMA, these sensitive low frequency observations are very complementary to GHz observations, and necessary for a complete picture of physical processes occurring in galaxies.
20th December 2018
dr Agata Makieła (University of Kent, UK)
In the summer 2017 I was involved in the NASA Frontier Development Lab, an intense 8-week study concentrated on tackling topics important to NASA using machine learning tools. During the programme interdisciplinary teams of early career researchers were looking at issues related to planetary defence, space weather, and space resources. The team I was a part of investigated shape modelling of near-Earth asteroidsfrom radar data. These asteroids are the Earth’s closest neighbours in space, most accessible by space flight and with a potential for causing a threat to the planet. Even though they are constantly monitored, detailed characteristics, like shapes and sizes, are available for only a selected few. Physical models are required to successfully plan spacecraft missions and set up impact mitigation strategies. Additional incentive is in learning know how our space environment works and evolves. Reconstructing asteroid shapes and spins from radar data is, like many inverse problems, a computationally intensive task. Shape modelling also requires extensive human oversight to ensure that computational methods find physically feasible results. In this talk I will discuss the results of our work at NASA Frontier Development Lab 2017, exploring the application of machine learning tools to the shape modelling task.
13th December 2018
dr Krzysztof Hełminiak (CAMK PAN)
In years 2015-2017 we have conducted a programme of high-resolution spectroscopic observations of a sample of detached eclipsing binaries (DEBs) observed by the Kepler satellite in its original mission field. With the 1.88-m telescope of the Okayama Astrophysical Observatory and its HIDES spectrograph, we have collected 290 spectra of 23 systems, in order to analyse them thoroughly and as comprehensively as possible. The sample contains variety of different objects (giants, low-mass stars, multiples, pulsators, planet hosts), many of which were studied for the first time, and with parameters derived very precisely. In my semi-formal talk I will present a subjective selection of 10 systems from our sample that I find the most interesting, intriguing and important for the stellar astrophysics. Kittens will be included.
10th December 2018 (Optional seminar at 16:00)
dr José Ricardo Rizzo Caminos (Centro de Astrobiologia, Madrid)
Opportunities using radio astronomy facilities in Madrid
6th December 2018
dr Arkadiusz Hypki (IOA)
GAVIP-GridComputing (shortly GAVIP-GC) is an ESA project run by Poznan Astronomical Observatory staff which will add additional features to the Gaia archive by incorporating CPU power of volunteers’ computers of the BOINC grid (best known of its SETI@Home project). GAVIP-GC eventually will allow to define a series of jobs which will be able to read entire Gaia archive and compute some CPU intensive jobs on the BOINC platform. The users, in order to use the GAVIP-GC software will have to provide only source code to deal with their scientific problem. Everything else (e.g. reading data from Gaia, communicating with BOINC) will be done by GAVIP-GC software. During the seminar I will present the current status of the project and our plans for the next milestones.
29th November 2018
prof. David Vokrouhlický (Astronomical Institute of Charles University, Prague)
Asteroid families are clusters of small bodies that move about the Sun on fairly similar orbits. They are outcome of a collisional disruption of a common parent asteroid. Therefore, analysis of members in families can bring us interesting information about the fragmentation process at high-energies and, otherwise inaccessible, interior properties of asteroids. The most valuable in this type of studies are young families, in which the evolutionary processes had not enough time to confuse the results. I will review the past two decades of a race to find ever younger families in the main belt, demonstrating also what kind of unexpected results it brought along.
22nd November 2018
prof. Edwin Wnuk (IOA)
15th November 2018
prof. Jerzy Krzesiński (OA UJ)
We are showing that some of the exoplanetary signatures found in the light curves of a couple of sdBV star systems (KIC 5807616 and KIC 10001893) might be of different source than exoplanet light reflection or radiation effects. We point out that at least one signature can be explained by a combination of pulsating frequencies of the host star and others might be just artifacts. Using simulated light curves we also analyzed frequency changes of the signal around 0.256 c/d (~3.9 day) visible in the Fourier transform of the KIC 10449976 sdO star light curve. Our simulations show that it is difficult to reproduce the observed signal frequency variations by the weather changes in the exoplanet atmosphere.
8th November 2018
dr Justyna Gołębiewska (IOA)
From the launch of the first artificial satellite: Sputnik in 1957, more than 5000 launches have placed 8000 satellites into orbit, of which about 4800 remain in space. In addition to operational satellites in orbit there are over 12000 space debris. To to ensure safety in space European Space Agency (ESA) as well as European Commission carries out the Space Situational Awareness (SSA) Programme, consisting of three segments. One of these segments is the Space Surveillance and Tracking (SST) system that comprises detecting,cataloguing and predicting the orbits of objects orbiting the Earth, and related applications. We are showing our results in two of main segment of SST: Re-entry Predictions for Risk Objects and Collision Warning.
