The Trans-Neptunian Object (84922) 2003 VS2 through Stellar Occultations

DOI: 
10.3847/1538-3881/ab3b05
Publication date : 
27/09/2019
Main author: 
Benedetti-Rossi, Gustavo
IAA authors: 
Santos-Sanz, P.; Ortiz, J. L.; Morales, N.; Duffard, R.
Authors: 
Benedetti-Rossi, Gustavo; Santos-Sanz, P.; Ortiz, J. L.; Assafin, M.; Sicardy, B.; Morales, N.; Vieira-Martins, R.; Duffard, R.; et. al.
Journal: 
THE ASTRONOMICAL JOURNAL
Refereed: 
Yes
Publication type: 
Article
Volume: 
158
Pages: 
17 pp.
Number: 
id. 159
Issue: 
4
Abstract: 
We present results from three world-wide campaigns that resulted in the detections of two single-chord and one multi-chord stellar occultations by the plutino object (84922) 2003 VS2. From the single-chord occultations in 2013 and 2014 we obtained accurate astrometric positions for the object, while from the multi-chord occultation on 2014 November 7, we obtained the parameters of the best-fitting ellipse to the limb of the body at the time of occultation. We also obtained short-term photometry data for the body in order to derive its rotational phase during the occultation. The rotational light curve present a peak-to-peak amplitude of 0.141 ± 0.009 mag. This allows us to reconstruct the 3D shape of the body, with principal semi-axes of a = 313.8 ± 7.1 km, b={265.5}-9.8+8.8 km, and c={247.3}-43.6+26.6 km, which is not consistent with a Jacobi triaxial equilibrium figure. The derived spherical volume equivalent diameter of {548.3}-44.6+29.5 km is about 5% larger than the radiometric diameter of 2003 VS2 derived from Herschel data of 523 ± 35 km, but still compatible with it within error bars. From those results we can also derive the geometric albedo ({0.123}-0.014+0.015) and, under the assumption that the object is a Maclaurin spheroid, the density ρ ={1400}-300+1000 for the plutino. The disappearances and reappearances of the star during the occultations do not show any compelling evidence for a global atmosphere considering a pressure upper limit of about 1 microbar for a pure nitrogen atmosphere, nor secondary features (e.g., rings or satellite) around the main body.
Database: 
ADS
URL: 
https://iopscience.iop.org/article/10.3847/1538-3881/ab3b05
ADS Bibcode: 
2019AJ....158..159B
Keywords: 
Trans-Neptunian objects; Kuiper belt