Astronomical Institute Research Articles

AstroEdu Conference 2023 - Preface

A collection of astronomy education endeavours from around the world presented at the AstroEdu Conference 2023 hosted by the University of Toronto - Dunlap Institute for Astronomy and Astrophysics.

KINEMATIC PARAMETERS, PHYSICAL CHARACTERISTICS, AND CHEMICAL COMPOSITION OF SELECTED METEOR BODIES

Background. Meteoroids can reach the Earth and penetrate its atmosphere creating meteor phenomena. Kinematic parameters, physical characteristics, and chemical compositions of the observed meteor bodies provide information about the properties of their parent bodies — comets and asteroids. On the other hand, these parameters can reflect the physical conditions of meteor- oids staying in different parts of the Solar System and beyond. Methods. The meteor data analyzed in this work were obtained from observations using the automatical video and spectral meteor patrol (AVSMP) of the Institute of Astronomy of V. N. Karazin Kharkiv National University. The methods of meteor astronomy and spectroscopy make it possible to determine the kinematic parameters, physical properties, and chemical com- position of the meteoroids that we studied. Results. The paper presents the research results of meteors brighter than 0m that were recorded by the multi-stations method. These meteors also have spectral observations. For the selected 12 meteors, we obtained the coordinates of meteor radiants on the celestial sphere, the parameters of the atmospheric trajectories of meteor bodies, and the heliocentric orbital parameters of the observed meteoroids for the epoch (J2000). The extra-atmospheric masses of meteoroids were determined from photometric data. The identified emission lines detected in meteor spectra were analyzed. The software developed by the authors of this paper for me- teor spectra processing was used. Qualitative and quantitative analyses of the chemical composition of meteor bodies were carried out. During the quantitative analysis, the values of the relative intensities of the Fe I-15, Mg I-2, and Na I-1 lines were determined. Conclusions. Kinematic parameters and elements of heliocentric orbits presented in this work indicate that the observed me- teor bodies belong to meteor showers and their comets, such as Perseids, Leonids, and Southern Taurids. Some meteor bodies are sporadic. The calculated masses of meteoroids have some scatter of values, but they are generally consistent with observa- tions of other authors in the range of absolute values of the meteor brightness -2m…+1.5m. It was found that some of the studied meteor bodies are Fe-poor or Na-poor in their chemical composition.

Scientific (Astro) tourism activities in Armenia and in South West and Central Asian region

Scientific Tourism activities have been initiated in a number of countries during the recent decades. Armenia was among the first countries developing Scientific Tourism and most probably the first to develop Astro Tourism. We were the first to introduce the term “Astronomical Tourism” (or “Astro Tourism”). This includes visits to astronomy-related sites (astronomical observatories, astronomical institutes, astronomy-related university departments, ancient sky/astronomy-related sites, medieval universities, planetariums, space/astronomy museums, etc.) but not only. The organization of astronomical meetings, schools, camps and other events with involvement of many visitors, we also consider as Astro Tourism activities. We give an overview of our activities, including the main project; development of Astro Tourism in the SWCA region. A detailed study of Astro Tourism sites in Armenia, Georgia, Iran, Kazakhstan, Tajikistan, Turkey and (in addition) Uzbekistan was carried out, namely, modern astronomical observatories and institutes, ancient astronomy-related sites, medieval universities, planetariums, astronomy/space museums, etc. A webpage was built representing Astro Tourism in SWCA region. We also discuss the Scientific Tourism and Tourism in general as disciplines for studies and not only as service. We will share our experience on Scientific/Astro tourism activities and discuss how different items may be implemented in different regions.

