TY - JOUR
T1 - Radar and Optical Observations and Physical Modeling of Binary Near-Earth Asteroid 2018 EB
AU - Brozović, Marina
AU - Benner, Lance A.M.
AU - Naidu, Shantanu P.
AU - Moskovitz, Nicholas
AU - Giorgini, Jon D.
AU - Virkki, Anne K.
AU - Marshall, Sean E.
AU - Dover, Lord R.
AU - Rożek, Agata
AU - Lowry, Stephen C.
AU - Warner, Brian D.
AU - Taylor, Patrick A.
AU - Rivera-Valentin, Edgard G.
AU - Lister, Timothy A.
AU - Chatelain, Joseph P.
AU - Busch, Michael W.
AU - Magri, Christopher
AU - Jao, Joseph S.
AU - Snedeker, Lawrence G.
AU - Lawrence, Kenneth J.
N1 - Publisher Copyright:
© 2024. The Author(s). Published by the American Astronomical Society.
PY - 2024/5/28
Y1 - 2024/5/28
N2 - We report radar, photometric, and visible-wavelength spectrophotometry observations of NEA 2018 EB obtained in 2018. The radar campaign started at Goldstone (8560 MHz, 3.5 cm) on April 7, and it was followed by more extensive observations from October 5 to 9 by both Arecibo (2380 MHz, 12.6 cm) and Goldstone. 2018 EB was observed optically on April 5, 8, and 9 and again on October 18. Spectrophotometry was obtained on October 19 with the SOAR telescope, and the data suggest that 2018 EB is an Xk-class object. The echo power spectra and delay-Doppler radar images revealed that 2018 EB is a binary system. Radar images constrained the satellite's diameter to 0.15−0.05+0.02 km, but the data were not sufficient for shape modeling. Shape modeling of lightcurves and radar data yielded an oblate primary with an effective diameter D = 0.30 ± 0.04 km and a sidereal rotation period of 4.3−0.5+0.6 hr. Measurements of delay-Doppler separations between the centers of mass of the primary and the satellite, along with the timing of a radar eclipse observed on October 9, resulted in an orbit fit for the satellite with a semimajor axis of 0.50−0.01+0.04 km, an eccentricity of 0.15 ± 0.04, a period of 16.85−0.26+0.33 hr, and an orbit pole constrained to the ecliptic longitudes and latitudes of λ = 93− 43 °+27° and β = 48−18°+7° . The system mass was estimated to be 2.03−0.08 + 0.52×1010 kg, which yielded a bulk density of 1.4−0.5+0.6 g cm−3. Our analysis suggests that 2018 EB has a low optical albedo of pV = 0.028 ± 0.016 and a relatively high radar albedo of ηOC = 0.29 ± 0.11 at Arecibo and η = 0.22 ± 0.10 at Goldstone.
AB - We report radar, photometric, and visible-wavelength spectrophotometry observations of NEA 2018 EB obtained in 2018. The radar campaign started at Goldstone (8560 MHz, 3.5 cm) on April 7, and it was followed by more extensive observations from October 5 to 9 by both Arecibo (2380 MHz, 12.6 cm) and Goldstone. 2018 EB was observed optically on April 5, 8, and 9 and again on October 18. Spectrophotometry was obtained on October 19 with the SOAR telescope, and the data suggest that 2018 EB is an Xk-class object. The echo power spectra and delay-Doppler radar images revealed that 2018 EB is a binary system. Radar images constrained the satellite's diameter to 0.15−0.05+0.02 km, but the data were not sufficient for shape modeling. Shape modeling of lightcurves and radar data yielded an oblate primary with an effective diameter D = 0.30 ± 0.04 km and a sidereal rotation period of 4.3−0.5+0.6 hr. Measurements of delay-Doppler separations between the centers of mass of the primary and the satellite, along with the timing of a radar eclipse observed on October 9, resulted in an orbit fit for the satellite with a semimajor axis of 0.50−0.01+0.04 km, an eccentricity of 0.15 ± 0.04, a period of 16.85−0.26+0.33 hr, and an orbit pole constrained to the ecliptic longitudes and latitudes of λ = 93− 43 °+27° and β = 48−18°+7° . The system mass was estimated to be 2.03−0.08 + 0.52×1010 kg, which yielded a bulk density of 1.4−0.5+0.6 g cm−3. Our analysis suggests that 2018 EB has a low optical albedo of pV = 0.028 ± 0.016 and a relatively high radar albedo of ηOC = 0.29 ± 0.11 at Arecibo and η = 0.22 ± 0.10 at Goldstone.
UR - http://www.scopus.com/inward/record.url?scp=85194960452&partnerID=8YFLogxK
U2 - 10.3847/PSJ/ad4342
DO - 10.3847/PSJ/ad4342
M3 - Article
AN - SCOPUS:85194960452
SN - 2632-3338
VL - 5
SP - 1
EP - 23
JO - Planetary Science Journal
JF - Planetary Science Journal
IS - 5
M1 - 123
ER -