As part of the AstroGrid-PL project, we have implemented a large scale data management system for... more As part of the AstroGrid-PL project, we have implemented a large scale data management system for the Polish astronomical community within the framework of the PLGrid Plus project, with built-in metadata services, replication and distributed storage based on the well-established iRODS middleware. In parallel, we have implemented the Polish Virtual Observatory, which provides access, search, retrieval and in situ processing for this data using the protocols and standards established by the International Virtual Observatory Alliance (IVOA). These standards are already in use at astronomical facilities across the globe, and implementing them within the framework of AstroGrid-PL and the PLGrid Plus project enables us not only to provide advanced data retrieval services to our users, but also to leverage a large body of existing astronomical data analysis software and give our users access to external data resources provided on the same principles.
The first Global e-Competition on Astronomy and Astrophysics was held on-line in September-Octobe... more The first Global e-Competition on Astronomy and Astrophysics was held on-line in September-October 2020 as a replacement for the International Olympiad on Astronomy and Astrophysics, which was postponed due to the ongoing pandemic caused by COVID-19. Despite the short time available for organisation, the competition was run successfully with 325 students from over 42 countries participating with no major issues. The feedback from the participants was positive and reflects the ways in which such events can boost interest in astronomy and astronomy education. With on-line activities set to be more prevalent in the future, we present an overview of the competition process and some of the lessons learned in hindsight as a guide for other event organisers.
Radial-velocity measurements and sine-curve fits to the orbital radial velocity variations are pr... more Radial-velocity measurements and sine-curve fits to the orbital radial velocity variations are presented for the last eight close binary systems analyzed the same way as
Radial velocity measurements and simple sine-curve Ðts to the orbital velocity variations are pre... more Radial velocity measurements and simple sine-curve Ðts to the orbital velocity variations are presented for the third set of 10 close binary systems : CN And, HV Aqr, AO Cam, YY CrB, FU Dra, RZ Dra, UX Eri, RT LMi, V753 Mon, and OU Ser. All systems except two (CN And and RZ Dra) are contact, double-line spectroscopic binaries, with four of them (YY CrB, FU Dra, V753 Mon, and OU Ser) being the recent discoveries of the Hipparcos satellite project. The most interesting object is V753 Mon with the mass ratio closest to unity among all contact systems (q \ 0.970^0.003) and large total mass [(M 1 Several of the studied systems are prime candidates for combined light and ] M 2 ) sin3 i \ 2.93^0.06]. radial velocity synthesis solutions.
Improvements in detector technology mean that today astronomy, like other experimental sciences, ... more Improvements in detector technology mean that today astronomy, like other experimental sciences, is dominated by the rapid accumulation of extremely large data sets. For example, a typical single night of observations at a telescope equipped with a CCD camera can produce several gigabytes of raw data, while new survey telescopes such as the LSST are projected to produce up to 1 terabyte of data per night. This means that it is no longer possible for a single researcher to store and process the data on their own workstation, and indeed it is not even possible for a single researcher to analyze all the available data contained in even their own observations (which may contain information about hundreds or thousands of additional objects in the same field of view as the target star or galaxy). Thus a new approach to data storage, retrieval and processing is required, which harnesses geographically distributed computing resources to provide storage, processing, and sharing of these larg...
We present preliminary results of optical monitoring of sample of FRII-type radio quasars. The op... more We present preliminary results of optical monitoring of sample of FRII-type radio quasars. The optical observations were made with three telescopes, among them one robotic, spanning a time interval longer than two years. Variability in the range of a fraction of a magnitude was observed for all eight targets. We applied the structure function to analyse the brightness changes. The slope of the structure function is only consistent with the disk instability model for two sources; the other sources show values between of the disk instability and starburst models. Finally we argue that such monitoring would be most suitable as a long-term, complementary program for robotic telescopes.