Solar physics and space weather research at the Institute of Astronomy and NAO - BAS: Solar cycle trends of space weather drivers

Abstract This report summarizes the available space weather catalogs hosted at https://catalogs.astro.bas.bg/, supported by the Institute of Astronomy and National Astronomical Observatory – Bulgarian Academy of Sciences. Namely solar flares, solar energetic protons, electron associated radio bursts and geomagnetic storms are considered. All these comprehensive records of analysed events are provided with an open access with the aim to be supported in the future. The lists cover solar cycles 23 and 24 (1996–2019) and contain the relevant parameters and their associated solar and/or interplanetary origin. The focus of this report is the solar cycle trend of solar and geomagnetic phenomena, indicating reduced productivity of either type of events in the last solar cycle and offsets with respect to the sunspot numbers.

Probing the inner Galactic halo with blue horizontal-branch stars

Context. Stars that are found on the blue horizontal-branch (BHB) evolved from low-mass stars that have completed their core hydrogen-burning main sequence (MS) stage and undergone the helium flash at the end of their red giant phase. Hence, they are very old objects that can be used as markers in studying galactic structure and formation history. The fact that their luminosity is virtually constant at all effective temperatures also makes them good standard candles. Aims. We have compiled a catalogue of BHB stars with stellar parameters calculated from spectral energy distributions (SEDs) constructed using data from multiple large-scale photometric surveys. In addition, we update our previous Gaia Early Data Release 3 (EDR3) catalogue of BHB stars with parallax errors less than 20% by using the SED results to define the selection criteria. The purpose of these catalogues is to create a set of BHB star candidates with reliable stellar parameters. In addition, they provide a more complete full-sky catalogue with candidate objects found along the whole BHB from where RR-Lyrae are found on the instability strip to the extreme horizontal-branch (EHB). Methods. We selected a large dataset of Gaia Data Release 3 (DR3) objects based only on their position on the colour-magnitude diagram (CMD), along with the tangential velocity and parallax errors. The SEDs were then used to evaluate contamination levels in the dataset and derive optimised data quality acceptance constraints. This allowed us to extend the Gaia DR3 colour and absolute magnitude criteria further towards the EHB. The level of contamination found using SED analysis was confirmed by acquiring spectra using the Ondrejov Echelle spectrograph, attached to the Perek 2m telescope at the Astronomical Institute of the Czech Academy of Sciences. Results. We present a catalogue of 9172 Galactic halo BHB candidate stars with atmospheric and stellar parameters calculated from synthetic SEDs. We also present an extended Gaia DR3-based catalogue of 22 335 BHB candidate stars with a wider range of effective temperatures and Gaia DR3 parallax errors of less than 20%. This represents an increase of 33% compared to the our 2021 catalogue, with a contamination level of 10%.

GPR and ERT Exploration in the Western Cemetery in Giza, Egypt

ABSTRACTA geophysical exploration employing ground‐penetrating radar (GPR) and electrical resistivity tomography (ERT) was conducted at the Western Cemetery, Giza, Egypt, in 2021–23 by a joint research team of Higashi Nippon International University, Tohoku University and the National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Egypt. We believe we found an anomaly: a combination of a shallow structure connected to a deeper structure. The shallow structure, which is L‐shaped in the horizontal plane, 10 m by 10 m, was clearly imaged by GPR. It seems to have been filled with sand, which means it was backfilled after it was constructed. It may have been an entrance to the deeper structure. Its depth is of up to 2 m, measured from the ground surface. Below this structure, ERT reveals a highly electrically resistive anomaly, which extends over an area of about 10 m by 10 m. The depth of the structure is about 5–10 m below the surface. Electrically resistive material in a sand dune can be a mixture of sand and gravel, including sparse spacing or air voids within it. Neither GPR nor ERT could identify the properties of the anomaly.

