Publications

CoLiTec published article in Astronomy & Astrophysics

CoLiTec Team published new article “A method of immediate detection of objects with a near-zero apparent motion in series of CCD-frames” in «Astronomy & Astrophysics» (Impact-factor 5.0).

The paper deals with a computational method for detection of the solar system minor bodies (SSOs), whose inter-frame shifts in series of CCD-frames during the observation are commensurate with the errors in measuring their positions. These objects have velocities of apparent motion between CCD-frames not exceeding three rms errors (3σ) of measurements of their positions. About 15% of objects have a near-zero apparent motion in CCD-frames, including the objects beyond the Jupiter’s orbit as well as the asteroids heading straight to the Earth. The proposed method for detection of the object’s near-zero apparent motion in series of CCD-frames is based on the Fisher f-criterion instead of using the traditional decision rules that are based on the maximum likelihood criterion. We analyzed the quality indicators of detection of the object’s near-zero apparent motion applying statistical and in situ modeling techniques in terms of the conditional probability of the true detection of objects with a near-zero apparent motion. The efficiency of method being implemented as a plugin for the Collection Light Technology (CoLiTec) software for automated asteroids and comets detection has been demonstrated. Among the objects discovered with this plugin, there was the sungrazing comet C/2012 S1 (ISON). Within 26 min of the observation, the comet’s image has been moved by three pixels in a series of four CCD-frames (the velocity of its apparent motion at the moment of discovery was equal to 0.8 pixels per CCD-frame; the image size on the frame was about five pixels). Next verification in observations of asteroids with a near-zero apparent motion conducted with small telescopes has confirmed an efficiency of the method even in bad conditions (strong backlight from the full Moon). So, we recommend applying the proposed method for series of observations with four or more frames.


Use full citation in scientific articles during CoLiTec using:

«Savanevych V. E. A method of immediate detection of objects with a near-zero apparent motion in series of CCD-frames / V. E. Savanevych, S. V. Khlamov, I. B. Vavilova, A. B. Briukhovetskyi, A. V. Pohorelov, D. E. Mkr-tichian, V. I. Kudak, L. K. Pakuliak, E. N. Dikov, R. G. Melnik, V. P. Vlasenko, D. E. Reichart // Astronomy & Astrophysics. – 2018. – Volume 609, A54, 11 p»

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CoLiTec published article in Open European Journal on Variable Stars

CoLiTec Team published new article “FrameSmooth software – new tool for the calibration of astronomical images” in «Open European Journal on Variable Stars», which is included in the science database of NASA – Astrophysics Data System (ADS).

The traditional procedure of image calibration in differential photometry is based on correction for dark-frame and flat-field. This approach don’t remove big scale non-uniformities in the detector illumination caused by Moonlight or other scattered light. This can be corrected by mathematical methods. Ukrainian developers of CoLiTec software use inverse median filter for astrometric tasks. We have tested the possibility to use it for photometry also. The answer is generally positive. There is a chance to skip the flat-field calibration in some cases. We present the FrameSmooth software which performs different image calibration procedures and also able to operate in fully automatic mode.


Use full citation in scientific articles during CoLiTec using:

«Dubovský P. A. FrameSmooth software – new tool for the calibration of astronomical images / P. A. Dubovský, O. B. Bryukhovetskiy, S. V. Khlamov, I. Kudzej, Š. Parimucha, A. V. Pohorelov, V. E. Savanevych, V. P. Vlasenko // Open European Journal on Variable Stars. – 2017. – Vol. 180. – P. 16 – 23»

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CoLiTec published article in Odessa Astronomical Publications

CoLiTec Team published new article “Virtual observatory and CoLiTec software: modules, features, methods” in «Odessa Astronomical Publications» journal, which is included in the science database of NASA – Astrophysics Data System (ADS).

We describe complex processing system created by the CoLiTec project. This system includes features, user-friendly tools for processing control, results reviewing, integration with online catalogs and a lot of different computational modules that are based on the developed methods. Some of them are described in the article.

The main directions of the CoLiTec software development are the Virtual Observatory, software for automated asteroids and comets detection and software for brightness equalization.