25th October 2018
prof. Tadeusz Jopek (IOA)
We have made an extensive search for grouping amongst the near Earth asteroids (NEAs). We used two D- functions and rigorous cluster analysis approach. We have found several new groups (associations) among the NEAs: the objects moving on similar orbits with small minimum orbital intersection distances (MOID) with the Earth trajectory.
18th October 2018
dr Krzysztof Kamiński (IOA)
In recent years European Space Agency (ESA) as well as newly established European Space Surveillance and Tracking Consortium (EU SST) — both of witch Poland is a member state — have increased the effort towards a new satellite tracking system for Europe, that would be independent from external sources of satellite orbital data. Such a system is typically composed of several radar sensors for tracking Low Earth Orbit (LEO) satellites and several optical sensors for higher orbit targets. However recent developments in optical telescopes enabled an efficient tracking of LEO satellites with an equipment 2 to 3 orders of magnitude cheaper than a typical satellite radar. Of course optical satellite sensing suffers from a daytime and bad weather limitations to a much greater extent than a satellite radar. Therefore it is reasonable to simulate an optical satellite tracking network, using a global cloud-fraction statistics, in order to estimate possible outcome from such an entertainment. In this seminar I present preliminary results of simulations showing weather it is possible to build an efficient global optical satellite tracking network, what locations should be selected on Earth, and how many sites should be used in order to have a very high probability of observing each target every day.
11th October 2018
dr hab. Agnieszka Pollo (OA UJ)
I will present recent results from the VIMOS Public Extragalactic Redshift Survey (VIPERS). VIPERS – with its \sim 90,000 spectroscopically measured galaxies, a large volume (5 x 10^7 h^(-3) Mpc^3), and an effective spectroscopic sampling > 40% – can be considered the state-of-the-art counterpart of “local” (z<0.2) cosmological surveys but targetting the epoch at z \sim 1. I will summarize our newest results on the properties of galaxies and large scale structure and their common evolution since z \sim 1. How galaxies changed during the last 8 bln years? What are the properties of the 3D cosmic structure emerging from VIPERS measurements and what they can they tell us about cosmological parameters? And, most interestingly – what remains unknown and why do we need even larger surveys in the future?
4th October 2018
Talks in 2017/2018:
21st June 2018
mgr Grzegorz Dudziński (IOA)
The volume of an asteroid shape model, when combined with the size and mass estimates, is essential in bulk density determination – one of the most important physical parameters that allow us to peek inside asteroids and make conclusions about their inner structure. The shape model uncertainty propagates to volume, and analogously to any
other property determined from the model, affecting every conclusion drawn for a population of small bodies under scrutiny. There definitely exists a compelling need for a procedure of quality and uncertainty assessment of asteroid models. I would like to present modelling-technique-independent uncertainty assessment method based on gen-
erating clones of investigated model. By far, the most abun-dant data type for the most numerous target sample is disc-integrated relative photometry in visual bands and the majority of published asteroid models are based solely on it. For that reason the presented method deals with photometric lightcurves and absolute sparse data.
14th June 2018
dr Milena Ratajczak (IA UWr)
Several aspects of stellar evolution can be tested with B-type stars in eclipsing binary systems. Finding tighter constraints on the value of the convective core overshooting parameter is one of the most valuable among them. Precise photometry and high-resolution spectroscopy with high SNR are required to achieve that goal, but since many of the targets are bright enough, the challenge is fair. The approach to examine the aforementioned aspect of stellar evolution using observations of B-type stars obtained with a wide range of spectrographs, as well as BRITE-Constellation satellites, will be presented.
7th June 2018
dr Magdalena Otulakowska-Hypka (IOA)
The disk instability model attributes the outbursts of dwarf novae to a thermal-viscous instability of their accretion disk, an instability to which nova-like stars are not subject. We aim to test the fundamental prediction of the disk instability model: the separation of cataclysmic variables (CVs) into nova-likes and dwarf novae depending on orbital period and mass transfer rate from the companion. We analyse the lightcurves from a sample of ~130 CVs with a parallax distance in the Gaia DR2 catalogue to derive their average mass transfer rate. The method for converting optical magnitude to mass accretion rate is validated against theoretical lightcurves of dwarf novae. Dwarf novae (resp. nova-likes) are consistently placed in the unstable (resp. stable) region of the orbital period – mass transfer rate plane predicted by the disk instability model. None of the analyzed systems present a challenge to the model. These results are robust against the possible sources of error and bias that we investigated. The disk instability model remains the solid base on which to construct the understanding of accretion processes in cataclysmic variables.
