C/2025 A6 (Lemmon) is a non-periodic comet discovered by the Mount Lemmon Survey in images obtained on 3 January 2025. It has an inbound orbital period of about 1,350 years and will pass perihelion on 8 November 2025 when it will be 0.53 AU (79 million km; 49 million mi) from the Sun.¹

This comet could already be imaged at the start of October 2025, but weather did not cooperate. As it climbed above the western horizon and gained magnitude weather deteriorated leaving the western early evening sky overcast for weeks. Then finally, on 22 October a gap in the cloud cover arrived just large enough to do a focus run and 16 minutes of imaging. There was no time to switch to the SkyWatcher Esprit 80ED, so the SkyWatcher Esprit 150ED was used instead.

Adjacent image was taken between 18:18UTC and 18:34UTC using a ZWO ASI1600MM Pro Cool and ZWO LRGB filters.

Stacked in APP, post-processing in Topaz and PSP.

Click here for the full image.

Its distance to Earth this evening was about 0.60AU (91 million kilometres), to the Sun it was 0.64AU (96Mkm).

As the comet's motion (10'38" per hour in the direction of 127.2°) deviates from the background stars a split-processing method was used to produce an image without star-trails. The adjacent image is the result of normal processing and clearly shows the comet's motion and the order in which the filters were used (RGBL).

Click here for the full image.