J/A+A/697/A157 Occultation light-curves 2007 OC10 (Gomez-Limon+, 2025)
Size and shape of the trans-Neptunian object (470316) 2007 OC10:
Comparison with thermal data.
Gomez-Limon J.M., Leiva R., Ortiz J.L., Morales N., Kretlow M.,
Vara-Lubiano M., Santos-Sanz P., Alvarez-Candal A., Rizos J.L., Duffard R.,
Fernandez-Valenzuela E., Kilic Y., Cikota S., Sicardy B., Bragas-Ribas F.,
Alarcon M.R., Alis S., Benkhaldoun Z., Burdanov A., de Wit J.,
Calavia Belloc S., Calvo Fernandez J., Canales Moreno O., Catanzaro G.,
Fisek S., Frasca A., Iglesias-Marzoa R., Infante-Sainz R.,
Jimenez-Guisado A., Kaspi S., Kuutma T., Lafuente Aznar D., Licandro J.,
Maestre J.L., Martorell P., Nastasi A., Occhipinti G., Perello C.,
Rinner C., Samper-Domenech B., San Segundo A., Santana-Ros T.,
Serra-Ricart M.
<Astron. Astrophys. 697, A157 (2025)>
=2025A&A...697A.157G 2025A&A...697A.157G (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets ; Occultations ; Photometry ;
Optical ; Infrared
Keywords: astrometry - occultations - Kuiper belt: general -
Kuiper belt objects: individual: 2007 OC10
Abstract:
The shapes of only 12 trans-Neptunian objects have been directly
measured, offering crucial insights into their internal structure.
These properties are strongly connected to the processes that shaped
the early Solar System, and provide important clues about its
evolution.
The aim of the present work is to characterise the size, shape,
geometric albedo, and beaming parameter of the TNO (470316) 2007 OC10.
We compared these values to the effective diameter and geometric
albedo obtained from thermal data by the TNOs are Cool survey. We also
combined occultation and thermal data to constrain the size of a
putative unresolved satellite.
We predicted an occultation of the star Gaia DR3 2727866328215869952
by 2007 OC10 on 2022 August 22. Four stations detected the
occultation. We implemented an elliptical shape model for the
projection of 2007 OC10. Following a Bayesian approach, we obtained
the posterior probability density in the model parameter space using a
Markov chain Monte Carlo method.
The elliptical limb of 2007 OC 10 has semi-axes of
215-7+10x141-23+24km, and thus the projected axis ratio is
b/a=0.58-0.16+0.16. The area-equivalent diameter is 330-55+56 km.
From our own absolute magnitude value of HV=5.40±0.02, the geometric
albedo is pV=11.2-5.0+2.1%. Combining the occultation results with
thermal data, we constrain the beaming parameter to
eta=1.42-0.58+0.75. Occultation data reveal that the star is
double. The secondary star has a position angle with respect to the
primary of 56-17+3 degrees, has an angular separation of
57-11+4mas, and is 1.18-0.07+0.07 magnitudes fainter than the
primary.
Description:
From the analysis of the occultation the present light curves, an area
equivalent diameter of 330+56-55km and axis ratio of
0.58+0.16-0.16 were found. Combined with our own derived value of
Hv=5.40±0.02mag, the resulting geometric albedo is
pv=11.2+2.1-5.0%. Combined with thermal data from the "TNOs are
Cool" project, the obtained beaming parameter is 1.42+0.75-0.58.
An upper limit on the diameter of a putative unresolved satellite can
be set when combining occultation and thermal data. The double star
could also be characterised: The magnitude difference is
1.18+0.07-0.07, the position angle on the sky-plane is 56+3-17
degrees and the angular separation is 57+4-11mas.
Light-curves corresponding to the occultation of GDR3
2727866328215869952 by (470316) 2007 OC10 on 2022-08-22.
The fluxes have been normalized.
object.dat :
--------------------------------------------------------------------
Planet Name H i e a
mag deg AU
--------------------------------------------------------------------
470316 2007 OC10 5.28 21.658506 0.29393967 50.26909557
--------------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
albox.dat 23 1509 Light-curve from albox
artemis.dat 23 532 Light-curve from artemis
botorrit.dat 23 1199 Light-curve from botorrita
canakkle.dat 23 446 Light-curve from canakkle
el_guijo.dat 23 299 Light-curve from el_guijo
gal_hass.dat 23 155 Light-curve from gal_hassin
guirguil.dat 23 55 Light-curve from guirguillano
javalamb.dat 23 491 Light-curve from javalambre
liverpoo.dat 23 700 Light-curve from liverpool
oukaimed.dat 23 3000 Light-curve from oukaimeden
sln.dat 23 1500 Light-curve from sln
tar2.dat 23 271 Light-curve from tar2
wise.dat 23 1254 Light-curve from wise
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Byte-by-byte Description of file: *.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 s Time Time (JD-2450000), scale: seconds from midnight
11- 16 F6.4 --- Flux Normalized flux of target stars
18- 23 F6.4 --- e_Flux Uncertainty in normalized flux
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Acknowledgements:
Jose Maria Gomez-Limon,, jgomez(at)iaa.es
(End) Patricia Vannier [CDS] 12-Mar-2025