24th May 2018
mgr Przemysław Mróz (OA UW)
Theories of planet formation predict the existence of a population of unbound (free-floating) planets. Gravitational microlensing provides a unique tool for studying these objects. The first results of Sumi et al. (2011) claimed that Jupiter-mass free-floating planets are as common as main-sequence stars. However, these results appear to disagree with censuses of substellar objects in young clusters and star-forming regions and with predictions of planet formation theories. I will present new results of the analysis of a ten times larger sample of microlensing events discovered by the OGLE-IV survey during the years 2010-2015. They shed new light on the population of free-floating planets.
17th May 2018
mgr Ewa Kosturkiewicz (IAO)
Spectroscopic observational campaign of the delta Ceti star in 2014 – 2017 – preliminary results
10th May 2018
mgr Krzysztof Langner (IAO)
Kustaanheimo-Stiefela (KS) transform is used to regularize and linearize Kepler problem and t transform it into harmonic oscillator. Regularization changes the independent variable (time) and can improve accuracy of numerical propagation of orbits, especially when eccentricity is high. Lissajous variables are used as action-angle variables for harmonic oscillator. In my presentation I will show these two transforms using canonical formalism and extension for orbits with explicit time dependent perturbation.
26th April 2018
dr Agnieszka Słowikowska (CA UMK)
In my talk, I will describe the basic concept of polarimetry as well as the most common use of it as a tool in astronomy. I will present a few polarimeters that are in use at the moment. Additionally, I will discuss our recent polarimetry study of white dwarfs and neutron stars.
19th April 2018
prof. Andrzej Niedzielski (CA UMK)
Stars beyond the MS are frequently avoided in planet searches because they are known to exhibit various types of variability: RV variations of unknown origin were pointed out to be common in red giants (RGs) by Walker et al. (1989), and multiple pulsation modes are often present. In addition, the rotation of starspots across the stellar disk can affect the spectral line profiles of these stars (Vogt et al. 1987; Walker et al. 1992; Saar & Donahue 1997). However, soon after the first discovery (ι Dra b Frink et al. 2002), searches for planets around stars beyond the MS have become recognised as important in building a complete picture of planet formation and evolution for several reasons. First, they allow extending the reach of the most versatile RV technique, which is not applicable on the MS because of the high effective temperature of the stars and their fast rotation rates, to objects with masses significantly higher than solar (e.g., o UMa, a 3 M⊙ giant with a planet – Sato et al. 2012). Second, the planetary systems around evolved stars are much older than those around MS stars, and therefore they are suitable for long-term dynamical stability considerations. Planetary systems around giants are also subject to changes induced by stellar evolution, and therefore are suitable for studies of star – planet interactions, and last but not least, evolved planetary systems carry information on the initial population of planetary systems to be found around white dwarfs. It is no surprise then that several projects devoted to searches for RV planets that orbit RGs were launched. One of the largest of them is the PennState – Toruń Centre for Astronomy Planet Search (PTPS, Niedzielski et al. 2007; Niedzielski & Wolszczan 2008a,b).
In my talk I will present the sample of PTPS, current status of our planet search and the most recent discoveries. I will also discuss some properties of the exoplanets around evolved stars from the PTPS perspective.
12nd April 2018
prof. Agata Różańska (CAMK)
X-ray astronomy requires satellites to make progress in searching the distribution of hot matter in the Universe. Approximately 15 years period of time is needed for full construction of the flight instrument from the mission concept up to the launch. A new generation X-ray telescope ATHENA (the Advanced Telescope for High Energy Astrophysics) was approved by European Space Agency as a large mission with a launch foreseen in 2028. I will talk about how ATHENA will help us to study Hot and Energetic Universe, and I will present Polish involvement to the mission development.
5th April 2018
dr Michał Drahus (OA UJ)
Disruptions of asteroids are often viewed as ancient events leading to the
formation of asteroid families and pairs, binary and multiple systems, and
discrete dust bands within the Zodiacal cloud. But thanks to the
remarkable progress in solar system science over the last decade, we can
now directly observe asteroidal disruptions occurring before our eyes.