AIUB-GRACE gravity field solutions for G3P: processing strategies and instrument parameterization

Abstract. This paper discusses strategies to improve the Gravity Recovery And Climate Experiment (GRACE) monthly solutions computed at the Astronomical Institute of the University of Bern (AIUB) which are contributing to the Horizon 2020 project G3P – Global Gravity-based Groundwater Product. To improve the AIUB-GRACE gravity field solutions, we updated the use of the Level-1B observations, adapted the background models, and improved the processing strategies in terms of instrument screening and parameterization. We used the Release 3 K-band product (KBR) and star camera data (L1B RL03), and we adopted Release 6 of the Atmospheric and Ocean De-aliasing (AOD1B RL06) product. For the accelerometer parameterization, we used arc-wise full scale factor matrix and arc-wise third-order polynomial biases. The new accelerometer parameterization is effective in reducing noise over the oceans in gravity field solutions, especially for the late years of the GRACE mission when the thermal control was switched off. In this paper, we show that the outliers in the KBR antenna offset correction (AOC) are projected into the range rate residuals; therefore, we used the KBR AOC as the main source for outlier detection and eliminated the AOC above a threshold for all data before the gravity field processing. The full time series of GRACE AIUB-G3P gravity field solutions (Darbeheshti et al., 2023b) is available at https://doi.org/10.5880/ICGEM.2023.001.

Stellar feedback impact on the ionized gas kinematics in the dwarf galaxy Sextans B

ABSTRACT We investigated the ionized and atomic gas kinematics and excitation state in the central region of ongoing star formation of the nearby low-metallicity dwarf galaxy Sextans B. The analysis is based on the new observations performed in the H α emission line with high resolution (R ∼ 16 000) scanning Fabry–Perot interferometer at the 6-m BTA Special Astrophysical Observatory of the Russian Academy of Sciences telescope, and on the long-slit spectral observations at the 9.2-m SALT and 2.5-m Caucasian Mountain Observatory of Sternberg Astronomical Institute of Moscow State University telescopes. Strong non-circular gas motions detected in the studied regions probably resulted from the off-plane gas motions and impact of stellar feedback. We identified six regions of elevated H α velocity dispersion, five of which exhibit asymmetric or two-component H α line profiles. Three of these regions are young (<1.1 Myr) expanding ($V_\mathrm{exp} \sim 25-50 \, \mbox{km}\, \mbox{s}^{-1}$) superbubbles. We argue that at least three regions in the galaxy could be supernova remnants. We conclude that supernovae feedback is the dominant source of energy for superbubbles in Sextans B, which is expected for such a low metallicity, although we cannot rule out a strong impact of pre-supernova feedback for one superbubble.

Simulation of spectral observations of an eruptive prominence

The paper presents the results of an analysis of observations of an eruptive prominence on the MFS and HSFA2 spectrographs of the Ondřejov Observatory (Astronomical Institute, Czech Republic) in the lines of hydrogen, helium and calcium. After processing the spectra, the integral radiation fluxes in the lines were determined and a theoretical calculation of the physical parameters of the plasma was carried out using a model in the absence of local thermodynamic equilibrium. A comparison of the observed and calculated values showed that the observed radiation fluxes in the lines can be explained in a model of stationary gas radiation taking into account the opacity in the spectral lines. To calculate theoretical fluxes, in some cases it was necessary to introduce radiation from several layers with different temperatures and heights. The calculated radiation fluxes agree with the observed ones with an accuracy of 10%. As a result of the simulation, the main parameters of the prominence plasma were obtained: temperature, concentration, etc. The values of radiation fluxes in the spectral lines indicate the inhomogeneity of the emitting gas, and there may be regions next to each other whose temperatures differ by an order of magnitude.

The International Astronomical Search Collaboration (IASC)—Citizen Scientist System for Asteroid Discovery

We describe a citizen science asteroid detection system developed by the International Astronomical Search Collaboration (IASC) and the Institute for Astronomy at the University of Hawaii, utilizing data from the Pan-STARRS telescopes. The goals of this project are to (i) educate and engage citizen scientists (mostly high school students) in science and astronomy, (ii) search for new asteroids to extend the limiting magnitudes of existing asteroid surveys, and (iii) find missed Near-Earth Objects (NEOs—objects with perihelia q < 1.3 au) to support planetary defense efforts. Over the past 15 yr, 50,000 citizen scientists from 96 countries around the world have detected ∼12,000 main-belt asteroids and ∼5 NEOs. Citizen scientists use the software Astrometrica during scheduled campaigns to search for and measure asteroid astrometry and photometry, and submit the data to IASC for vetting. Candidate detections not already submitted by Pan-STARRS are then submitted to the Minor Planet Center, and are typically ∼0.30 ± 0.07 mag fainter.

