Observations of two super fast rotator NEAs: 2021 NY$_1$ and 2022 AB

Autor: Licandro, J., Popescu, M., Tatsumi, E., Alarcon, M. R., Serra-Ricart, M., Medeiros, H., Morate, D., de Leon, J.
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1093/mnras/stad708
Popis: In the framework of the Visible NEAs Observations Survey (ViNOS) that uses several telescopes at the Canary Islands observatories since 2018, we observed two super fast rotator NEAs, 2021 NY$_1$ and 2022 AB. We obtained photometry and spectrophotometry of both targets and visible spectroscopy of 2022 AB. Light curves of 2021 NY$_1$ obtained in 4 different nights between Sept. 30 and Oct. 16, 2021 return a rotation period $P=13.3449\pm0.0013$ minutes and a light curve amplitude $A = 1.00$ mag. We found that 2021 NY$_1$ is a very elongated super fast rotator with an axis ratio $a/b \ge 3.6$. We also report colours $(g-r) = 0.664 \pm 0.013$, $(r-i) = 0.186 \pm 0.013$, and $(i-z_s) = -0.117 \pm 0.012$ mag. These are compatible with an S-type asteroid. The light curves of 2022 AB obtained on Jan. 5 and Jan. 8, 2021 show a rotation period $P=3.0304\pm0.0008$ minutes, with amplitudes $A = 0.52$ and $A =0.54$ mag. 2022 AB is also an elongated object with axis ratio $a/b \ge 1.6$. The obtained colours are $(g-r) = 0.400 \pm 0.017$, $(r-i) = 0.133 \pm 0.017$, and $(i-z_s) = 0.093 \pm 0.016$. These colours are similar to those of the X-types, but with an unusually high $(g-r)$ value. Spectra obtained on Jan. 12 and Jan. 14, 2022, are consistent with the reported colours. The spectral upturn over the 0.4 - 0.6 $\mu m $ region of 2022 AB does not fit with any known asteroid taxonomical class or meteorite spectrum, confirming its unusual surface properties.
Comment: 9 pages, 7 figures
Databáze: arXiv