Every day, Earth is bombarded by tiny asteroids and meteoroids, most too small to even be detected. But what if we could study these space rocks by watching their impacts on the Moon? A new ESA project funded under the Horizon Europe programme releases its first observations.
In a rare space-related achievement for Greece, telescopes of the National Observatory of Athens in the Peloponnese are being deployed this summer in an interplanetary laser optical communication experiment, a technology being tested for the first time on European soil, paving the way for the era of the so-called space Internet.
Between July 9 and 12, for the second year in a row, a three-day Summer School of Observational Astrophysics was held in Kryoneri, Corinthia, for graduate and final-year undergraduate students from across Greece. The students were hosted in a local guesthouse, observed the night sky with the 1.2-meter telescope of the Kryoneri Observatory as well as the Sun using a solar telescope and radio antenna, attended lectures, and were trained by Dr. Koulouridis, PhD candidate Ms. Drigga, Dr. Liakos, and Dr. Vardoulaki in techniques of analyzing observational data (optical and radio waves) from the Observatory's researchers. The local community once again warmly supported the School, creating a welcoming and collaborative environment for all. This year's highly successful event followed the first School held in 2023 and confirms that Kryoneri can evolve into a regular meeting point for those who love Astrophysics, with the Observatory at its center.
The updated catalogue of δ Sct stars in binary systems as well as their statistical properties are presented. Thanks to the Kepler, K2 and TESS space missions, this version of the catalogue contains more than 1000 δ Sct pulsators in binaries. The sample is divided according to the Roche Geometry of the binary systems in order to check for any systematic differences in the pulsators' evolution due to the proximity of the companion star. Statistics, demographics, and distributions of these pulsating stars within the H-R and mass-radius diagrams are provided. We notice that the absolute parameters have been accurately determined for only approximately 10% of the whole sample. Additionally, updated correlations between pulsation and orbital periods and evolutionary status are presented. This work aims to motivate the researchers for systematic analyses of such objects in order to increase the sample of systems with well known physical properties.
T CrB is a symbiotic recurrent nova that last erupted in 1946. Given its recurrence time-scale of approximately 80 yr, the next outburst is eagerly anticipated by the astronomical community. In this work, we analyse the optical light curves of T CrB, comparing recent photometric evolution with historical data to evaluate potential predictive indicators of no va eruptions. Although the 'superactive' phases preceding both the 1946 and anticipated eruptions are strikingly similar, the subsequent photometric behaviour differs. We find that the decline in brightness observed in 2023, interpreted by some as a 'pre-eruption dip', deviates from the deep minimum recorded prior to the 1946 event and does not reliably predict the eruption timing. Recent photometric and spectroscopic observations indicate that the system is returning to a high-accretion state. Given this, an eruption may be imminent, even without distinct precursors. While the next eruption of T CrB will be a major scientific event, its expected peak brightness of V ∼2 mag highlights the importance of setting realistic public expectations for what will be a visually modest, yet astrophysically very significant, celestial event.
We present results of the Near-Earth objects Lunar Impacts and Optical TrAnsients (NELIOTA) campaign for lunar impact flashes observed with the 1.2 m Kryoneri telescope. From August 2019 to August 2023, we report 113 validated and 70 suspected flashes. For the validated flashes, we calculate the physical parameters (masses, radii) of the corresponding projectiles, the temperatures developed during the impacts, and the expected crater sizes...
We present the results of a fourth planetary defense exercise, focused this time on the small near-Earth asteroid (NEA) 2023 DZ2 and conducted during its close approach to the Earth in 2023 March. The International Asteroid Warning Network (IAWN), with support from NASA's Planetary Defense Coordination Office (PDCO), has been coordinating planetary defense observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. The last campaign focused on the NEA Apophis, and an outcome of that exercise was the need for a short burst campaign to replicate a real-life near-Earth object impact hazard scenario. The goal of the 2023 DZ2 campaign was to characterize the small NEA as a potential impactor and exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication with a short notice of just 24 hr. The entire campaign lasted about 10 days. The campaign team ...
In the early hours of February 18, 2024 (03:20 AM) a fireball was captured by four different meteor and fireball tracking cameras.
We are pleased to announce the public release of the "Flash Detection Software", which was developed by the National Observatory of Athens for ESA. We invite both amateur or professional astronomers performing planetary observations with video cameras or fast-frame CMOS/CCDs to test it.
The Institute of Astronomy Astrophysics Space Applications & Remote Sensing of the National Observatory of Athens operates Helmos observatory, which was selected as the first Optical Ground Station under the ScyLight framework. Project HOTSPOT (https://artes.esa.int/projects/hotspot) aims to identify all possible activities that can be carried out at Helmos observatory in Greece concerning optical, quantum, and deep space communications.