VLF Signal Variations Seen in the Bucharest Observatory Recordings .

his paper presents a new instrument setup at the Bucharest Observatory of the Astronomical Institute of the Romanian Academy, as well as preliminary results using this setup. It consists of records of VLF (very low frequency) perturbations using a superSID instrument. During March and December 2022 various mounts and settings tests have been performed. Starting October we obtained satisfactory data. We report on detecting the signature of moderate to intense solar flares (M and X–class). In this configuration, the C–class solar flares are less distinguishable from the background noise.

The 4m International Liquid Mirror Telescope Project

The International Liquid Mirror Telescope (ILMT) project is a scientific collaboration in observational astrophysics between the Liège Institute of Astrophysics and Geophysics (Liège University, Belgium), the Aryabatta Research Institute of observational sciencES (ARIES, Nainital, India) and several Canadian universities (British Columbia, Laval, Montréal, Toronto, Victoria and York). Meanwhile, several other institutes have joined the project: the Royal Observatory of Belgium, the National University of Uzbekistan and the Ulugh Beg Astronomical Institute (Uzbekistan) as well as the Poznan Observatory (Poland). The Liège company AMOS (Advanced Mechanical and Optical Systems) has built the telescope structure that has been erected on the ARIES site in Devasthal (Uttarakhand, India). It is the first liquid mirror telescope being dedicated to astronomical observations. First light was obtained on 29th April 2022 and commissioning is being conducted at the present time. In this short article, we describe and illustrate the main components of the ILMT. We also highlight the ILMT papers presented during the third BINA workshop, which discuss various aspects of the ILMT science programs.

Combined monthly GRACE-FO gravity fields for a Global Gravity-based Groundwater Product

SUMMARY The Combination Service for Time-variable Gravity fields (COST-G) operationally provides combinations of monthly Earth gravity field models derived from observations of the microwave ranging instrument of the GRACE Follow-on (GRACE-FO) satellite mission, applying the quality control and combination methodology originally developed by the Horizon 2020 project European Gravity Service for Improved Emergency Management for the data of the GRACE satellites. In the frame of the follow-up Horizon 2020 project Global Gravity-based Groundwater Product (G3P), the GRACE-FO combination is used to derive global grids of groundwater storage anomalies. To meet the user requirements and achieve optimal signal-to-noise ratio, the combination has been further developed and extended to incorporate: • new time-series based on the alternative accelerometer transplant product generated in the frame of the project by the Institute of Geodesy at the Graz University of Technology, which specifically improves the estimation of the C30 coefficient and also reduces the noise at medium to short wavelengths, and • the new time-series AIUB–GRACE-FO–RL02 of monthly GRACE-FO gravity fields, which is derived at the Astronomical Institute of the University of Bern by applying empirical noise modelling techniques. The COST-G quality control confirms the consistency of the contributing GRACE-FO time-series concerning the signal amplitude of seasonal hydrology in large river basins and the secular mass change in polar regions, but it also indicates rather diverse noise characteristics. The difference in the noise levels is taken into account in the combination process by relative weights derived by variance component estimation on the solution level. The weights are expected to be inverse proportional to the noise levels of the individual gravity field solutions. However, this expectation is violated when applying the weighting scheme as developed for the GRACE combination. The reason is found in the high-order coefficients of the gravity field, which are poorly determined from the low–low range-rate observations due to the observation geometry and suffer from aliasing due to the malfunctioning accelerometer onboard one of the GRACE-FO satellites. Hence, for the final G3P-combination a revised weighting scheme is applied where the gravity field coefficients beyond order 60 are excluded from the determination of the weights. The quality of the combined gravity fields is assessed by comparison of the noise content and the signal-to-noise ratio with the individual time-series. Independent validation is provided by the COST-G validation centre at the GFZ German Research Centre for Geosciences, where orbit fits of the low-flying Gravity and steady-state Ocean Circulation Explorer satellite are performed that confirm the high quality of the combined GRACE-FO gravity fields. By the end of the G3P project, the new combination scheme is implemented by COST-G as the new COST-G–GRACE-FO–RL02 and continued to be used for the operational GRACE-FO combination.

