Comet C/2025 R3 (PanSTARRS)
Description:
Comet C/2025 R3 PanSTARRS is coming from the far reaches of the solar system. It’s on a 170,000-year orbit and was hurtling towards the Sun, which it circled on April 19, 2026. It survived this close encounter, but its orbit will be altered, and it will likely be ejected from the solar system. This was probably the only opportunity I could have to photograph it on the morning of April 17, 2026, but it’s close to the Sun and low on the horizon. It’s a real challenge.
Technical details:
The first image was taken on April 17, 2026, with an 81mm William Optics telescope and a ZWO ASI 2600MC camera. It is a stack of 10 60-second exposures taken when the comet was only 9 degrees above the eastern horizon and the approaching sunrise was beginning to obscure the tail.
The bluish ion tail, made of CO+ pushed by the solar wind, is clearly visible, as is the more yellowish dust tail, and the nucleus, which is green due to the presence of diatomic carbon (C2). The ion tail exhibits undulations caused by variations in the solar wind.
The second image was taken on April 12, 2026, with a Canon EOS 6D Mark II camera and a Samyang 135mm f/2.0 lens. It is a stack of 51 3.2-second exposures at ISO 1600.
