HUN-REN-ELTE Astropolarimetry Research Group

Title of research: Construction of a portable imaging-polarimetric astronomical telescope and its applications in regions of the Earth with favourable astroclimate, with special emphasis on the Kordylewski dust clouds.

Grant: HUN-REN-ELTE-0116607 Astropolarimetry Research Group grant application, Hungarian Research Network + Eötvös Loránd University (123 957 438 HUF)

Duration: June 2022 – December 2027 (66 months)

Research topic

Judit Slíz-Balogh, a member of our research group, has succeeded in detecting and recording the polarization patterns of the Kordylewski dust clouds around the triangular Lagrange points L4 and L5 of the Earth-Hold system with a telescope equipped with an imaging polarimeter on 4 occasions between 2017 and 2021 at her private astronomical observatory in Badacsonytördemic. These polarimetric observations have been published in the Monthly Notices of the Royal Astronomical Society [A1, A2, A4] with a great international media echo. Since such nearly one successful observation per year is not suitable to study the visibility and dynamics of these dust clouds, we have applied for a research grant to construct a portable polarization telescope and to perform astronomical measurements with it at favourable astroclimatic locations on Earth.

In the framework of our research programme (starting on 1 July 2022) we built our portable, wide-field-of-view, rotating-linear-analyser, imaging-polarimetric telescope by early 2023. We have found a very favourable astroclimatic site at the Isabis Astrofarm, a private property of Joachim Cranz on the Khomas Highland in Namibia. The excellent astroclimate of this site is demonstrated by the fact that it also hosts the German HESS astronomical station measuring the Chernenkov radiation, a member of the Hungarian HATNET exoplanet observatory telescope system and a Russian space debris observatory.

Our 1st astropolarimetric measurement campaign was conducted from 18 July to 16 August 2023 at the Isabis Astrofarm. One of our results, the polarimetric observation of the Kordylewski dust cloud around the L5 Lagrange point of the Earth-Moon system, was reported in [A6, A7]. Another result of our Namibian measurements from 2023, the detection of a hitherto uncatagolized interstellar cloud, is under publication.

Our 2nd astropolarimetric measurement campaign took place between 18 June and 17 July 2024 at the Isabis Astrofarm. We are writing two papers about our polarization results from this mission.

In addition to our astropolarimetric measurements in Namibia, we are also carrying out computer modelling of the behaviour of the Kordylewski dust clouds and interplanetary dusts and asteroids. In one of our papers [A3], we found a possible explanation why the L5 Kordylewski dust cloud of the Earth-Moon system has been observed three times more frequently than the L4 dust cloud. This could be due to the different particle trapping capabilities of the L4 and L5 Lagrange points. On the basis of our computer simulations, we concluded that the L4 and L5 Lagrange points of the Sun-Jupiter particle system are responsible not only for the formation of the Greek and Trojan asteroid families, but also for the formation of other asteroid families in mean-motion resonance with Jupiter [A5]. We plan to apply this result and study method to the Kordylewski dust clouds, in order to explain the banded structure of these particle formations.

Our astropolarimetric results are published regularly in Hungarian scientific and educational journals [M1-M5], furthermore they are also disseminated in popular-scientific lectures [E1-E15].

In addition to the above, in Namibia we also plan to measure the polarization patterns of the zodiacal light, reflection nebulae and interstellar clouds.

Members

	Gábor Horváth professor, group leader ELTE staff page
	Judit Slíz-Balogh engineer-mathematician, astronomer ELTE staff page
	Attila Mádai mechanical engineer, astronomer ELTE staff page
	Pál Sári mechanical engineer, astronomer external member

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Contacts

English publications

Hungarian publications

Lectures