Comet 220P/McNaught reached its perihelion, or closest point to the Sun, on June 14, 2026, following a rare and massive brightness outburst that increased its magnitude by nearly 10 points. According to Astronomy magazine, the comet jumped from 18th magnitude to nearly magnitude 8 in a single day, marking one of the most significant brightening events ever recorded for the object.
Why do comets like 220P/McNaught experience sudden outbursts?
Comet outbursts occur when a pocket of volatile material beneath the comet’s surface is exposed to solar radiation, causing a rapid release of gas and dust. This process, often called an “outburst,” significantly increases the surface area reflecting sunlight. Dr. Alison Klesman, senior editor at Astronomy, notes that while the comet has begun to fade from its peak, it remains brighter than its pre-outburst levels, currently hovering around 12th magnitude.
To spot 220P/McNaught, use the planet Saturn as your guide. The comet is currently located approximately 4.7° west of Saturn in the constellation Pisces. Observers should look roughly two hours before dawn when the region reaches an altitude of 20° in the eastern sky.
How does 220P/McNaught compare to other periodic comets?
Comet 220P/McNaught follows a 5.5-year orbital path, which classifies it as a short-period comet. When compared to 10P/Tempel, another comet currently approaching its own perihelion later this summer, 220P/McNaught is notable for its unpredictable volatility. While 10P/Tempel follows a more expected brightness curve, 220P/McNaught’s recent 10-magnitude jump highlights the erratic nature of cometary activity, which can frustrate but also reward amateur astronomers.
What should observers expect as the comet moves away from the Sun?
As 220P/McNaught moves past its June 14 perihelion, it is expected to gradually fade. However, astronomers caution that cometary behavior remains notoriously difficult to predict. According to observations reported by Astronomy, there is always the possibility of a secondary outburst. Observers are encouraged to keep monitoring the region near Saturn, as the comet’s trajectory remains favorable for viewing in the early morning hours throughout the coming weeks.
The green glow observed in the coma of 220P/McNaught is caused by diatomic carbon (C2) molecules, which fluoresce when exposed to ultraviolet solar radiation. This is a common feature in many active comets.
Frequently Asked Questions
Is Comet 220P/McNaught visible to the naked eye?
No. Even at its peak brightness of magnitude 8, the comet is too faint to be seen without the aid of binoculars or a telescope.
When is the best time to view the comet?
The best time to observe the comet is in the early morning hours, approximately two hours before sunrise, when it is positioned about 20° above the eastern horizon.
Will the comet brighten again?
While the comet is currently fading, unexpected outbursts are possible. Periodic monitoring is required to track any further changes in its magnitude.
Have you managed to capture an image or a glimpse of Comet 220P/McNaught? Share your experiences in the comments below or subscribe to our weekly newsletter for more updates on upcoming celestial events and observing tips.
