Guhl Konrad: To Sardinia with the M2
Following the observation of the stellar occultation by Neptune in 2024, improvements to the M2 telescope were planned. The improvements to the finder and the power supply were tested for the first time during the expedition to Sardinia to observe the stellar occultation by Didymos on 16 April 2026. The individual changes are outlined, and the positive results of the observation are presented.
Kattentidt Björn: Video Astronomy using Smart Telescopes?
Occultation of (5368) Vitagliano at 12.03.2026
Improved predictions of stellar occultations based on Gaia DR3 lead to more positive observations using a single chord only. Multiple chords are significantly more valuable. The methods and instruments, as well as their specific features, are examined. It is difficult to find such occultation predictions in the vicinity using OccultWatcher. A method for filtering events more easily is described. Three Seestar S50s were used. A solution for timestamps has been found and is presented !
DAMIT models are used to classify the observations.
OConnell Michael: “First year of observations from a remote observatory”
BABA AISSA Djounai: “Coordinated Dual-Station Positive Detection of a Stellar Occultation by Near-Earth Asteroid (4055) Magellan in Southern Algeria”
Stellar occultations by near-Earth asteroids provide a powerful method to constrain their size, shape, and astrometric position with high precision. We report a coordinated dual station positive detection of a stellar occultation by the near-Earth asteroid (4055) Magellan observed from southern Algeria, near the city of Laghouat. The event was successfully recorded from two sites using Watec CCD-based imaging systems with precise time insertion.
Both stations yielded positive chords, allowing the reconstruction of a double-chord profile of the asteroid silhouette. The measured occultation durations, on the order of 0.2 seconds at both stations, are consistent with a projected size of approximately 2.7 km. These measurements suggest a possibly elongated shape, which will be further investigated through future observations. Despite the limited number of observing stations, the results demonstrate the scientific value of coordinated observations in underrepresented regions.
This work reflects the growing involvement of the Algiers Observatory in the study and observation of stellar occultations by near-Earth asteroids and highlights the increasing contribution of North African observers to global stellar occultation campaigns.
Schweizer Andreas: DVTI+CAM project update
I would like to present the progress and planned evolution of the DVTI+CAM camera and software (test results with new image sensors etc.), duration 45 minutes. I’ll provide a more detailed abstract in the coming days.
De Groot Henk: The “”Good”” project.
The DOA (Dutch Occultation Association) was asked to collaborate on the “GOOD” project by providing occultation data. Since all European data are processed within SODIS, the IOTA-ES board was asked to participate, and they responded positively.
The “GOOD” project aims to create a platform featuring fully open- source software capable of performing orbit calculations for all solar system objects. It integrates two existing software packages: one that performs the calculations and another that handles data management. The project is being carried out by Delft University of Technology and the University of Groningen.”
Abdelkader Hammadi, Lazhari Saci: Constraints from Two Stellar Occultations Observed in a Single Night from Massaad in Algeria
As part of a citizen science program dedicated to asteroid stellar occultations, developed in Algeria since 2016, a joint observational campaign involving both professional and amateur astronomers was conducted on the night of October 02-03, 2025. The primary objective was to observe two successive stellar occultations caused by the near-Earth asteroid (2100) Ra Shalom and the main-belt asteroid (16) Psyche.
Members of the Suhail Astronomy Association of Laghouat made a significant contribution to this dual campaign through both manpower and instrumentation. The observing site was selected near Massaad in the southern of Algeria, where the predicted occultation paths intersected, enabling the potential simultaneous observation of both events.
Three observing stations were deployed, each equipped with three telescopes. Our team operated two motorized Celestron EdgeHD 8 telescopes, coupled with Watec video cameras and IOTA VTI time inserters. The third instrument, a motorized Celestron 9.25 telescope provided by Al-Biruni Astronomy Association of Algiers, was equipped with a similar setup.
Scientific supervision throughout the campaign was ensured by researchers from the CRAAG Research Center.
The overall results were mixed due to technical failures. Only one exploitable dataset was obtained during the occultation by asteroid (2100) Ra-Shalom; however, the event resulted in a negative detection at station 2, while observations at stations 1 and 3 were compromised by technical issues.