Various lines of evidence suggest that the disruption can be a consequence
of a rapid rotation resulting from a long-term spin-up, or a result of a
hypervelocity collision with another minor object. Up until recently the
two mechanisms were difficult to distinguish because of the unknown
rotation rates of the disrupting small asteroids, but this has changed
after our team investigated the recently disrupted asteroid P/2012 F5.
Using the Keck II telescope atop Mauna Kea we discovered several fragments
of the object and obtained the highly anticipated measurement of the
rotation rate, which turns out to be the fastest known among active
asteroids and is fast enough to support the rotational disruption
scenario. Further observations with the Hubble Space Telescope have
revealed that the system is in fact the first ultra-young asteroid family
identified to date, and given its likely formation via rotational
disruption, it can also be the first known asteroid family of
22nd March 2018
prof. Agnieszka Kryszczyńska (IAO)
The NEO-DECS web service an open access central service of structured
metadata on NEOs, as well as a platform for collaboration among NEO
researchers, using elements well known in social networking like user
profiles, forum facility, private messaging, etc. Such service shall make
it easy to locate necessary databases and services on NEOs, learn about
forthcoming conferences and workshops, and allow for advertising new
observing programs, telescopes availability, numerical tools, etc.
During the talk I will demonstrate NEO-DECS based on several use cases.
15th March 2018
8th March 2018
prof. Edwin Wnuk (IAO)
In December 2017 Polish Space Agency announced the National Space Programme
(KPK) for Poland. After concultations with all interested parties KPK
shall be accepted in the first quarter of 2018. Next the first calls
shall be announced covering a broad range of space studies, including
astronomical reserach.Quadruple stellar system in the 1:1 resonance
During the talk three highest priority KPK projects shall be presented as
well as the areas in which the first calls for grant proposals shall be
announced. Guidelines for grant applications as well as the planned KPK
budget shall be discussed.
1st March 2018
dr Magdalena Polińska (IOA)
We would like to present results for the two objects, GT UMa B which is a part of multiple system and for the eclipsing binary star BD-00 2862. The spectra for the first object were obtained with the spectrograph ESPERO mounted on the 2-m telescope in Rozhen and for the second one with PST1 (Poznań Spectroscopic Telescope 1) located in Borowiec. For those stars we estimated atmospheric parameters, such as: the effective temperature, surface gravity, metallicity and the projected rotational velocity. The observed spectra were compared with the set of synthetic spectra calculated with the iSpec code.
22nd February 2018
dr Arkadiusz Hypki (IOA)
The amount of data in science which is delivered nowadays increases like never before. It applies for all fields of research. However, physics and astrophysics appear to push the requirements for data storage and analysis to the boundaries. With already existing missions like Gaia and for future projects like LSST the need for reliable and scalable data storage and management is even higher. The amount of data for many projects is too big for simply processing with bash or python scripts. Tools which would allow easy data analysis are crucial in research these days.
BEANS software is a web based, easy to install and maintain, new tool for interactively distributed data analysis. It provides a clear interface for querying, filtering, aggregating, and plotting data from an arbitrary number of datasets and tables.
During the seminar I will present features of the BEANS software and show how it can help scientists to analyze huge datasets.
25th January 2018
Dr An-Li Tsai (IAO)
Galactic molecular outflows affect star formation activities in galaxies. This process is important for galaxies evolution. I will talk about case studies on two nearby starburst galaxies NGC 2146 and NGC 3628.
18th January 2018
Prof. Joanna Mikołajewska (CAMK)
I will present and discuss recovery of the binary underlying the classical nova of 11 March 1437 recorded by Korean royal astronomers whose age is independently confirmed by proper motion-dating. I will also discuss the physical characteristics and the present evolutionary status of the binary system responsible for the nova outburst based on preliminary results of our ongoing extensive observations.
11th January 2018
Prof. Michał Ostrowski (OA UJ)
New gamma-ray observatories: Cherenkov Telescope Array (CTA)
4th January 2018
Dr Dagmara Oszkiewicz (IAO)
SANORDA (Service for Archival NEO Orbital and Rotational Data Analysis) is an ESA funded project aimed at archiving light curve and orbital data. In work package WP1200 we focus on determining historical orbits of all NEOs to reproduce their orbital improvement history starting from discovery onwards. The historical orbits may aid better observation planing and improve our understanding of astrometric biases present in the Minor Planet Centre database. We focus on two orbit computation methods: the ranging method and the traditional linearised least squares method. For asteroids with short observational arcs (shortly after discovery) we use ranging method and when the phase space of possible orbital solutions is sufficiently contained (close to Gaussian distribution) we switch to least squares. Those orbital histories are being reproduced for around 17 000 NEAs, which will result in almost 2 000 000 orbits. The project is ongoing and the final database is expected in 2018.
