Workshop 2022

Workshop “Photometry and polarimetry of asteroids: past and future”

Institute of Astronomy of V.N. Karazin National University, Kharkiv, Ukraine

February 15, 2022

The workshop is organized in honor of Prof. Dmitrij Lupishko who celebrates his 80th anniversary, of which 45 years has been devoted to asteroid study.


Asteroid research in Kharkiv: How we started 45 years ago

D. F. Lupishko

Institute of Astronomy, V.N. Karazin Kharkiv National University, Ukraine

This is a brief historical excursion about how we started researching asteroids in Kharkiv and how we coordinated these researches throughout the country

NEOROCKS PROJECT: the relevance of photometry, spectrophotometry and polarimetry in determining some of the key properties of potentially hazardous asteroids.

Marcello Fulchignoni1, Maria Antonietta Barucci1, Mirel Birlan2, Sonia Fornasier1, Tetiana Hromakina1, Giovanni Poggiali1, Sandra Potin1

1LESIA, Observatoire de Paris, Université PSL, CNRS, Université de Paris, Sorbonne Université, 5 place Jules Janssen, 92195 Meudon, France
2IMCCE, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, 5 place Jules Janssen, 92195 Meudon, France

NEOROCKS - The NEO Rapid Observation, Characterization and Key Simulations is a project in the framework of the programme H2020 of the European commission, which includes 13 partners (both scientific institutions and companies) from eight European Countries.

NEOROCKS main objectives are the improvement of our knowledge on the physical characterization of very small Near Earth Objects [NEO] (from meters to few hundreds of meters in size) and its implications in

  • the understanding of the origin/evolution of this population
  • planetary defence.

These goals are achieved by performing the astronomical observations of very small bodies population and developing the related models needed to derive NEOs dynamical and physical properties relevant to planetary defence approaches. All the obtained data will allow us to rank the NEO’s physical and chemical properties in order of importance for a given purpose: the ranking will be different for different activities (mitigation/exploration/exploitation…).

We are describing in particular the observational activities concerning the photometry, the spectrophotometry and the polarimetry of small asteroids with particular interest in theways in which the results of the observations contribute in determining relevant physical properties of these bodies.

The Calern Asteroid Polarimetric Survey: State of the art

A. Cellino1, Ph. Bendjoya2, J.-P. Rivet2, S. Bagnulo3, M. Devogele4, L. Abe2

1INAF - Osservatorio Astrofisico di Torino, I-10025 Pino Torinese, Italy
2Observatoire de la Côte d'Azur, Université de la Côte d'Azur, CNRS, Laboratoire Lagrange, 06304 Nice Cedex 4, France
3Armagh Observatory & Planetarium, College Hill, Armagh, UK
4Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA

The Calern Asteroid Polarimetric Survey (CAPS) started in 2017 and, with some interruptions due to the recent pandemics, has produced so far a large amount of new polarimetric measurements of asteroids belonging to a large variety of taxonomic classes, including rare objects as Barbarians and F-class asteroids, near-Earth asteroids, and dynamical family members.

In this presentation the current state of the art will be summarized, including a refined estimate of the error bars of the measurements, based upon a large amount of data for polarization standard stars collected over several years of observations. Examples of phase-polarization curves which can be computed using CAPS data together with data available in the literature will be shown. Some new results about Barbarians will be mentioned, and several other applications that are already under development using currently available data will also be discussed. Some planned improvements of CAPS using better instrumentation will be mentioned.

Comets, asteroids and planetary satellites studied with new two-channel polarimeters of Crimean Astrophysical Observatory and Peak Terskol Observatory in 2018-2021

N. Kiselev1, V. Rosenbush2,3, A. Savushkin1, A. Zhuzhulina1, N. Karpov1

1Crimean Astrophysical Observatory
2Main Astronomical Observatory of the National Academy of Sciences, Kyiv, Ukraine
3Astronomical Observatory of Taras Shevchenko National University of Kyiv, Ukraine

The potential of new aperture polarimeters will be discussed. We will present the phase curves of polarization of selected comets, asteroids and satellites of Jupiter and Saturn, which were obtained in 2018-2021.

Optimization of spectro-photometric surveys towards asteroid taxonomy

Dagmara Oszkiewicz

Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland

Asteroid taxonomies provide a link to surface composition and mineralogy of those objects. Asteroid types or classes are typically assigned based on spectral measurements in visible, or near-infrared (or both) wavelenghts. Those types of observations are time-consuming and challenging to obtain for a large number of asteroids. On the other hand, a growing amount of space and ground-based surveys delivers multi-filter photometry, which is often used in predicting and assigning asteroid types. We quantify the importance and performance of different asteroid spectral features, parameterizations, and methods in predicting the asteroid types. Furthermore, we identify the key spectral features that can be used to optimize future surveys toward asteroid characterization. We found that multilayer perceptron and gradient boosting perform best in predicting asteroid types and complexes. Additionally we show that the top five features (spectral slope, and reflectance values at 1.05, 0.9, 0.65 and 1.1 μm) are enough to obtain a balanced accuracy of 93% for the prediction of complexes and six top features (spectral slope, reflectance at 1.4, 1.05, 0.9, 0.95, 0.65 μm) to obtain 81% balanced accuracy for prediction of taxonomic types. To optimize future surveys towards asteroid taxonomy we recommend using filters that cover those top features.

