Athanasopoulos, D. ; Hanuš, J. ; Avdellidou, C. ; van Belle, G. ; Ferrero, A. ; Bonamico, R. ; Gazeas, K. ; Delbo, M. ; Rivet, J. P. ; Apostolovska, G. ; Todorović, N. ; Novakovic, B. ; Bebekovska, E. V. ; Romanyuk, Y. ; Bolin, B. T. ; Zhou,

Eleni Lalounta, Panagiota-Eleftheria Christopoulou, Athanasios Papageorgiou , C. E. Ferreira Lopes, and Márcio Catelan https://doi.org/10.3847/1538-3881/ad4882 August 2024 Abstract Low-mass ratio systems (LMR) are a very interesting class of contact eclipsing binaries challenging the theoretical models of stability. These systems are also considered possible progenitors of

Ramos-Larios G., Guerrero M. A., Toalá J. A., Akras S., Fang X.

Papageorgiou, Athanasios ; Christopoulou, Panagiota-Eleftheria ; Lalounta, Eleni ; Ferreira Lopes, C. E. ; Catelan, Márcio ; Drake, Andrew J. ; Ηantzios, Panayiotis ; Alikakos, Ioannis eprint arXiv:2306.11607 August 2023 Abstract We present a multiband photometric analysis of CRTS J163819.6+03485, the first low-mass-ratio contact binary

Papageorgiou, A., Christopoulou, P.-E., Ferreira Lopes, C. E., Lalounta, E., Catelan, M., Drake, A. J. eprint arXiv:2212.03838 March 2023 Abstract We present the photometric analysis of three ultra-short-period total eclipsing binaries in contact configuration, CRTS_J172718.0+431624, OGLE-BLG-ECL-000104, and OGLE-BLG-ECL-000012, mined from massive astronomical surveys. Using the

Athanasopoulos, D., Hanuš, J., Avdellidou, C., Bonamico, R., Delbo, M., Conjat, M., Ferrero, A., Gazeas, K., Rivet, J. P., Sioulas, N., van Belle, G., Antonini, P., Audejean, M., Behrend, R., Bernasconi, L., Brinsfield, J. W., Brouillard, S., Brunetto, L., Fauvaud, M., Fauvaud, S., Gonzalez, R., Higgins, D., Holoien, T. W.

Loukaidou, G. A. ; Gazeas, K. D. ; Palafouta, S. ; Athanasopoulos, D. ; Zola, S. ; Liakos, A. ; Niarchos, P. G. ; Hakala, P. ; Essam, A. ; Hatzidimitriou, D. eprint arXiv:2112.06631 August 2022 Abstract Ultra-short orbital period contact binaries (Porb < 0.26

Studies on the circumstellar structures around evolved stars provide vital information on the evolution of the parent star and the properties of the local interstellar medium. In this work, we present the discovery and characterization of an optical cocoon tail behind the star HD 185806. The cocoon apex emission is puzzling, as it is detected in the infrared but shows no signal in the optical wavelength.

We present optical ccd images of the large supernova remnant (SNR) G132.7 + 1.3 (HB3) covering its full extent for the first time, in the emission lines of H α+ [N II], [S II] and [O III], where new and known filamentary and diffuse structures are detected. These observations are supplemented by new low-resolution long-slit spectra and higher-resolution images in the same emission lines. Both the flux-calibrated images and spectra confirm that the optical emission originates from shock-heated gas since the [S II]/H α > 0.4.

A stellar occultation by Neptune's main satellite, Triton, was observed on 5 October 2017 from Europe, North Africa, and the USA. We derived 90 light curves from this event, 42 of which yielded a central flash detection. We aimed at constraining Triton's atmospheric structure and the seasonal variations of its atmospheric pressure since the Voyager 2 epoch (1989). We also derived the shape of the lower atmosphere from central flash analysis.