Hayabusa2# enstatite-like target 1998 KY₂₆ originating from the Nysa family

¹ Instituto de Astrofísica de Canarias (IAC), C/Vía Láctea s/n, 38205 La Laguna, Tenerife, Spain
² Departamento de Astrofísica, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez, 38206 La Laguna, Tenerife, Spain
³ University of Tokyo, Bunkyo-ku, 113-0033 Tokyo, Japan
⁴ Institute of Space Science – INFLPR Subsidiary, 409 Atomiṣtilor Street, Măgurele, Ilfov 077125, Romania
⁵ University of Craiova, Alexandru Ioan Cuza 13, Craiova 200585, Romania

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 19 January 2026
Accepted: 16 March 2026

Abstract

Context. Following its nominal mission, the Hayabusa2 spacecraft is cruising toward two new targets as part of its extended mission, Hayabusa2# (SHARP: Small Hazardous Asteroid Reconnaissance Probe). The spacecraft will fly by the near-Earth asteroid (98943) Torifune in 2026 and rendezvous with another near-Earth asteroid, 1998 KY₂₆, in 2031. 1998 KY₂₆ was at its brightest in 2024 since its discovery in 1998.

Aims. This study aims to characterize the surface composition of 1998 KY₂₆ and constrain its origin.

Methods. We used the 10.4-meter Gran Telescopio Canarias to obtain a visible reflectance spectrum of 1998 KY₂₆ in May 2024. We analyzed the spectrum for taxonomic classification and compared it with laboratory meteoritic spectra and other E-type asteroids.

Results. The spectrum of 1998 KY₂₆ shows an overall positive spectral slope with no clear absorption feature, which turns flat (neutral) at 0.6-0.7 µm and slightly negative toward 0.9 µm. It is taxonomically classified as an Xe-type (Bus-DeMeo) or X-type (Tholen), while the asteroid’s high geometric albedo (p_V ∼ 0.52) identifies 1998 KY₂₆ as an E-type (Tholen). The spectral shape is consistent with enstatite chondrites (EL/EH).

Conclusions. Considering the spectral shape and the high albedo of 1998 KY₂₆, it quite likely originated from the inner main belt rather than the Hungaria region. These results also suggest a possible relationship to asteroids (44) Nysa and (135) Hertha, which may originate from layers of different reduction states in a parent body.