Issue |
A&A
Volume 664, August 2022
|
|
---|---|---|
Article Number | A130 | |
Number of page(s) | 18 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202141546 | |
Published online | 19 August 2022 |
Physical properties of the trans-Neptunian object (38628) Huya from a multi-chord stellar occultation
1
Instituto de Astrofísica de Andalucía (CSIC),
Glorieta de la Astronomía s/n,
18008 -
Granada, Spain
e-mail: psantos@iaa.es
2
LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Université,
Univ. Paris Diderot,
Sorbonne Paris Cité, France
3
Astronomical Institute of the Romanian Academy,
5 Cuţitul de Argint,
040557
Bucharest, Romania
4
Instituto de Astrofísica de Canarias (IAC), C/Vía Láctea s/n,
38205
La Laguna,
Tenerife, Spain
5
Laboratório Interinstitucional de e-Astronomia – LIneA & INCT do e-Universo,
Rua Gal. José Cristino 77,
Bairro Imperial de São Cristóvão, Rio de Janeiro (RJ), Brazil
6
UNESP – São Paulo State University, Grupo de Dinãmica Orbital e Planetologia,
Guaratinguetá,
SP 12516-410,
Brazil
7
Observatório Nacional/MCTI, Rua Gal.
José Cristino 77,
Bairro Imperial de São Cristóvão, Rio de Janeiro (RJ), Brazil
8
Universidade Federal do Rio de Janeiro – Observatório do Valongo,
Ladeira Pedro Antônio 43,
CEP 20.080-090
Rio de Janeiro, RJ, Brazil
9
Institut Polytechnique des Sciences Avancées IPSA,
63 boulevard de Brandebourg,
94200
Ivry-sur-Seine, France
10
Institut de Mécanique Céleste et de Calcul des Éphémérides, IMCCE, Observatoire de Paris, PLS Research University, CNRS, Sorbonne Universités,
UPMC Univ Paris 06, Univ. Lille, 77 Av. Denfert-Rochereau,
75014
Paris, France
11
Federal University of Technology – Paraná (UTFPR/Curitiba),
Brazil
12
Florida Space Institute, University of Central Florida,
Orlando, FL, USA
13
ISTEK Belde Observatory,
Turkey
14
Department of Astronomy and Space Sciences, University of Ege,
Turkey
15
Faculty of Physics, University of Bucharest,
405, Atomistilor Street,
077125
Magurele, Ilfov, Romania
16
Ataturk University, Astrophysics Research & Application Center (ATASAM),
25240
Erzurum, Turkey
17
Akdeniz University, Faculty of Sciences, Department of Space Sciences and Technologies,
07058
Antalya, Turkey
18
TÜBITAK National Observatory, Akdeniz University Campus,
07058
Antalya, Turkey
19
School of Physics and Astronomy and Wise Observatory, Tel Aviv University,
Israel
20
Department of Astronomy and Space Sciences, Science Faculty, Erciyes University,
38030
Melikgazi, Kayseri, Turkey
21
Particle Physics and Astrophysics Department, Weizmann Institute of Science,
Israel
22
Astronomical Observatory “Amiral Vasile Urseanu”
Bucharest, Romania
23
Space Sciences and Solar Energy Research and Application Center (UZAYMER), Çukurova University,
Adana, Turkey
24
Space Observation and Research Center, Çağ University,
Mersin, Turkey
25
Ege University, Faculty of Science, Department of Physics,
35100
Bornova, Izmir, Turkey
26
Ataturk University, Science Faculty, Department of Astronomy & Space Sciences,
25240
Erzurum, Turkey
27
Astronomical Observatory “Victor Anestin”
Bacau, Romania
28
Astroclubul Bucurefti,
Romania
29
Stardust Observatory,
Brasov, Romania
30
St. George Observatory,
Ploieşti, Romania
31
Ia cu Stele,
Romania
32
Stardreams Observatory,
Valenii de Munte, Romania
33
ROASTERR-1 Observatory,
Cluj-Napoca, Romania
34
Galaţi Astronomical Observatory, “Răsvan Angheluţă” Museum Complex of Natural Sciences,
6A, Regiment 11 Siret Street,
800340,
Galaţi, Romania
35
Tiraspol State University,
5, Ghenadie Iablocikin Street,
2069
Chisinǎu, Republic of Moldova
36
Asociatia Astroclubul Quasar,
Romania
37
Romanian Academy, Cluj-Napoca Branch, Astronomical Observatory Cluj-Napoca,
Str. Cirefilor, Nr. 19,
400487,
Cluj-Napoca, Romania
38
Barlad Observatory,
Romania
39
Institute of Astronomy, V.N. Karazin Kharkiv National University,
Ukraine
40
QOS Observatory, National Space Facilities Control and Test Center,
Ukraine
41
Section of Astrophysics, Astronomy and Mechanics, Department of Physics, National and Kapodistrian University of Athens,
15784
Zografos, Athens, Greece
42
Astronomical Observatory of Odessa I.I. Mechnikov National University,
Shevchenko Park,
Odessa
65014
Ukraine
43
Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH),
1121
Budapest,
Konkoly Thege Miklós út 15–17,
Hungary
44
ELTE Eötvös Loránd University, Institute of Physics,
Budapest
Hungary
45
Çanakkale Onsekiz Mart University, Faculty of Arts and Sciences, Department of Physics,
17020
Çanakkale, Turkey
46
Çanakkale Onsekiz Mart University, Astrophysics Research Center and Ulupinar Observatory,
17020
Çanakkale, Turkey
47
Northolt Branch Observatories,
UK
48
Sainte Marie,
La Réunion, France
49
Agrupació Astronòmica de Sabadell,
Barcelona, Spain
50
International Occultation Timing Association–European Section (IOTA-ES),
Germany
51
Almalex Observatory,
Leeds, UK
52
Les Makes,
La Réunion, France
53
Ellinogermaniki Agogi Observatory,
Athens, Greece
54
Ondokuz Mayis University Observatory, Space Research Center,
55200,
Kurupelit, Samsun, Turkey
55
Laboratory of Space Researches, Uzhhorod National University,
Uzhhorod, Daleka Str., 2A,
Uzhhorod,
88000,
Ukraine
56
Astronomical Observatory Institute, Faculty of Physics, A. Mickiewicz University,
Sloneczna 36,,
60-286
Poznań, Poland
57
Mt. Suhora Observatory, Pedagogical University, ul.
Podchorazych 2,
PL-30-084
Krakow, Poland
58
Department of Physics, Faculty of Science and Arts, Inönü University,
Malatya, Turkey
59
Astronomical Observatory, Institute of Theoretical Physics and Astronomy, Vilnius University,
Sauletekio av. 3,
10257
Vilnius, Lithuania
60
Janusz Gil Institute of Astronomy, University of Zielona Góra,
Prof. Szafrana 2,
PL-65-516
Zielona Góra, Poland
Received:
14
June
2021
Accepted:
30
April
2022
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 (mG = 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° ± 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 (pV = 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 psurf = 10 nbar.
Key words: Kuiper belt objects: individual: Huya / methods: observational / techniques: photometric
© P. Santos-Sanz et al. 2022
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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