Science and Exploration

Characterisation Of The New Target Of The NASA Lucy Mission: Asteroid 152830 Dinkinesh (1999 VD57)

By Keith Cowing
Status Report
March 19, 2023
Filed under , , , ,
Characterisation Of The New Target Of The NASA Lucy Mission: Asteroid 152830 Dinkinesh (1999 VD57)
Visible spectrum of asteroid Dinkinesh obtained with the 10.4m Gran Telescopio Canarias (GTC). Error bars correspond to the 1σ of the average of the individual spectra. Reflectance values from the colour photometry obtained with the 4.3m Lowell Discovery Telescope (LDT) using Sloan griz filters are shown as blue squares. Coloured lines are the template spectra of the S-type (red), Sq-type (orange), and Sv-type (yellow) taxons from the DeMeo et al. (2009) taxonomy. The hatched region accounts for the ±1σ dispersion of the spectral classes. — astro-ph.EP

The NASA Lucy mission is aimed at the study of the very interesting population of Jupiter Trojans, considered as time capsules from the origin of our solar system.

During its journey, the mission will pass near a main belt asteroid, Donaldjohanson. Recently, NASA has announced that a new asteroid in the belt will also be visited by Lucy: 152830 Dinkinesh (1999 VD57). The main goal of this work is to characterise this newly selected target, asteroid Dinkinesh, in order to provide critical information to the mission team. To achieve it, we have obtained visible spectra, colour photometry, and time-series photometry of Dinkinesh, using several telescopes located at different observatories.

For the spectra we used the 10.4m Gran Telescopio Canarias (GTC), in the island of La Palma (Spain); for the colour photometry the 4.3m Lowell Discovery Telescope (LDT), near Happy Jack, Arizona (USA) was used; and for the time-series photometry we used the 82cm IAC80 telescope located in the island of Tenerife (Spain). Both visible spectrum and reflectance values computed from colour photometry show that Dinkinesh is an S-type asteroid, i.e., it is composed mainly of silicates and some metal. According to observations done by the NEOWISE survey, S-type asteroids have typical geometric albedo of pV = 0.223 ± 0.073.

From our time-series photometry, we obtained an asteroid mean magnitude r′ = 19.99 ± 0.05, which provides an absolute magnitude Hr′ = 17.53 ± 0.07 assuming G = 0.19 ± 0.25 for S-types. Using our colour-photometry, we transformed Hr′ to HV = 17.48 ± 0.05. This value of absolute magnitude combined with the geometric albedo provides a mean diameter for Dinkinesh of ∼900 m, ranging between a minimum size of 542 m and a maximum size of 1309 m.

J. de León, J. Licandro, N. Pinilla-Alonso, N. Moskovitz, T. Kareta, M. Popescu

Comments: 4 pages, 3 figures, Accepted for publication in A&A
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2303.05918 [astro-ph.EP] (or arXiv:2303.05918v1 [astro-ph.EP] for this version)
Submission history
From: Julia De Leon
[v1] Fri, 10 Mar 2023 13:48:12 UTC (76 KB)

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