The CoLiTec software is widely used in a number of observatories in the CIS. It has been used in about 700 000 observations, during which 1560 asteroids, including 5 NEO, 21 Trojan asteroids of Jupiter, 1 Centaur and four comets were discovered.


Use full citation in scientific articles during CoLiTec using:

«Pohorelov A. V. Virtual observatory and CoLiTec software: modules, features, methods / A. V. Pohorelov, S. V. Khlamov, V. E. Savanevych, A. B. Briukhovetskyi, V. P. Vlasenko // Odessa Astronomical Publications. – Vol. 29 (2016). – P. 136–140. doi: 10.18524/1810-4215.2016.29.85152»

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MONTHLY NOTICES of the Royal Astronomical Society / Instrumentation and Methods for Astrophysics (2015)


A new method based on the subpixel Gaussian model for accurate estimation of asteroid coordinates

V. E. Savanevych, O. B. Briukhovetskyi, N. S. Sokovikova, M. M. Bezkrovny, I. B. Vavilova, Yu. M. Ivashchenko, L. V. Elenin, S. V. Khlamov, Ia. S. Movsesian, A.M. Dashkova, A.V. Pogorelov

Abstract

We describe a new iteration method to estimate asteroid coordinates, which is based on the subpixel Gaussian model of a discrete object image. The method operates by continuous parameters (asteroid coordinates) in a discrete observational space (the set of pixels potential) of the CCD frame. In this model, a kind of the coordinate distribution of the photons hitting a pixel of the CCD frame is known a priori, while the associated parameters are determined from a real digital object image. The developed method, being more flexible in adapting to any form of the object image, has a high measurement accuracy along with a low calculating complexity due to a maximum likelihood procedure, which is implemented to obtain the best fit instead of a least-squares method and Levenberg-Marquardt algorithm for the minimisation of the quadratic form.

Since 2010, the method was tested as the basis of our CoLiTec (Collection Light Technology) software, which has been installed at several observatories of the world with the aim of automatic discoveries of asteroids and comets on a set of CCD frames. As the result, four comets (C/2010 X1 (Elenin), P/2011 NO1(Elenin), C/2012 S1 (ISON), and P/2013 V3 (Nevski)) as well as more than 1500 small Solar System bodies (including five NEOs, 21 Trojan asteroids of Jupiter, and one Centaur object) were discovered. We discuss these results that allowed us to compare the accuracy parameters of a new method and confirm its efficiency.

In 2014, the CoLiTec software was recommended to all members of the Gaia-FUN-SSO network for analysing observations as a tool to detect faint moving objects in frames.

Publication link: http://mnras.oxfordjournals.org/content/451/3/3287

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40th COSPAR Scientific Assembly 2014


Observation of small solar system bodies at the review programs observatory ISON-NM and ISON-Kislovodsk

Savanevych, Vadym; Molotov, Igor; Elenin, Leonid; Bryukhovetskiy, Alexandr; Sokovikova, Nataliia; Nevski, Vitali; Bezkrovniy, Michael; Movsesian, Iana; Khlamov, Sergeii; Dikhtyar, Mykola

Abstract

For the increasing of efficiency of NEA detection and monitoring, it’s necessary to create the automated software for detection of moving objects on series of CCD-frames. To improve observation operativeness, it is necessary to create (develop) software for automated (non-automatic) processing of asteroid survey frames. Presently, CoLiTec software is solving the problem of processing frames of current night asteroid surveys to detect asteroids automatically with subsequent visual confirmation of results. CoLiTec already used in Ukraine (A50) and Russia (H15, D00). CoLiTec helped to detect 4 (C/2011 X1 (Elenin), P/2011 NO1(Elenin), C/2012 S1, P/2013 V3 (Nevski)) out of 7 comets discovered in CIS and Baltic countries within more then 20 recent years. In all, there are about 1500 asteroids discovered due to CoLiTec. Among them, there are 4 out of 16 Earth approaching objects discovered throughout the whole Soviet and post-Soviet CIS and Baltic astronomy history. There are 21 Jupiter Trojans and one of the two centaurs discovered in CIS and Baltic countries. Separate MPC electronic circulars were dedicated to three of the asteroids. During 2011 and 2012 at least 80% observations and 75% preliminary asteroids designations has been done in CIS and Baltic countries. By the overall results of 2011 and 2012, observatory ISON-NM, equipped with a 45-cm telescope and CoLiTec software, ranked 7th worldwide in both number of observations of asteroids and the number of their preliminary discoveries. In 2013, CoLiTec was installed in observatories of Ussuriysk and Krasnodar. More widespread of software among amateur and professional observatories, that use narrow-field and wide-field telescopes, may be started in 2014.

