October Comet Near Corona Borealis
- Chuck Bueter
- Oct 4
- 2 min read
Updated: Oct 8
One of several comets passing through the inner solar system in October 2025 will be in the starfield containing the constellation Corona Borealis (CrB). So if you are regularly imaging CrB in hopes of catching an anticipated nova there, as I am, you may capture a bonus comet in the field of view.
Opening October, Comet C/2025 A6 Lemmon is under the Big Dipper in the morning sky, but transitions mid-month to an evening target. After October 20, its closest point of approach to earth, Comet Lemmon is moving daily from right to left through Bootes, whose bright star Izar is one of the key stars for finding the site of the recurring nova in CrB.
As an added bonus, the night of October 20-21 is the peak of the Orionid meteor shower, remnants from Halley's Comet. That night is a trifecta of highlights.

Comet Lemmon will be low in the twilight and setting further, so a clear western horizon is needed. You're playing a timing game of it being dark enough before the comet is too low in the horizon haze. Some astronomers suggest Comet Lemmon may become naked-eye visible from dark skies. However, a long duration exposure with a cell phone in night mode will likely pick up the comet.
In an image from October 5, 2025, taken with a cell phone before sunrise, the comet appears without a tail near the Tania pair of stars.

One year ago, Comet Tsuchinshan-ATLAS similarly passed through the starfield containing Corona Borealis.