Topics & Announcements

We would like to share an update of the article (October 15, 2024) reporting the impact of Hurricane Hone (August 24, 2024) on the Subaru Telescope, especially the peeling of the paint on the exterior wall of the dome. Here we report the results of the cross-sectional analysis of the exterior wall, the investigation of the paint material, and the numerical simulation of the paint dispersion range.

The paint was found to have a thickness of 0.02 millimeters, and its composition includes fluoropolymer resin and titanium dioxide as the white pigment. These materials are chemically stable. The total weight of the dispersed paint was estimated to be approximately 14 kilograms, based on the estimated density of the material, the surface area peeled, and its thickness.

We also conducted numerical simulations to estimate the dispersion range. The results indicated that paint flakes that detached and dispersed from the elevator tower were distributed within approximately 100 meters downwind (northwest) from the tower. In addition, the dispersal range of flakes that peeled off from the outer dome wall was estimated to include the area around the dome and extend approximately 250 to 400 meters downwind (northwest). Upon visually inspecting the area near the dome and elevator tower, it was confirmed that small paint flakes, approximately a few millimeters or less in size, were found lodged in the gaps between coarse, granular cinders (volcanic debris).

The likelihood of the paint flakes that have peeled off and scattered being further dispersed by wind or rain is low. We assess that they are likely to remain in their current locations in a stable state, with little concern for any further environmental impact.