Publication link: http://adsabs.harvard.edu/abs/2014cosp…40E2895S

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Kinematics and Physics of Celestial Bodies


Astroinformation resource of the Ukrainian virtual observatory: Joint observational data archive, scientific tasks, and software

Vavilova, I. B.; Pakulyak, L. K.; Shlyapnikov, A. A.; Protsyuk, Yu. I.; Savanevich, V. E.; Andronov, I. L.; Andruk, V. N.; Kondrashova, N. N.; Baklanov, A. V.; Golovin, A. V.; Fedorov, P. N.; Akhmetov, V. S.; Isak, I. I.; Mazhaev, A. E.; Golovnya, V. V.; Virun, N. V.; Zolotukhina, A. V.; Kazantseva, L. V.; Virnina, N. A.; Breus, V. V.; Kashuba, S. G.; Chinarova, L. L.; Kudashkina, L. S.; Epishev, V. P.

AA(Main Astronomical Observatory NAS of Ukraine; Kyiv, Ukraine irivav@mao.kiev.ua),
AB(Main Astronomical Observatory NAS of Ukraine; Kyiv, Ukraine pakuliak@mao.kiev.ua),
AC(Crimean Astrophysical Observatory; Nauchnyj, Ukraine aas@crao.crimea.ua),
AD(Nikolaev Astronomical Observatory; Nikolaev, Ukraine yuri@mao.nikolaev.ua),
AE(Main Astronomical Observatory NAS of Ukraine; Kyiv, Ukraine domsv1@rambler.ru),
AG(Main Astronomical Observatory NAS of Ukraine; Kyiv, Ukraine andruk@mao.kiev.ua),
AH(Main Astronomical Observatory NAS of Ukraine; Kyiv, Ukraine kondr@mao.kiev.ua),
AJ(Main Astronomical Observatory NAS of Ukraine; Kyiv, Ukraine alex.golovin@gmai.com),
AO(Main Astronomical Observatory NAS of Ukraine; Kyiv, Ukraine goglov@mao.kiev.ua),
AQ(Main Astronomical Observatory NAS of Ukraine; Kyiv, Ukraine nastya@mao.kiev.ua)

Abstract

The overview of the most important components of the national project – Ukrainian Virtual Observatory (UkrVO) – is presented.Among these components, there is the establishment of a Joint Digital Archive (JDA) of observational data obtained at Ukrainian observatories since 1890, including astronegative’s JDA (more than 200 thousand plates). Because of this task requires a VO-oriented software, such issues as software verification of content integrity and JDA administration; compliance of image for mats to IVOA standards; photometric and astrometry calibration of images. Among other developments of local UkrVO software the means of automatic registration of moving celestial objects at the starry sky followed by visual inspection of the results as well as stellar fields image processing software are considered. Research projects that use local UkrVO data archives, namely, an analysis of long observational series of active galactic nuclei, the study of solar flares and solar active regions based on spectral observational archives, research and discovery of variable stars, the study of stellar fields in vicinity gamma-ray bursts are discussed. Particular attention is paid to the CoLiTec program, which allows to increase significantly the number of registered small solar system bodies, and to dis cover new ones, in particular, with the help of this program the comets C/2010 X1 (Elenin) and P/2011 N 01 were discovered in ISON-NM observatory. Development of the UkrVO JDA pro to type is noted which provides access to data bases of MAO NAS of Ukraine, Nikolaev Astronomical Observatory and L’viv Astronomical Observatory.

Publication link: http://adsabs.harvard.edu/abs/2012KPCB…28…85V

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