GALAXY CRUISE: User characteristics and their evolution in Japan's first big data-driven citizen science project in astronomy

GALAXY CRUISE is the first Japanese online citizen science project in astronomy using big data. It is conducted by the National Astronomical Observatory of Japan (NAOJ) using large datasets collected by the Subaru Telescope near the summit of Maunakea, Hawai‘i. Citizen astronomers classify and identify interacting galaxies on a PC or tablet. The Japanese and English Season 1 sites were launched on 1 November 2019 and 19 February 2020, respectively. Season 1 was completed in April 2022, and we are now in the final phase of Season 2, featuring fainter galaxies. In July 2021, we conducted a user questionnaire in Japanese and English, receiving 245 valid responses. We compared the reasons users indicated for participating in GALAXY CRUISE in the questionnaire with those they selected when registering. In this comparison, we found that the primary motivation for active users is to contribute to astronomy research both when registered and in the questionnaire, and they added more reasons as they continued to participate. The questionnaire results also show that active users have evolved their characteristics into authentic astronomy enthusiasts; they came to spend more time in astronomy and developed an interest for academic astronomy content. In this article, we will present the unique features of this project, the analysis of the user questionnaire, and our latest activities.