Present status of UBAI plate archive

This paper discusses a photographic plate archive of the Ulugh Beg Astronomical Institute (UBAI) of the Uzbek Academy of Sciences, the history of photometric observations, the current state of photometric plates, and the process of their digitization. We will talk about telescopes used for observations, their characteristics and observations. In addition, we will also talk about the preparation of photographic plates for scanning. Also, the work carried out in the “UBAI-SHAO scientific and technical project” on digitization of photographic plates in the UBAI archive at the Shanghai Astronomical Observatory (SHAO) of the Chinese Academy of Sciences and future work will be reviewed and discussed.

MODERN STELLAR ASTRONOMY – 2022

We provide an analytic review of problems of the modern stellar astronomy. It mostly based on talks presented at the twelfth annual conference on Modern Stellar Astronomy, held in Caucasian Mountain Observatory of Sternberg Astronomical Institute (Kislovodsk, Russia) in November 2022.

Optical Identification and Spectroscopic Redshift Measurements of 216 Galaxy Clusters from the SRF/eROSITA All-Sky Survey

We present the results of the optical identification and spectroscopic redshift measurements of216 galaxy clusters detected in the SRG/eROSITA all-sky X-ray survey. The spectroscopic observationswere performed in 2020–2023 with the 6-m BTA telescope at the Special Astrophysical Observatory ofthe Russian Academy of Sciences, the 2.5-m telescope at the Caucasus Mountain Observatory of theSternberg Astronomical Institute of the Moscow State University, the 1.6-m AZT-33IK telescope atthe Sayan Solar Observatory of the Institute of Solar–Terrestrial Physics of the Siberian Branch of theRussian Academy of Sciences, and the 1.5-m Russian–Turkish telescope (RTT-150) at the TU¨ BI˙ TAKObservatory. For all of the galaxy clusters presented here the spectroscopic redshift measurements havebeen obtained for the first time. Of these, 139 galaxy clusters have been detected for the first time in theSRG/eROSITA survey and 22 galaxy clusters are at redshifts zspec 0.7, including three at zspec 1.Deep direct images with the rizJK filters have also been obtained for four distant galaxy clusters atzspec 0.7. For these observations we chose the most massive clusters and, therefore, most of the galaxyclusters presented here with the spectroscopic redshifts measured by us will most likely enter in future intothe cosmological samples of galaxy clusters from the SRG/eROSITA survey.

Search for Signs of Sublimation-Driven Dust Activity of Primitive-Type Asteroids Near Perihelion

—In December 2021 to February 2022, the UBVRI photometry of 29 primitive-type asteroids of the Main Belt, being near the perihelion distances, was carried out at the 0.6-meter RC600 semiautomatic telescope of the Caucasus Mountain Observatory (CMO) of the Sternberg Astronomical Institute, Moscow State University. These observations, as well as the data processing and analysis, were aimed at searching for supposed sublimation-driven dust activity on asteroids under maximal subsolar temperatures. Among the tasks to be accomplished was the comparison of the physical and dynamic parameters of active and inactive asteroids. The main result is that substantial spectral signs of quasi-simultaneous sublimation-driven dust activity were detected on six primitive-type asteroids of the Main Belt—145 Adeona, 302 Clarissa, 322 Phaeo, 435 Ella, 690 Wratislavia, and 779 Nina (on 302 Clarissa, 322 Phaeo, 435 Ella, and 690 Wratislavia—for the first time). These six asteroids represent ~21% of all bodies included in the observation program. Probable spectral manifestations of activity at a lower intensity level were detected for the first time on five more asteroids—424 Gratia, 751 Faina, 762 Pulcova, 778 Theobalda, and 859 Bouzaréah. On 145 Adeona and 779 Nina, sublimation-driven dust activity near perihelion was registered for the third time for the last ten years; this time interval corresponds to about three orbital periods of these asteroids around the Sun. We consider the circumstances due to which five of the listed asteroids possess families. General processes and conditions that could and/or can influence the portion of primitive-type asteroids that quasi-simultaneously show signs of sublimation-driven dust activity are discussed.

