Artículos de revistas
Physical properties of the trans-Neptunian object (38628) Huya from a multi-chord stellar occultation
Fecha
2022-08-19Registro en:
Astronomy & Astrophysics. Les Ulis Cedex A: Edp Sciences S A, v. 664, 18 p., 2022.
0004-6361
10.1051/0004-6361/202141546
WOS:000841954000001
Autor
Inst Astrofis Andalucia CSIC
Sorbonne Univ
Romanian Acad
Inst Astrofis Canarias IAC
Lab Interinst E Astron LIneA
INCT E Universo
Universidade Estadual Paulista (UNESP)
Observ Nacl MCTI
Universidade Federal do Rio de Janeiro (UFRJ)
Inst Polytech Sci
UPMC Univ Paris 06
Fed Univ Technol Parana UTFPR Curitiba
Univ Cent Florida
ISTEK Belde Observ
Univ Ege
Univ Bucharest
Ataturk Univ
Akdeniz Univ
TUBITAK Natl Observ
Tel Aviv Univ
Erciyes Univ
Weizmann Inst Sci
Astron Observ Amiral Vasile Urseanu Bucharest
Cukurova Univ
Ege Univ
Astron Observ Victor Anestin Bacau
Astroclubul Bucuresti
Stardust Observ
St George Observ
Ia Cu Stele
Stardreams Observ
ROASTERR 1 Observ
Galati Astron Observ
Tiraspol State Univ
Asociatia Astroclubul Quasar
Barlad Observ
Kharkov Natl Univ
Natl Space Facil Control & Test Ctr
Natl & Kapodistrian Univ Athens
II Mechnikov Natl Univ
Eotvos Lorand Res Network ELKH
Eotvos Lorand Univ
Canakkale Onsekiz Mart Univ
Ulupinar Observ
Northolt Branch Observ
Agrupacio Astron Sabadell
Int Occultat Timing Assoc European Sect IOTA ES
Almalex Observ
Ellinogermaniki Agogi Observ
Ondokuz Mayis Univ Observ
Uzhgorod Natl Univ
Adam Mickiewicz Univ
Pedag Univ
Inonu Univ
Vilnius Univ
Univ Zielona Gora
Institución
Resumen
Context. As part of our international program aimed at obtaining accurate physical properties of trans-Neptunian objects (TNOs), we predicted a stellar occultation by the TNO (38628) Huya of the star Gaia DR2 4352760586390566400 (m(G) = 11.5 mag) on March 18, 2019. After an extensive observational campaign geared at obtaining the astrometric data, we updated the prediction and found it favorable to central Europe. Therefore, we mobilized half a hundred of professional and amateur astronomers in this region and the occultation was finally detected by 21 telescopes located at 18 sites in Europe and Asia. This places the Huya event among the best ever observed stellar occultation by a TNO in terms of the number of chords. Aims. The aim of our work is to determine an accurate size, shape, and geometric albedo for the TNO (38628) Huya by using the observations obtained from a multi-chord stellar occultation. We also aim to provide constraints on the density and other internal properties of this TNO. Methods. The 21 positive detections of the occultation by Huya allowed us to obtain well-separated chords which permitted us to fit an ellipse for the limb of the body at the moment of the occultation (i.e., the instantaneous limb) with kilometric accuracy. Results. The projected semi-major and minor axes of the best ellipse fit obtained using the occultation data are (a ', b ') = (217.6 +/- 3.5 km, 194.1 +/- 6.1 km) with a position angle for the minor axis of P ' = 55.2 degrees +/- 9.1. From this fit, the projected area-equivalent diameter is 411.0 +/- 7.3 km. This diameter is compatible with the equivalent diameter for Huya obtained from radiometric techniques (D = 406 +/- 16 km). From this instantaneous limb, we obtained the geometric albedo for Huya (p(V) = 0.079 +/- 0.004) and we explored possible three-dimensional shapes and constraints to the mass density for this TNO. We did not detect the satellite of Huya through this occultation, but the presence of rings or debris around Huya was constrained using the occultation data. We also derived an upper limit for a putative Pluto-like global atmosphere of about p(surf) = 10 nbar.