Despite these limitations, the campaign provided valuable experience in coordinating simultaneous multi-station observations. Ongoing collaboration with the CRAAG Research Center, incorporating IOTA data, is expected to enhance the preparation and execution of future scientifically relevant occultation campaigns.
Bernd Gährken: Eclipsing Moons at Minor Planets
Currently, about a dozen minor planets with moons are known whose eclipses produce an amplitude that is easily measurable for amateur astronomers.
The presentation will present some examples and show results from the binary asteroid 90 Antiope.
Bernd Gährken: Venus occultation of a 4.6 mag star at 1988
On May 11, 1988, a rare occultation of a bright star by the planet Venus occurred. Video astronomy was still in its infancy at the time, and very few recordings are known. One exception is a video by Mr. Denzau, recorded with a Philips VK4053 camera on a C14 telescope.
This short presentation demonstrates an attempt of an photometric analysis.
Lallemand Raphaël: Summary of Pro/Am Collaboration on Binary Asteroids Stellar Occultations – Gaiamoons
Andersson Sven: SODIS – collecting observations for 3 years
Purvinskis Robert: More about scintillation and occultations
Following a recent presentation at the Stuttgart ESOP meeting, a proposed method for improving signal-to-noise levels for bright stars, using multiple small apertures, was suggested. Simulations and first test results will be presented.
Patrick Martinez: A vintage trainer for the occultations
40 years ago, when occultations were observed visually and measured with a chronometer, I designed this hardware system to train observers and measure their reaction time. Just a museum piece to be presented.”
Thierry Midavaine: 2026 PheMu Campaign : Eclipses of Amalthea and Thebe call for observations.
Jean-Eudes Arlot LTE Observatoire de Paris, Thierry Midavaine Club Eclipse SAF and Michael Irzyk TJMS Observatory SAF.
The PHEMU campaigns is one of the oldest ProAm periodic campaign proposed to
the worldwide amateur community. About every 5 years, occultations and eclipses between the Galilean satellites provide very easy events to catch with small telescopes. Same synchronized phenomena could be observed from the Earth side able to look at Jupiter. It allowed to improve the ephemerides of these satellites which was the targets of space probes. These ephemerides meet now high accuracies thanks to these space missions or exceptional star occultations. Small inner Jupiter satellites could be the target of amateurs to improve their respective ephemerids. It will allow to bring constraints on the radial density distribution inside Jupiter. These events are more difficult to catch. However previous recordings and trials performed with new sensitive digital cameras demonstrate selected
events are now in the range of amateur abilities.
This paper is introducing the 2026 – 2027 campaign to the amateur community able to deal with telescope availability, longitudes and weather constraints. In the coming year, amateurs have dates with the best eclipses of Amalthea and Thebe closed to the Jupiter quadratures. Paris Observatory LTE is waiting for your accurately time stamped light curves !”
Wojciech Burzyński: Search for asteroid moons
The search for asteroid moons is a significant area of research in modern planetary science, providing key insights into the formation and evolution of small bodies in the Solar System. The talk presents an overview of methods for detecting natural asteroid satellites. Particular attention is paid to occultation and photometric techniques also radar, and high-resolution observations using ground-based and space-based telescopes.”
Pratt Alex: Lunar Impact Flashes (LIFs) – take part in the LUMIO mission to monitor meteoroid impacts on the Moon
Why is this of interest to occultation observers? The equipment we use to make accurate timings of occultation events can also record the brief flash (< 1s) of a meteoroid strike on the Moon.
This presentation summarises the recent successful LIF campaigns to monitor impacts during the Geminid and Lyrid meteor showers. How to record them and how to submit observations to the LIF website.
Aims: – to estimate the meteoroid flux in cislunar space and to prepare teams of observers to take part in the Italian/ESA LUMIO mission in 2028. LUMIO (Lunar Meteoroid Impacts Observer) is a CubeSat which will be placed in an Earth-Moon L2 halo orbit to detect impact flashes on the lunar far side.
