Comet C/2025 A6 (Lemmon) was discovered only recently — in January of this year — and has already captured the attention of astronomers worldwide. It returns to the Sun roughly once every 1,350 years, which means this is our only chance to see it in our lifetime.
Right now, C/2025 A6 is gradually brightening and has every chance of becoming one of the highlights of the night sky by late October, when it approaches the Sun.
Its emerald glow isn’t accidental. The green color comes from diatomic carbon (C₂) in the coma: under the influence of solar ultraviolet radiation, these molecules fluoresce and emit strongly in that part of the spectrum.
| Camera | ZWO ASI2600MC |
| Optics | Askar 103 APO |
| Mount | UMi 17S |
| Gain | 0 |
| Sensor Temperature | 0 °C |
| F-ratio | f/7 |
| Exposure | 50 × 60 s |
| Total Integration | 0.83 h |
| Processing | Siril, GraXpert, GIMP |