PRISMA: an italian fireball network for the recovery of freshly fallen meteorites

Daniele Gardiol

Istituto Nazionale di Astrofisica (INAF, Osservatorio Astrofisico di Torino, via Osservatorio 20, Pino Torinese (Italia)

PRISMA is the Italian fireball network dedicated to the observation of bright meteors. It is active since 2016 and is a collaboration involving more than 60 institutes coordinated by the Italian National Institute for Astrophysics (INAF). To date PRISMA counts more than 60 all-sky detectors and has observed more than 2000 bright meteors, five of them being meteorite-dropping fireballs with a predicted strewn-field over the Italian territory, and one leading to a successful meteorite recovery (Cavezzo, January 2020). Being partner of the FRIPON collaboration, PRISMA can contribute to the study of NEO, e.g. providing valuable freshly fallen material and orbital elements of bodies associated to the observed events.

The first instrumentally documented fall of an iron meteorite: orbit and possible origin

Ihor Kyrylenko1, Oleksiy Golubov1, Ivan Slyusarev1, Jaakko Visuri2, Maria Gritsevich2,3,4, Yurij N. Krugly1, Irina Belskaya1, Vasilij G. Shevchenko1

1Institute of Astronomy of V. N. Karazin Kharkiv National University, Ukraine
2Finnish Fireball Network, Ursa Astronomical Association, Finland
3Finnish Geospatial Research Institute, Geodeetinrinne 2, Masala 02430, Finland
4Department of Physics, University of Helsinki, Gustaf Hallsromin katu 2a, Helsinki 00014, Finland

A bright fireball observed on November 7, 2020, over Scandinavia, produced the first iron meteorite with a well-determined pre-atmospheric trajectory. We determine the orbit of this meteoroid and find that it demonstrates no close affinity with the orbit of any known asteroid. We find that the meteoroid (or its parent body) most probably entered the near-Earth orbit from the main asteroid belt via either v6 secular resonance with Saturn (61%) or 3:1 mean-motion resonance with Jupiter (28%). The long YORP timescale of the meteoroid suggests that it could have been produced in the main asteroid belt and survived the journey to the Near-Earth orbit.

Determination of asteroid densities by the Yarkovsky effect

Oleksiy Golubov

Institute of Astronomy, V.N. Karazin Kharkiv National University, Ukraine

The Yarkovsky effect is a radiation pressure force arising from the asymmetric emission of thermal radiation by a rotating body. The orbital drift of an asteroid due to the Yarkovsky effect depends on the asteroid's density, which has been successfully used to determine densities of several asteroids with measured Yarkovsky orbital drift. Gaia space mission should substantially increase the number of asteroids with the measured Yarkovsky effect, turning it into one of the most powerful tools for asteroid density determination, but warranting new precise and universal instruments to process the Yarkovsky accelerations. We present a simple but robust mathematical model of the Yarkovsky effect, which accounts for the asteroid's shape and thermal properties, use it to create a pipeline for the asteroid density determination, and present the first results of our pipeline.

Characterisation of the V-type asteroids from Cell I and Cell II

Volodymyr Troianskyi1,2, Pawel Kankiewicz3, and Dagmara Oszkiewicz1

1Astronomical Observatory Institute, Faculty of Physics, A. Mickiewicz University, Sloneczna 36, 60-286 Poznan, Poland
2Astronomical Observatory of Odessa I.I.Mechnikov National University, Marazlievskaya 1v, 65014 Odessa, Ukraine
3Institute of Physics, Jan Kochanowski University, Uniwersytecka 7, 25-406 Kielce, Poland

Through numerical modeling, Nesvorny et al. (2008) showed that asteroids can migrate due to Yarkovsky drift and resonances to outside of the boundaries of the Vesta family. We performed photometric observations and determine spins and shapes of V-type objects in Cell I and Cell II in order to characterize the dynamical properties of these asteroids more accurately. The results of dynamical modelling show that some asteroids may have migrated to their current location from the Vesta family within ~2 Gy. There are objects, however, whose origin in another parent body may also be plausible. This may support the hypothesis that the number of differentiated basaltic objects in the inner and middle Main Belt should be much higher than previously assumed. Numerical integration for ~10 asteroids in Cell I and Cell II performed in different variants allowed us to estimate the maximum and average values of Yarkovsky drift that could potentially occur depending on the chosen rotation model.

Asteroid magnitude phase curves from mixed dense and sparse photometry

Emil Wilawer

Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University in Poznan, Poland

We show a method for obtaining phase curves from combined relative (from ground-based observatories) and sparse calibrated data (e.g. originating from Gaia DR2). We validated the method and obtained phase curve parameters for 32 different oppositions of 26 asteroids. In the future, we plan to add more data from various sources to obtain moreprecise phase curves for multiple objects.