Abstract
Context. Transitional objects are minor bodies that share some characteristics with asteroids and others with comets. These objects include asteroids in cometary orbits (ACOs), which behave dynamically like comets, but lack observed activity, while activated asteroids (AAs) follow typical asteroidal orbits, but have shown dust ejections. Aims. The monitoring of a set of these objects carried out in 2015 and 2016 is continued using archival images from various observatories and new data from the IMPACTON telescope in Brazil. Methods. Two techniques were applied to detect activity: (i) surface brightness profiles were compared with those of field stars to identify widening, and (ii) the magnitudes reported in the Minor Planet Center, combined with our observations, were reduced and analyzed to identify abrupt brightness increases as a function of heliocentric distance. Results. We analyzed the surface brightness profiles of 133 ACOs and 7 AAs. To study the reduced magnitude, we obtained data from the 705 ACOs that were known at the time of the analysis. Together with the data from our previous work, our analysis covered 23% of the total known ACOs; 8 deviated slightly in the surface brightness profile, 6 brightened in the reduced magnitude, and one object is in common in both samples. A very low percentage of objects might show activity (4% of the sample with brightness profiles and <1% in the reduced magnitudes). These results would rule out a slow transition from active to inert. Regarding AAs, 4 showed activity, and 3 of them matched previously reported periods, while the data we analyzed for P/2015 X6 were obtained 19 days before the first existing activity report. The activity episodes of these objects are very restricted in time and do not always occur in the same region of the orbit.
| Original language | English |
|---|---|
| Article number | A117 |
| Journal | Astronomy and Astrophysics |
| Volume | 698 |
| DOIs | |
| State | Published - Jun 1 2025 |
Funding
Based on observations collected at the European Southern Observatory under ESO programmes: 60.A-9203(B), 65.S-0184(A), 072.C-0483(B), 079.C-0653(B), 079.C-0670(A), 086.C-0738(A), 095.C-0932(A), 097.C-0912(A), 098.C-0903(B), 099.C-0787(B), 0101.C-0740(A), 167.C-0340(G), 178.C-0036(N), 178.C-0867(G), 178.C-0867(M), 178.C-0867(M), 178.C-0867(T), 278.C-5066(B), 297.C-5060(D), 297.C-5060(E) and 596.C-0822(A). S.M. and G.T. acknowledge financial support from the projects Grupos I+D Ciencias Planetarias C630-348 & C308-347 of the Comisión Sectorial de Investigación Científica (CSIC, Udelar, Uruguay), and the Programa de las Ciencias Básicas (PEDECIBA-MEC, Uruguay). The authors are grateful to the IMPACTON team (T. Rodrigues, R. Souza, A. da Silva, A. Santiago and J. Silva) for the technical support. E.R. would like to thank FAPERJ for its support through a fellowship (E-26/2024.602/2021) and a grant (E-26/201.001/2021). We thank M.E.-S., H.M. and F.W.M. for their observations at OASI in 2019 and 2020. Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovação, the Deutsche Forschungsgemeinschaft and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgenössische Technische Hochschule (ETH) Zürich, Fermi National Accelerator Laboratory, the University of Illinois at Urbana-Champaign, the Institut de Ciències de l’Espai (IEEC/CSIC), the Institut de Física d’Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians-Universität München and the associated Excellence Cluster Universe, the University of Michigan, NSF’s NOIRLab, the University of Nottingham, The Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, Texas A&M University, and the OzDES Membership Consortium. Based in part on observations at Cerro Tololo InterAmerican Observatory at NSF’s NOIRLab (NOIRLab Prop. ID 2012B-0001; PI: J. Frieman), which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. The DES data management system is supported by the National Science Foundation under Grant Numbers AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MICINN under grants ESP2017-89838, PGC2018-094773, PGC2018-102021, SEV-2016-0588, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. Contribution statements: S.M. is lead author, responsible for the development of code, image analysis, and data processing. G.T. had also contributed to the development of code, writing, and editing of the manuscript. The following authors had provided data from different observatories and archival data: M.B-H. and J.C. from DES, E.R. from OASI, and J.L. from IAC. They reviewed the manuscript, and suggested several improvements.
Keywords
- asteroids: general
- comets: general
- minor planets