Four new binary minor planets: (854) Frostia, (1089) Tama, (1313) Berna, (4492) Debussy
Raoul Behrend
(1)
,
L. Bernasconi
(2, 3)
,
R. Roy
(2, 4)
,
Alain Klotz
(5, 6)
,
François Colas
(7, 2)
,
P. Antonini
(2, 8)
,
R. Aoun
(9)
,
K. Augustesen
(10)
,
E. Barbotin
(9)
,
N. Berger
(11)
,
H. Berrouachdi
(12)
,
E. Brochard
(2)
,
A. Cazenave
(9)
,
C. Cavadore
(2)
,
J. Coloma
(13)
,
V. Cotrez
(9)
,
S. Deconihout
(2)
,
C. Demeautis
(2)
,
J. Dorseuil
(12)
,
G. Dubos
(9)
,
R. Durkee
(14)
,
Eric Frappa
(15)
,
Felix Hormuth
(16)
,
T. Itkonen
(17)
,
C. Jacques
(18)
,
L. Kurtze
(19)
,
A. Laffont
(9)
,
M. Lavayssière
(2)
,
Jean Lecacheux
(20, 21, 22)
,
A. Leroy
(9)
,
F. Manzini
(23)
,
G. Masi
(24)
,
D. Matter
(2)
,
R. Michelsen
(25)
,
J. Nomen
(26)
,
A. Oksanen
(27)
,
P. Pääkkönen
(17)
,
André Peyrot
(12)
,
E. Pimentel
(18)
,
D. P. Pray
(28)
,
Claudine Rinner
(2)
,
S. Sanchez
(26)
,
K. Sonnenberg
(29)
,
Stefano Sposetti
(30)
,
D. Starkey
(31)
,
R. Stoss
(26)
,
Jean-Paul Teng
(12)
,
M. Vignand
(12)
,
N. Waelchli
(32)
1
ObsGE -
Observatoire Astronomique de l'Université de Genève
2 AUDE - Association des Utilisateurs de Détecteurs Electroniques
3 Observatoire des Engarouines
4 Observatoire de Blauvac
5 CESR - Centre d'étude spatiale des rayonnements
6 OHP - Observatoire de Haute-Provence
7 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
8 Observatoire de Bédoin
9 Association T60, Observatoire Midi-Pyrénées
10 Astronomical Observatory, NBIfAFG
11 Observatoire de St-Jean de Bournay
12 Observatoire astronomique des Makes
13 Agrupación Astronómica de Sabadell
14 Shed of Science Observatory
15 Planétarium de Saint-Etienne
16 MPIA - Max-Planck-Institut für Astronomie
17 Helsingin yliopisto = Helsingfors universitet = University of Helsinki
18 CEAMIG - Centro de Estudos Astronômicos de Minas Gerais
19 Darmstadt University of Technology
20 Observatoire de Paris
21 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
22 Pôle Planétologie du LESIA
23 Stazzione Astronomica di Sozzago
24 Università degli Studi di Roma Tor Vergata [Roma, Italia] = University of Rome Tor Vergata [Rome, Italy] = Université de Rome Tor Vergata [Rome, Italie]
25 DTU - Danmarks Tekniske Universitet = Technical University of Denmark
26 Observatori Astronómico de Mallorca, Camí de l'Observatori
27 NYTT - Nyrölä Observatory
28 Carbuncle Hill Observatory
29 Sternwarte Weinheim
30 Observatorio di Gnosca
31 DeKalb Observatory
32 Observatoire François-Xavier Bagnoud
2 AUDE - Association des Utilisateurs de Détecteurs Electroniques
3 Observatoire des Engarouines
4 Observatoire de Blauvac
5 CESR - Centre d'étude spatiale des rayonnements
6 OHP - Observatoire de Haute-Provence
7 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
8 Observatoire de Bédoin
9 Association T60, Observatoire Midi-Pyrénées
10 Astronomical Observatory, NBIfAFG
11 Observatoire de St-Jean de Bournay
12 Observatoire astronomique des Makes
13 Agrupación Astronómica de Sabadell
14 Shed of Science Observatory
15 Planétarium de Saint-Etienne
16 MPIA - Max-Planck-Institut für Astronomie
17 Helsingin yliopisto = Helsingfors universitet = University of Helsinki
18 CEAMIG - Centro de Estudos Astronômicos de Minas Gerais
19 Darmstadt University of Technology
20 Observatoire de Paris
21 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
22 Pôle Planétologie du LESIA
23 Stazzione Astronomica di Sozzago
24 Università degli Studi di Roma Tor Vergata [Roma, Italia] = University of Rome Tor Vergata [Rome, Italy] = Université de Rome Tor Vergata [Rome, Italie]
25 DTU - Danmarks Tekniske Universitet = Technical University of Denmark
26 Observatori Astronómico de Mallorca, Camí de l'Observatori
27 NYTT - Nyrölä Observatory
28 Carbuncle Hill Observatory
29 Sternwarte Weinheim
30 Observatorio di Gnosca
31 DeKalb Observatory
32 Observatoire François-Xavier Bagnoud
Résumé
Context.
Aims.We present evidence that four minor planets of the main belt are binary systems.
Methods.These discoveries are based on CCD photometric measurements made by many observers coordinated in a network of observatories.
Results.Orbital and physical properties are derived from a total of 134 partial light curves involving 26 stations. (854) Frostia, (1089) Tama, (1313) Berna, and (4492) Debussy show mutual eclipses features on their light curves. In all cases, rotation and revolution are synchronous. Synodic periods are 37.728, 16.444, 25.464 and 26.606 h respectively. From a simple model, we have derived their bulk densities as follows: 0.89 ± 0.14, 2.52 ± 0.30, 1.22 ± 0.15 and 0.91 ± 0.10 g cm-3 respectively. Uncertainties in the bulk densities, arising from scattering and shadow effects are not taken into account. These could increase the density estimates by a factor up to 1.6. Our method of determining bulk density is completely independent of their mass and their diameter estimates. The low rotational periods and the low bulk densities clearly imply a collisional process to explain this kind of binary asteroid. Based on our database of a few thousand light curves of minor planets, the population of similar-sized objects in the main belt is estimated to 6± 3 percent in the 10-50 km diameter class.
Conclusions.
Aims.We present evidence that four minor planets of the main belt are binary systems.
Methods.These discoveries are based on CCD photometric measurements made by many observers coordinated in a network of observatories.
Results.Orbital and physical properties are derived from a total of 134 partial light curves involving 26 stations. (854) Frostia, (1089) Tama, (1313) Berna, and (4492) Debussy show mutual eclipses features on their light curves. In all cases, rotation and revolution are synchronous. Synodic periods are 37.728, 16.444, 25.464 and 26.606 h respectively. From a simple model, we have derived their bulk densities as follows: 0.89 ± 0.14, 2.52 ± 0.30, 1.22 ± 0.15 and 0.91 ± 0.10 g cm-3 respectively. Uncertainties in the bulk densities, arising from scattering and shadow effects are not taken into account. These could increase the density estimates by a factor up to 1.6. Our method of determining bulk density is completely independent of their mass and their diameter estimates. The low rotational periods and the low bulk densities clearly imply a collisional process to explain this kind of binary asteroid. Based on our database of a few thousand light curves of minor planets, the population of similar-sized objects in the main belt is estimated to 6± 3 percent in the 10-50 km diameter class.
Conclusions.
Domaines
Astrophysique [astro-ph]| Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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