Comet C/2025 R3 (PanSTARRS) was discovered in images obtained on September 9th 2025 by the Panoramic Survey Telescope and Rapid Response System (PanSTARRS) in Hawaii. It passed perihelion on April 19th 2026 at a distance of approximately 0.5 AU from the Sun. Shortly thereafter, in early May 2026, the comet became visible to the naked eye with an apparent magnitude of about 3, primarily from the Southern Hemisphere owing to its southern declination.

Prior to its passage through the inner Solar System, the comet’s orbital eccentricity was only slightly below 1, corresponding to a highly elongated periodic orbit with an estimated orbital period of roughly 170,000 years. Gravitational perturbations within the inner Solar System subsequently increased the eccentricity to greater than 1, placing the comet on a hyperbolic trajectory. Unless it experiences further perturbations, it will therefore escape the Solar System permanently.

The image was acquired on May 10th 2026. From the LRGB exposures obtained over a period of approximately one hour, stacked luminance frames with individual exposure times of 240 s were generated at multiple time points. These were combined with a master RGB stack (300 s in each color channel) to produce time-resolved LRGB images separated by intervals of approximately 2.5 minutes. This processing makes it possible to study the pronounced dynamical structure within the comet’s tail. The “still image” (see revision) corresponds to the midpoint of the imaging session, at approximately 17:57 UT, with an effective temporal resolution of 13 minutes, corresponding to the interval during which sixteen 15 s luminance exposures were recorded in an L L L R G B sequence.

Clear skies,
the Capella Observatory team