Overview

• Comet Lemmon (C/2025 A6) remains visible before dawn near the Big Dipper and, starting Monday, Oct. 13, also appears low in the northwest about 90 minutes after sunset.
• Comet SWAN (C/2025 R2) is best sought roughly 90 minutes after sunset in the southwest, positioned near bright stars Sabik and Antares.
• Recent estimates place Lemmon at magnitude +5.7 and SWAN near +6, making binoculars or small telescopes the practical choice for viewing right now.
• Closest approaches are forecast for Oct. 20–21 — SWAN around Oct. 20 at about 24 million miles from Earth and Lemmon around Oct. 21 at about 63 million miles — with peak brightness expected around those dates.
• Lemmon was discovered in January by the Mount Lemmon Survey, SWAN was identified in September in SOHO/SWAN data, and both show a green hue linked to carbon-bearing gases; finder charts from In-The-Sky.com and similar tools can aid locating them.