Hint of an exocomet transit in the CHEOPS light curve of HD 172555
- Author(s)
- F. Kiefer, V. Van Grootel, A. Lecavelier Des Etangs, Gy M. Szabó, A. Brandeker, C. Broeg, A. Collier Cameron, A. Deline, G. Olofsson, T. G. Wilson, S. G. Sousa, D. Gandolfi, G. Hébrard, Y. Alibert, R. Alonso, G. Anglada, T. Bárczy, D. Barrado, S. C.C. Barros, W. Baumjohann, M. Beck, T. Beck, W. Benz, N. Billot, X. Bonfils, J. Cabrera, S. Charnoz, Sz Csizmadia, M. B. Davies, M. Deleuil, L. Delrez, O. D.S. Demangeon, B. O. Demory, D. Ehrenreich, A. Erikson, A. Fortier, L. Fossati, M. Fridlund, M. Gillon, M. Güdel, K. Heng, S. Hoyer, K. G. Isaak, L. L. Kiss, J. Laskar, M. Lendl, C. Lovis, D. Magrin, P. F.L. Maxted, M. Munari, V. Nascimbeni, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, D. Piazza, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, F. Ratti, H. Rauer, C. Reimers, I. Ribas, N. C. Santos, G. Scandariato, D. Ségransan, A. E. Simon, A. M.S. Smith, M. Steller, N. Thomas, S. Udry, I. Walter, N. A. Walton
- Abstract
HD 172555 is a young (∼20 Myr) A7V star surrounded by a 10 au wide debris disk suspected to be replenished partly by collisions between large planetesimals. Small evaporating transiting bodies, that is exocomets, have also been detected in this system by spectroscopy. After β Pictoris, this is another example of a system possibly witnessing a phase of the heavy bombardment of planetesimals. In such a system, small bodies trace dynamical evolution processes. We aim to constrain their dust content by using transit photometry. We performed a 2-day-long photometric monitoring of HD 172555 with the CHEOPS space telescope in order to detect shallow transits of exocomets with a typical expected duration of a few hours. The large oscillations in the light curve indicate that HD 172555 is a δ Scuti pulsating star. After removing those dominating oscillations, we found a hint of a transient absorption. If fitted with an exocomet transit model, it would correspond to an evaporating body passing near the star at a distance of 6.8±1.4R∗ (or 0.05±0.01 au) with a radius of 2.5 km. These properties are comparable to those of the exocomets already found in this system using spectroscopy, as well as those found in the β Pic system. The nuclei of the Solar System's Jupiter family comets, with radii of 2-6 km, are also comparable in size. This is the first piece of evidence of an exocomet photometric transit detection in the young system of HD 172555.
- Organisation(s)
- Department of Astrophysics, Campus Information & Business Intelligence Services
- External organisation(s)
- Université Paris VI - Pierre-et-Marie-Curie, Université de recherche Paris Sciences et Lettres, Université de Liège, Eötvös Loránd University Budapest, Stockholm University, Universität Bern, University of St. Andrews, Université de Genève, Universidade do Porto, Università degli Studi di Torino, Observatoire de Haute-Provence, Institute of Astrophysics of the Canary Islands, University of La Laguna, Universitat Autònoma de Barcelona , Spanish National Research Council (CSIC), Institute of Space Studies of Catalonia (IEEC), Admatis Ltd., European Space Astronomy Centre (ESA), Österreichische Akademie der Wissenschaften (ÖAW), University of Grenoble Alpes, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Université de Paris, Lund University, Aix-Marseille Université, Leiden University, Chalmers University of Technology, University of Warwick, Science and Operations Department - Science Division (SCI-SC), Eötvös Loránd Research Network, Osservatorio Astronomico, Keele University, INAF-Osservatorio Astrofisico di Catania, University of Padova, Eidgenössische Technische Hochschule Zürich, University of Cambridge, Technische Universität Berlin, Freie Universität Berlin (FU)
- Journal
- Astronomy and Astrophysics
- Volume
- 671
- No. of pages
- 12
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/202245104
- Publication date
- 03-2023
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics, 103038 Space exploration
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/f7ff9cae-f33f-4f56-ad01-0400a0162b0f