The Astronomical Observatory of the Jagiellonian University produced a large number of photograph... more The Astronomical Observatory of the Jagiellonian University produced a large number of photographic plates of various types and sizes over many decades. With the demise of emulsion-based photography as an observational technique in the latter years of the 20th century, the plate collection was neglected, and many plates have been destroyed or damaged by water or accidents, while written records have been lost. As part of the AstroGrid-PL project we were able to scan the surviving plates and (known) records and are in the process of identifying and publishing the images, some of which record observations of comets. Here we present some examples from plates made with the Zeiss Tessar Astrograph.
We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating... more We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated XCOV25. The Fourier transform (FT) of the light curve contains power between 1000 and 4000 μHz, with the dominant peak at 1234 μHz. We find 27 independent frequencies distributed in 10 modes, as well as numerous combination frequencies. Our discussion focuses on a new asteroseismological analysis of GD358, incorporating the 2006 data set and drawing on 24 years of archival observations. Our results reveal that, while the general frequency locations of the identified modes are consistent throughout the years, the multiplet structure is complex and cannot be interpreted simply as l = 1 modes in the limit of slow rotation. The high-k multiplets exhibit significant variability in structure, amplitude and frequency. Any identification of the m components for the high-k m...
We report extensive photometry of frequently outbursting dwarf nova IX Draconis. During five mont... more We report extensive photometry of frequently outbursting dwarf nova IX Draconis. During five months of observations the star went into three superoutbursts and seven ordinary outbursts. This allowed us to determine its supercycle and cycle lengths as equal to 54 +/- 1 and 3.1 +/- 0.1 days, respectively. During the Sep 2003 superoutburst, which had the best observational coverage, IX Dra displayed clear superhumps with a period of Psh=0.066968(17) days. This period was constant during the whole superoutburst. Another period, which was clearly present in the light curve of IX Dra in superoutburst, had a value of 0.06646(6) days and we interpret it as the orbital period of the binary. Thus IX Dra is the first SU UMa star showing orbital modulation during the entire superoutburst. The beat between these two periods is the main cause of an unusual phase reversal of superhumps - a phenomenon which was previously observed in ER UMa. If our interpretation of the second periodicity is correc...
As part of the AstroGrid-PL project, we have implemented a large scale data management system for... more As part of the AstroGrid-PL project, we have implemented a large scale data management system for the Polish astronomical community within the framework of the PLGrid Plus project, with built-in metadata services, replication and distributed storage based on the well-established iRODS middleware. In parallel, we have implemented the Polish Virtual Observatory, which provides access, search, retrieval and in situ processing for this data using the protocols and standards established by the International Virtual Observatory Alliance (IVOA). These standards are already in use at astronomical facilities across the globe, and implementing them within the framework of AstroGrid-PL and the PLGrid Plus project enables us not only to provide advanced data retrieval services to our users, but also to leverage a large body of existing astronomical data analysis software and give our users access to external data resources provided on the same principles.
The first Global e-Competition on Astronomy and Astrophysics was held on-line in September-Octobe... more The first Global e-Competition on Astronomy and Astrophysics was held on-line in September-October 2020 as a replacement for the International Olympiad on Astronomy and Astrophysics, which was postponed due to the ongoing pandemic caused by COVID-19. Despite the short time available for organisation, the competition was run successfully with 325 students from over 42 countries participating with no major issues. The feedback from the participants was positive and reflects the ways in which such events can boost interest in astronomy and astronomy education. With on-line activities set to be more prevalent in the future, we present an overview of the competition process and some of the lessons learned in hindsight as a guide for other event organisers.
Radial-velocity measurements and sine-curve fits to the orbital radial velocity variations are pr... more Radial-velocity measurements and sine-curve fits to the orbital radial velocity variations are presented for the last eight close binary systems analyzed the same way as
Radial velocity measurements and simple sine-curve Ðts to the orbital velocity variations are pre... more Radial velocity measurements and simple sine-curve Ðts to the orbital velocity variations are presented for the third set of 10 close binary systems : CN And, HV Aqr, AO Cam, YY CrB, FU Dra, RZ Dra, UX Eri, RT LMi, V753 Mon, and OU Ser. All systems except two (CN And and RZ Dra) are contact, double-line spectroscopic binaries, with four of them (YY CrB, FU Dra, V753 Mon, and OU Ser) being the recent discoveries of the Hipparcos satellite project. The most interesting object is V753 Mon with the mass ratio closest to unity among all contact systems (q \ 0.970^0.003) and large total mass [(M 1 Several of the studied systems are prime candidates for combined light and ] M 2 ) sin3 i \ 2.93^0.06]. radial velocity synthesis solutions.
