Final Chance To See Comet Pan-STARRS At Its Brightest This Sunday — When To Look

Jamie Carter, Senior Contributor

Sat, April 18, 2026 at 7:00 AM UTC

4 min read

Topline

A brightening comet reaches a key moment on Sunday morning when it reaches its brightest. Comet C/2025 R3 (Pan-STARRS) will be at perihelion, its closest point to the sun, a stage when comets often become more active and begin to brighten more rapidly. At the same time, Mercury and Mars are gathering low in the eastern sky for early risers who keep looking after the comet is swallowed up by the gathering dawn. However, this ins one of your final chances to see the comet — so act fast. Remember to check my feed for the latest on comet Pan-STARRS.

Comet 2024 G3 ATLAS Over the Warrumbungles — Comet Pan-STARRS, also known as comet C/2025 R3 (Pan-STARRS), is now visible before sunrise. (Image shows Comet C/2024 G3 (ATLAS)).
getty

Key Facts

Comet C/2025 R3 (Pan-STARRS) is visible from about 90 minutes before sunrise until early next week — a very brief window. An unobstructed view of the eastern horizon is crucial.

On Sunday, April 19, the comet lies due east close to bright star Algenib at the lowest corner of the Great Square of Pegasus. As the comet fades from view in the brightening dawn sky, observers may see Mercury and possibly Mars beneath, very close to the horizon just before sunrise.

According to the Comet OBServation database , the comet is currently shining at around magnitude +4.7 — right on the cusp of being a naked-eye object in very dark skies. However, it will likely require binoculars for most observers.

The comet will reach perihelion on Sunday, April 19, with its closest approach to Earth on Monday, April 27 (though by then it will be impossible to see from the Northern Hemisphere).

Observers in the Southern Hemisphere will be able to spot the comet from late April, after the comet passes perihelion, just after sunset on the western horizon.

It was discovered by the Pan-STARRS survey in Hawaii in September 2025 and is thought to orbit the sun roughly every 170,000 years.

April 19 - with Algenib — The position of comet C/2025 R3 (Pan-STARRS) 90 minutes before sunrise on April 19, 2026.
Stellarium

Comet Tracker For Sunday, April 19

On April 19, Comet C/2025 R3 (Pan-STARRS) reaches perihelion at about 0.50 AU (75 million kilometers) from the sun while closing to roughly 0.59 AU (88 million kilometers) from Earth — a key moment that may accelerate its brightening. Here’s how to find it:

How To Find Comet Pan-Starrs

The comet will appear as a faint, diffuse glow, but steadily brightening as it approaches the sun.

Go outside about 90 minutes before sunrise where you are and look low in the eastern sky.
The key is to first locate the Great Square of Pegasus rising due east — a large, diamond-shaped pattern of four stars.
Now look for the lowest of the square’s four corner stars, closest to the horizon. That’s Algenib. The comet will be just to the left of this star.
Look for a small misty patch of light — and hopefully a tail — using a pair of 10x50 binoculars to make it easier.
If you have binoculars, scan close to the eastern horizon for Mercury, and possibly Mars.

Structure_of_a_comet — Structure of a comet.
ESA

Why Perihelion Matters

Perihelion is when a comet is closest to the sun — and when the action often begins. As a comet approaches the sun, increasing heat causes frozen gases inside the comet to vaporize more rapidly. That releases dust and gas into space, building up the coma and tail and often leading to a noticeable increase in brightness. Not all comets respond dramatically, but this is the point when changes can begin to accelerate. Sadly for the Northern Hemisphere, it’s also where the action for Comet Pan-STARRS ends because it now drops out of view, lost in the sun’s glare.

How To Photograph A Comet

If you can’t see the comet easily, photograph it. Even a basic smartphone on a tripod using night mode can reveal a faint comet as a soft green glow, often with hints of a tail. With a manual camera, try 5-30 second exposures at ISO 800-3200 and a wide aperture (around f/2.8). Focus on a bright star first, then compose your shot. In many cases, your camera will “see” the comet before your eyes do — though binoculars will hugely help.

Check my feed for a daily “comet tracker” with sky charts and tips for finding Comet Pan-STARRS.