Search for Signs of Sublimation-Driven Dust Activity of Primitive-Type Asteroids Near Perihelion

In December 2021 to February 2022, the UBVRI photometry of 29 primitive-type asteroids of the Main Belt, being near the perihelion distances, was carried out at the 0.6-meter RC600 semiautomatic telescope of the Caucasus Mountain Observatory (CMO) of the Sternberg Astronomical Institute, Moscow State University. These observations, as well as the data processing and analysis, were aimed at searching for supposed sublimation-driven dust activity on asteroids under maximal subsolar temperatures. Among the tasks to be accomplished was the comparison of the physical and dynamic parameters of active and inactive asteroids. The main result is that substantial spectral signs of quasi-simultaneous sublimation-driven dust activity were detected on six primitive-type asteroids of the Main Belt—145 Adeona, 302 Clarissa, 322 Phaeo, 435 Ella, 690 Wratislavia, and 779 Nina (on 302 Clarissa, 322 Phaeo, 435 Ella, and 690 Wratislavia—for the first time). These six asteroids represent ~21% of all bodies included in the observation program. Probable spectral manifestations of activity at a lower intensity level were detected for the first time on five more asteroids— 424 Gratia, 751 Faina, 762 Pulcova, 778 Theobalda, and 859 Bouzaréah. On 145 Adeona and 779 Nina, sublimation-driven dust activity near perihelion was registered for the third time for the last ten years; this time interval corresponds to about three orbital periods of these asteroids around the Sun. We consider the circumstances due to which five of the listed asteroids possess families. General processes and conditions that could and/or can influence the portion of primitive-type asteroids that quasi-simultaneously show signs of sublimation-driven dust activity are discussed.

Assessment of the Astroclimatic Conditions of the Observation Complex at the Institute of Astronomy of Kharkiv National University

Assessment of the Astroclimatic Conditions of the Observation Complex at the Institute of Astronomy of Kharkiv National University

Improving hardware/software interface management in systems of systems through documentation as code

ContextThe management of Interface Control Documents (ICDs) has shown to be a major pain point in the architecting processes of Systems of Systems (SoS).ObjectiveThis work aims to improve on previously identified ICD management issues using the documentation-as-code philosophy as a potential basis for a treatment, and in collaboration with practitioners.MethodWe conducted a Technical Action Research (TAR) study with a group of engineers at the Netherlands Radio Astronomy Institute (ASTRON), in the context of the LOFAR radio telescope. An additional research instrument, in the form of an expert panel, was used to evaluate the transferability of the proposed treatment to alternative domains.ResultsIn-depth insights on previously identified interface management issues were gained. Based on these insights a functional proof-of-concept was developed aimed at addressing these issues following the documentation-as-code principles. In addition to receiving overall positive reviews from practitioners and experts, further areas of improvement and transferability considerations for future work were identified.ConclusionsThe proposed approach, which to our knowledge has not been explored before in this context, is promising to address some of the recurring interfacing-related issues with directed SoS in multiple engineering domains. This could be done mainly by enforcing consistency and completeness on both text-based and formal elements of the ICDs, and turning ICDs into single sources of truth for the architecting processes of large scale SoS.