Improvements in detector technology mean that today astronomy, like other experimental sciences, ... more Improvements in detector technology mean that today astronomy, like other experimental sciences, is dominated by the rapid accumulation of extremely large data sets. For example, a typical single night of observations at a telescope equipped with a CCD camera can produce several gigabytes of raw data, while new survey telescopes such as the LSST are projected to produce up to 1 terabyte of data per night. This means that it is no longer possible for a single researcher to store and process the data on their own workstation, and indeed it is not even possible for a single researcher to analyze all the available data contained in even their own observations (which may contain information about hundreds or thousands of additional objects in the same field of view as the target star or galaxy). Thus a new approach to data storage, retrieval and processing is required, which harnesses geographically distributed computing resources to provide storage, processing, and sharing of these larg...
We present preliminary results of optical monitoring of sample of FRII-type radio quasars. The op... more We present preliminary results of optical monitoring of sample of FRII-type radio quasars. The optical observations were made with three telescopes, among them one robotic, spanning a time interval longer than two years. Variability in the range of a fraction of a magnitude was observed for all eight targets. We applied the structure function to analyse the brightness changes. The slope of the structure function is only consistent with the disk instability model for two sources; the other sources show values between of the disk instability and starburst models. Finally we argue that such monitoring would be most suitable as a long-term, complementary program for robotic telescopes.
The Astronomical Observatory of the Jagiellonian University produced a large number of photograph... more The Astronomical Observatory of the Jagiellonian University produced a large number of photographic plates of various types and sizes over many decades. With the demise of emulsion-based photography as an observational technique in the latter years of the 20th century, the plate collection was neglected, and many plates have been destroyed or damaged by water or accidents, while written records have been lost. As part of the AstroGrid-PL project we were able to scan the surviving plates and (known) records and are in the process of identifying and publishing the images, some of which record observations of comets. Here we present some examples from plates made with the Zeiss Tessar Astrograph.
We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating... more We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated XCOV25. The Fourier transform (FT) of the light curve contains power between 1000 and 4000 μHz, with the dominant peak at 1234 μHz. We find 27 independent frequencies distributed in 10 modes, as well as numerous combination frequencies. Our discussion focuses on a new asteroseismological analysis of GD358, incorporating the 2006 data set and drawing on 24 years of archival observations. Our results reveal that, while the general frequency locations of the identified modes are consistent throughout the years, the multiplet structure is complex and cannot be interpreted simply as l = 1 modes in the limit of slow rotation. The high-k multiplets exhibit significant variability in structure, amplitude and frequency. Any identification of the m components for the high-k m...
We report extensive photometry of frequently outbursting dwarf nova IX Draconis. During five mont... more We report extensive photometry of frequently outbursting dwarf nova IX Draconis. During five months of observations the star went into three superoutbursts and seven ordinary outbursts. This allowed us to determine its supercycle and cycle lengths as equal to 54 +/- 1 and 3.1 +/- 0.1 days, respectively. During the Sep 2003 superoutburst, which had the best observational coverage, IX Dra displayed clear superhumps with a period of Psh=0.066968(17) days. This period was constant during the whole superoutburst. Another period, which was clearly present in the light curve of IX Dra in superoutburst, had a value of 0.06646(6) days and we interpret it as the orbital period of the binary. Thus IX Dra is the first SU UMa star showing orbital modulation during the entire superoutburst. The beat between these two periods is the main cause of an unusual phase reversal of superhumps - a phenomenon which was previously observed in ER UMa. If our interpretation of the second periodicity is correc...
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Papers by Greg Stachowski