Radar observations and a physical model of binary near-Earth asteroid 65803 Didymos, target of the DART mission

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F20%3A00534473" target="_blank" >RIV/67985815:_____/20:00534473 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1016/j.icarus.2020.113777" target="_blank" >https://doi.org/10.1016/j.icarus.2020.113777</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.icarus.2020.113777" target="_blank" >10.1016/j.icarus.2020.113777</a>

Result language

angličtina

Original language name

Radar observations and a physical model of binary near-Earth asteroid 65803 Didymos, target of the DART mission

Original language description

Near-Earth asteroid Didymos is a binary system and the target of the proposed Double Asteroid Redirection Test (DART) mission (Chong et al., 201e), which is a planetary defense experiment. The DART spacecraft will impact the satellite, causing changes in the binary orbit that will be measured by Earth-based observers. We observed Didymos using the planetary radars at Arecibo (2380 MHz, 12.6 cm) and Goldstone (8560 MHz, 3.5 cm) in November 2003. Delay-Doppler radar imaging of the binary system provided range resolutions of up to 15 m/ pixel that placed hundreds of pixels on the primary. We used the radar data to estimate a 3D shape model and spin state for the primary, the secondary size and spin, the mutual orbit parameters, and the radar scattering properties of the binary system. We included lightcurves obtained by Pravec et al. (200e) in the shape model estimation. The primary is top-shaped with an equatorial bulge, a conspicuous facet along the equator, and a volume-equivalent diameter of 780 +/- 30 m. The extents along the three principal axes are 832 m, 838 m, and 786 m, (uncertainties are 6% along the x and y axes, and 10% along the z axis). The radar data do not provide complete rotational coverage of the secondary but show visible extents of about 75 m, implying a diameter of 150 +/- 30 m. The bandwidth of the secondary in the images suggests a spin period of 12.4 +/- 3.0 h that is consistent with rotation that is synchronized with the mutual orbit period of 11.9 h. We fit a mutual orbit to the system using the delay and Doppler separations between the binary components and obtain a semimajor axis of 1190 +/- 30 m, an eccentricity of <0.05, and an orbital period of 11.93 +/- 0.01 h that are consistent with those obtained by Sc heitit h and Prase (2009) and kg and Margot (2012). The mutual orbit implies a system mass of (5.4 + 0.4) x 10(11) kg and a system bulk density of 2170 +/- 350 kg m(-3). The system has S- and X-band radar albedos of 0.20 +/- 0.05 and 0.30 +/- 0.08 respectively, and an optical albedo of 0.15 +/- 0.04.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GA20-04431S" target="_blank" >GA20-04431S: Physical and dynamical properties of space mission target asteroids, and their evolutionary paths</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Icarus

ISSN

1090-2643

e-ISSN

—

Volume of the periodical

348

Issue of the periodical within the volume

September

Country of publishing house

US - UNITED STATES

Number of pages

19

Pages from-to

113777

UT code for WoS article

000541752200004

EID of the result in the Scopus database

2-s2.0-85085185340