14th December 2017
Prof. Sławomir Breiter (IAO)
Quadruple stellar system in the 1:1 resonance
7th December 2017
Prof. Piotr Dybczyński (IAO)
On the dynamical history of the recently discovered interstellar object A/2017 U1
30th November 2017
Dr Tomasz Kwiatkowski (IAO)
A new catalogue of asteroid lightcurves
23rd November 2017
Dr Przemysław Bartczak (IAO)
Asteroid models uncertainty
16th November 2017
Prof. David Vokrouhlický (Astronomical Institute of Charles University, Prague)
Origin and evolution of short-period comets
9th November 2017
Dr Krzysztof Kamiński (IAO)
New satellite tracking camera in Poznań
26th October 2017
Dr Michał Michałowski (IAO)
The first observation of radiation from colliding neutron stars – the sources of gravitational waves
19th October 2017
Dr Paweł Kankiewicz (Jan Kochanowski University, Kielce)
Dynamical studies of asteroids in retrograde orbits
12th October 2017
Dr Anna Marciniak (IAO)
The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation
Talks in 2016/2017:
8th June 2017
Mikołaj Krużyński (IAO)
SST observations – not only with PST2
1st June 2017
Dr Toni Santana-Ros (IAO)
A ménage à quatre of European projects linked by the study of asteroids
25th May 2017
Krzysztof Langner (IAO)
New approach to Kustaanheimo-Stiefel transform
18th May 2017
Ewa Kosturkiewicz (IAO)
Study of beta Cephei-type pulsating stars
11th May 2017
Dr Michał Michałowski (IAO)
Dust, galaxies and gamma ray bursts
27th April 2017
Patrycja Bagińska (IAO)
X-ray novae: analysis and modelling of outbursts
20th April 2017
Magda Butkiewicz-Bąk (IAO)
Photometry of asteroids in crowded star fields
6th April 2017
Dr Anna Marciniak (IAO)
Photometric survey, modeling and scaling of long-period and low-amplitude asteroids
30th March 2017
Prof. Tadeusz Jopek (IAO)
The Morasko meteorite chain fall
23rd March 2017
Dr Magdalena Polińska (IAO)
Spectroscopic study of delta Scuti stars
16th March 2017
Prof. Witold Szczuciński (Institute of Geology, Adam Mickiewicz University)
Geological and environmental effects of small hypervelocity meteoroid impacts – insights from Morasko impact
9th March 2017
Łukasz Gruszka (IAO)
Legal Time Distribution System: a technique for transfering accurate time
2nd March 2017
Dr Krzysztof Kamiński (IAO)
Software tools for planning and reduction of astrometric observations of Earth’s Artificial Satellites
23rd February 2017
Dr Przemysław Bartczak, Grzegorz Dudziński (IAO)
Dr Wojciech Dimitrow (IAO)
A report from ESO workshop
26th January 2017
Grzegorz Dudziński (IAO)
SAGE development status; invertion of asteroids’ radar echo observations
12th January 2017
Dr Jerzy Nawrocki (OAG CBK PAN, Borowiec)
Caesium fountain in Borowiec
15th December 2016
Dr Tomasz Kwiatkowski (IAO)
The olivine-dominated composition of the Eureka family of Mars Trojan asteroids
8th December 2016
Dr Krzysztof Kamiński (IAO)
SST observations with PST1 and PST2
24th November 2016
Prof. David Vokrouhlický (Astronomical Institute of Charles University, Prague)
Tilting Saturn during planetary migration
17th November 2016
Dr Jan Janik (Masaryk University, Brno)
Hot stars in Brno
10th November 2016
Filip Berski (IAO)
Close approach of Gliese 710
3rd November 2016
Dr Przemysław Bartczak (IAO)
SAGE: modelling asteroid shapes based on light curves and radar data
27th October 2016
Dr Arkadiusz Hypki (Leiden Observatory)
MOCCA – current state and [Breiter] future ahead
20th October 2016
Dr Dagmara Oszkiewicz (IAO)
Searching for parent bodies of anomalous HEDs
13th October 2016
Dr Magdalena Otulakowska-Hypka (IAO)
Close binary stars
6th October 2016
Michał Żołnowski, Grzegorz Duszanowicz, Marcin Gędek,
Michał Kusiak, Rafał Reszelewski (6ROADS)
SST and NEO observations with 6ROADS telescope network