C/2025 R3 (PanSTARRS)

C/2025 R3 (PanSTARRS)

C/2025 R3 (PanSTARRS) is a hyperbolic Oort cloud comet that will reach perihelion on 19 April 2026. Around perihelion may reach a naked eye visibility of around apparent magnitude +3. The comet was discovered by PanSTARRS in images obtained on 8 September 2025. By 20 March 2026 it became visible in 10x50 binoculars.

Observational history

Discovery

The comet was spotted in images obtained by the 1.8-m Ritchey-Chretien telescope at Haleakala, Hawaii, as part of the PanSTARRS survey, at an apparent magnitude of about 20. The head of the comet appeared diffuse, about 2.5 arcseconds across, and there was no tail visible. A broad tail 10 arcseconds long was visible in follow-up images by the Canada-France-Hawaii Telescope. On 11 September the comet was 3.60 AU (539 million km) from the Sun.

Follow-up observations

As of early March 2026, it is visible in telescopes just before sunrise about 25 degrees from the Sun. In mid March it had brighened to about magnitude 9. On 20 March 2026 the comet was detected visually in 10x50 binoculars by Alan Hale. On 21 March the tail of the comet was about one degree long.

On 7 April 2026 it will be 33 degrees from the Sun. It will come to perihelion, at 0.499 astronomical units (74,600,000 km; 46,400,000 mi), on 19 April 2026 when it will be 20 degrees from the Sun. Afterwards it will move between the Sun and Earth and its brightness could be boosted by forward scattering. It will reach solar conjunction on 25 April 2026 around 05:23 UT when it will be 3.5 degrees from the Sun. The comet will pass 0.489 AU (73.2 million km) from Earth on 26 April 2026.

Its future (outbound) trajectory shows the comet being ejected from the Solar System.