Size and Shape Constraints of (486958) Arrokoth from Stellar Occultations
Abstract
We present the results from four stellar occultations by (486958) Arrokoth, the flyby target of the New Horizons extended mission. Three of the four efforts led to positive detections of the body, and all constrained the presence of rings and other debris, finding none. Twenty-five mobile stations were deployed for 2017 June 3 and augmented by fixed telescopes. There were no positive detections from this effort. The event on 2017 July 10 was observed by SOFIA with one very short chord. Twenty-four deployed stations on 2017 July 17 resulted in five chords that clearly showed a complicated shape consistent with a contact binary with rough dimensions of 20 by 30 km for the overall outline. A visible albedo of 10% was derived from these data. Twenty-two systems were deployed for the fourth event on 2018 Aug 4 and resulted in two chords. The combination of the occultation data and the flyby results provides a significant refinement of the rotation period, now estimated to be 15.9380 0.0005 hours. The occultation data also provided high-precision astrometric constraints on the position of the object that were crucial for supporting the navigation for the New Horizons flyby. This work demonstrates an effective method for obtaining detailed size and shape information and probing for rings and dust on distant Kuiper Belt objects as well as being an important source of positional data that can aid in spacecraft navigation that is particularly useful for small and distant bodies.
Keywords
Cite
@article{arxiv.2001.00125,
title = {Size and Shape Constraints of (486958) Arrokoth from Stellar Occultations},
author = {Marc W. Buie and Simon B. Porter and Peter Tamblyn and Dirk Terrell and Alex Harrison Parker and David Baratoux and Maram Kaire and Rodrigo Leiva and Anne J. Verbiscer and Amanda M. Zangari and François Colas and Baïdy Demba Diop and Joseph I. Samaniego and Lawrence H. Wasserman and Susan D. Benecchi and Amir Caspi and Stephen Gwyn and J. J. Kavelaars and Adriana C. Ocampo Uría and Jorge Rabassa and M. F. Skrutskie and Alejandro Soto and Paolo Tanga and Eliot F. Young and S. Alan Stern and Bridget C. Andersen and Mauricio E. Arango Pérez and Anicia Arredondo and Rodolfo Alfredo Artola and Abdoulaye Bâ and Romuald Ballet and Ted Blank and Cheikh Tidiane Bop and Amanda S. Bosh and Matías Aarón Camino López and Christian M. Carter and J. H. Castro-Chacón and Alfonso Caycedo Desprez and Nicolás Caycedo Guerra and Steven J. Conard and Jean-Luc Dauvergne and Bryan Dean and Michelle Dean and Josselin Desmars and Abdou Lahat Dieng and Mame Diarra Bousso Dieng and Omar Diouf and Gualbert Séraphin Dorego and David W. Dunham and Joan Dunham and Hugo A. Durantini Luca and Patrick Edwards and Nicolas Erasmus and Gayane Faye and Mactar Faye and Lucas Ezequiel Ferrario and Chelsea L. Ferrell and Tiffany J. Finley and Wesley C. Fraser and Alison J. Friedli and Julián Galvez Serna and Esteban A. Garcia-Migani and Anja Genade and Kai Getrost and Ricardo A. Gil-Hutton and German N. Gimeno and Eli Joseph Golub and Giovanni Francisco González Murillo and Michael D. Grusin and Sebastian Gurovich and William H. Hanna and Santiago M. Henn and P. C. Hinton and Paul J. Hughes and John David Josephs and Raul Joya and Joshua A. Kammer and Brian A. Keeney and John M. Keller and Emily A. Kramer and Stephen E. Levine and Carey M. Lisse and Amy J. Lovell and Jason A. Mackie and Stanislav Makarchuk and Luis E. Manzano and Salma Sylla Mbaye and Modou Mbaye and Raul Roberto Melia and Freddy Moreno and Sean K. Moss and Diene Ndaiye and Mapathe Ndiaye and Matthew J. Nelson and Catherine B. Olkin and Aart M. Olsen and Victor Jonathan Ospina Moreno and Jay M. Pasachoff and Mariana Belen Pereyra and Michael J. Person and Giovanni Pinzón and Eduardo Alejandro Pulver and Edwin A. Quintero and Jeffrey R. Regester and Aaron Caleb Resnick and Mauricio Reyes-Ruiz and Alex D. Rolfsmeier and Trina R. Ruhland and Julien Salmon and Pablo Santos-Sanz and Marcos Ariel Santucho and Diana Karina Sepúlveda Niño and Amanda A. Sickafoose and José S. Silva and Kelsi N. Singer and Joy N. Skipper and Stephen M. Slivan and Rose J. C. Smith and Julio C. Spagnotto and Andrew W. Stephens and Samuel D. Strabala and Francisco J. Tamayo and Henry B. Throop and Andrés David Torres Cañas and Labaly Toure and Alassane Traore and Constantine C. C. Tsang and Jake D. Turner and Santiago Vanegas and Roger Venable and John C. Wilson and Carlos A. Zuluaga and Jorge I. Zuluaga},
journal= {arXiv preprint arXiv:2001.00125},
year = {2020}
}
Comments
Submitted to Astronomical Journal (revised); 40 pages, 13 figures, 9 tables