Tanguy Chope: Towards a Community Standard for Stellar Occultation Results: an EPN-TAP Extension and Prototype Service
Tanguy Chope (1), Damya Souami (1,2), Stephane Erard (1), Renaud Savalle (3)
(1) LIRA, CNRS UMR8254, Observatoire de Paris, Universite PSL, Sorbonne Universite,
Universite Paris Cite, CY Cergy Paris Universite, Meudon, France
(2) naXys, Department of Mathematics, University of Namur, Belgium
(3) DIO/PADC, Observatoire de Paris, Universite PSL, Meudon, France
Stellar occultations, the passage of a Solar System body in front of a background star, are recorded every week by professional and amateur networks worldwide. Amateur observers provide a large share of the chords behind the field’s landmark results: the rings of Chariklo,
Haumea and Quaoar; the atmospheres of Pluto and Triton, monitored over decades; the discovery of Varda’s satellite Ilmarë. Once published, these results remain scattered across individual papers, in inconsistent formats, units and conventions. There is no shared repository and no way to query, for instance, all bodies with a confirmed ring detection, or the evolution of Triton’s surface pressure across every campaign since 1989, without an extensive literature search. Gaia DR4 (expected late 2026) and the Vera C. Rubin Observatory will substantially increase the number of predictable and observable events, which will make this fragmentation more limiting.
The Virtual Observatory (VO) provides an established framework for this kind of problem: an international set of open protocols allowing any archive to be queried through the same tools. Solar System data already has a dedicated VO protocol, EPN-TAP (the Europlanet Table Access Protocol) [1,2], the standard used by the VESPA infrastructure to publish and query planetary datasets across Europe and beyond. We propose an extension to EPN-TAP that adds a small set of occultation-specific fields, covering the event itself (epoch, shadow velocity, occulted-star and occulting-body parameters), the derived physical results (equivalent diameter, oblateness, geometric albedo), secondary detections (rings, atmospheres, satellites, central flashes), and, at the finest granularity, one entry per observing station linked to its normalised light curve for independent reanalysis.
This design is validated by a prototype service, occ_test, built from four events selected to cover each category of the extension: the two rings of (50000) Quaoar (2022) [4], Triton’s atmosphere (occultations from 1989 to 2017) [3], the shape of (174567) Varda and its satellite Ilmarë (2018) [5], and Neptune’s atmosphere (2021) [6]. The service is queried like any astronomical catalogue, using a standard query language, from tools such as TOPCAT; each entry links to authoritative external records (star and body identification, orbital and physical parameters) rather than duplicating them. occ_test is a proof of concept and does not affect how observations are conducted, reduced, or fitted; it concerns only the publication and discovery of results once they are ready to be shared. We present this work at ESOP to gather feedback from the community on the proposed fields, on the practicalities of contributing results to the database, and on the aspects of the design that remain to be refined.
References:
[1] Erard S. et al. 2018, Planetary and Space Science, 150, 65-85.
[2] Erard S. et al. 2022, EPN-TAP: Publishing Solar System Data to the Virtual Observatory,
v2.0, IVOA Recommendation, https://ivoa.net/documents/EPNTAP.
[3] Marques Oliveira J. et al. 2022, Astronomy & Astrophysics, 659, A136.
[4] Pereira C. L. et al. 2023, Astronomy & Astrophysics, 673, L4.
[5] Souami D. et al. 2020, Astronomy & Astrophysics, 643, A125.
[6] Rolland L. 2024, Master’s internship report, Observatoire de Paris.
Damya Souami: Prospects for Pro-Am collaborations in the framework of Asteroids2029 (the International Year of Asteroid Awareness and Planetary Defence)
Asteroids2029 builds towards a rare and historic celestial event: on 13 April 2029, the asteroid (99942) Apophis will skim closer to Earth than some satellites – close enough for billions of people to potentially see it – with a naked eye- in the night sky. This encounter constitutes a once in a few millennia opportunity. While space agencies, industry, and academics are preparing for this historic encounter — through the RAMSES(ESA-JAXA) and OSIRIS-APEX(NASA) missions, I will present here the prospects for ProAm collaborations to support this global effort.
Richard Nolthenius: The Discovery of a 2nd Moon of Quaoar by Occultation
Discovery on June 25, 2025 of a second moon ~30km in size, orbiting Quaoar at the Monterey Institute for Research in Astronomy Oliver Observing Station in the Big Sur mountains of California, by Nolthenius, Bender, Cotton, et al.
Posters:
| Name | Title | Abstract |
|---|---|---|
| E. Velasco (IOTA & AAM) and P. Laurent (SAF) | Double-star lunar occultations: Latest results from the OLED project | A summary of the results of the OLED project in the last year will be presented. |