EPSC Abstracts
Vol. 17, EPSC2024-556, 2024, updated on 03 Jul 2024
https://doi.org/10.5194/epsc2024-556
Europlanet Science Congress 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The small size and high geometric albedo of the Haumea cluster member 1995 SM55 from a stellar occultation and ground based photometry

Jose L. Ortiz1, Nicolas Morales1, Bruno Sicardy2, Estela Fernandez-Valenzuela3, Felipe Braga-Ribas4,5, Juan Luis Rizos1, Mike Kretlow1, José María Gómez-Limón1, Yucel Kilic6, Orhan Erece6, Ibrahim Akoz6, Kadir Uluc6, Shai Kaspi7, Anna Marciniak8, Vlad Turcu9, Dan Moldovan9, Adrian Sonka10, Elisabeta Petrescu10, Alin Nedelcu10, Caglayan Nehir11, and the Lucky Star collaborators and Observers of the 1995SM55 occultation campaing in 2024*
Jose L. Ortiz et al.
  • 1Instituto de Astrofisica de Andalucia-CSIC, Granada, Spain (ortiz@iaa.es)
  • 2LESIA, Observatoire de Paris, Université PSL, Sorbonne Université, Université de Paris, CNRS, 92190 Meudon, France
  • 3FSI, University of Central Florida, Orlando, Florida, USA
  • 4Federal University of Technology - Paraná (PPGFA/UTFPR), Curitiba, PR, Brazil
  • 5Laboratório Interinstitucional de e-Astronomia - LIneA, Rio de Janeiro, RJ, Brazil
  • 6TÜBİTAK National Observatory, Turkey
  • 7Tel Aviv University, Israel
  • 8Astronomical Observatory Institute, Faculty of Physics, A. Mickiewicz University. Poznan, Poland
  • 9Romanian Academy Cluj-Napoca Branch, Astronomical Observatory Cluj-Napoca; Astronomical Institute of the Romanian Academy Romania
  • 10Astronomical Institute of the Romanian Academy Romania
  • 11Astrophysics Research Centre and Observatory, Çanakkale Onsekiz Mart University, Terzioğlu Kampüsü, Çanakkale, Turkey
  • *A full list of authors appears at the end of the abstract

The Trans-Neptunian Object with provisional designation 1995SM55 is one of the few members of the Haumea orbital cluster and therefore it is a very relevant body to study through the occultation technique in order to accurately determine size, shape and geometric albedo.  A very wide campaign involving 50 telescopes was arranged to observe a stellar occultation by this body on 25 February 2024, given that an astrometric update soon before the occultation indicated a good chance of detecting the event. Taking into account that the involved star was relatively bright, at G=12.4 mag, accessible to numerous instruments, the probability of success was high. In the end 7 positive detections from 5 different observatories were obtained and 33 sites obtained negative results. From a preliminary analysis of the occultation results together with ground based photometry data on 1995SM55 that we have gathered over more than a decade with various telescopes, we have been able to determine an accurate projected size and geometric albedo for this object. It turns out that the body is remarkably small for its brightness and therefore it has a high geometric albedo. Given the orbital and spectral similarities of 1995SM55 with Haumea, a high albedo, comparable to that of Haumea and a small size was expected. The final geometric albedo turned out to be even higher than that of Haumea.

Lucky Star collaborators and Observers of the 1995SM55 occultation campaing in 2024:

P. Santos-Sanz, D. Souami, F. Rommel, M. Vara-Lubiano, R. Leiva, R. Vieira-Martins, J. Desmars, R. Duffard, J. Camargo, J. Lecacheux, A. Alvarez-Candal, B. Morgado, M. Assafin, G. Benedetti-Rossi, A. R. Gomes-Júnior, R. Boufleur, M.Acar, O. Schreurs, M. Lecossois, T. Janik, M. N. Bagiran, S. Fisek, S. Alis, F. K. Yelkenci, S. Kalkan, N. Takacs, R. Szakats, A. Pal, J. Manek, D. Bogdan, K. Gazeas, F. Ursache, D. Nardiello, V. Nascimbeni, M.Rottenborn, E. Sonbas, W. Ogłoza, A. Nastasi, S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez, L. Bellizzi, A. Marchini, A.Solmaz, M.Tekeş, D.Antuszewicz, D. Pica, D. Ilic, M. Grozdanovic, U. Hopp, C. Goessl, M. Schmidt, L. Stoian, P. Bacci, M. Maestripieri, M. Krahn, A.Takey, A. E. Abdelaziz, G. Krannich, R. Bacci, M. Altan, K. Hornoch, P. Bacci, M. Maestripieri, R. Nesci, F. Ciabattari, Gy. M. Szabó, J. Kovács, Z. Garai, Z. Bora, P. Zeleny, P. C. Slansky, B. Gaehrken, M. Fiedler, H. Mikuz, A. Mohar, J. Skvarc, L. Curelaru, S. Ion, R. Schaefer, J. Kubánek, P. Delincak

How to cite: Ortiz, J. L., Morales, N., Sicardy, B., Fernandez-Valenzuela, E., Braga-Ribas, F., Rizos, J. L., Kretlow, M., Gómez-Limón, J. M., Kilic, Y., Erece, O., Akoz, I., Uluc, K., Kaspi, S., Marciniak, A., Turcu, V., Moldovan, D., Sonka, A., Petrescu, E., Nedelcu, A., and Nehir, C. and the Lucky Star collaborators and Observers of the 1995SM55 occultation campaing in 2024: The small size and high geometric albedo of the Haumea cluster member 1995 SM55 from a stellar occultation and ground based photometry, Europlanet Science Congress 2024, Berlin, Germany, 8–13 Sep 2024, EPSC2024-556, https://doi.org/10.5194/epsc2024-556, 2024.