C/2025 F2 (Swan): A new comet is in the spring sky

Comet C/2025 F2 (SWAN) is best viewed in April with binoculars.

: In late March 2025, Comet C/2025 F2 (SWAN) was discovered by three amateur astronomers using the SWAN camera, leading to its name. Predicted to reach the 8th magnitude by mid-April, it is visible near the constellation Andromeda with the best viewing conditions expected around April 27. The comet will reach its perihelion on May 1, located near the Pleiades in Taurus, visible for just a few more nights from the Northern Hemisphere. After early May, it will be visible only from the Southern Hemisphere as it continues its cosmic journey.

Comet C/2025 F2 (SWAN) was discovered in late March 2025 by three amateur astronomers: Vladimir Bezugly from Ukraine, Michael Mattiazzo from Australia, and Rob Matson from California. These discoverers identified the comet using public images captured by the Solar Wind Anisotropies (SWAN) camera, a device on the Solar and Heliospheric Observatory, which explains the comet's name. Normally, celestial objects are named after their discoverers, but in cases where public tools are used for discovery, the observatory gets the naming credit. This illustrates the importance of public access to advanced tools and data in modern astronomical discoveries.

The comet was initially detected with a brightness of magnitude 11, suitable for medium-sized telescopes in dark observation sites. By early April, it had brightened to magnitude 9, climbing to 8th magnitude. Stargazers equipped with binoculars or telescopes can observe the comet in the pre-dawn sky, positioned 10° above the eastern horizon. However, its visibility is affected by the Full Moon on April 12, which temporarily brightens the sky, potentially making the comet more difficult to spot despite its distance from the Moon's position in the sky.

Throughout mid-April, the comet's trajectory takes it past prominent stars in the Andromeda constellation, aiding its identification. Around April 12-13, it is near Alpheratz, by April 16-17, close to Pi Andromedae, and close to Mirach on April 19-20. Amateur astronomers can use star charts to pinpoint the comet's location as it travels across the sky. Observers should note that the comet is gradually moving lower toward the horizon, aligning further with the constellation Andromeda during these dates. To maximize viewing success, observers should look for the comet just as night falls, especially since its visibility in the Northern Hemisphere will wane.

C/2025 F2 (SWAN) will reach its closest approach to the Sun, known as perihelion, on May 1, lying approximately 30.9 million miles (49.8 million kilometers) from the Sun. On this date, it will be situated just north of the Pleiades star cluster in the constellation Taurus. The comet's brightness predictions suggest it could be a promising target if it achieves 5th-magnitude brightness. However, it will be faint and low in the western sky, requiring observers to begin their search as soon as darkness falls to increase chances of seeing it.

After the first week of May, the comet will vanish from view for Northern Hemisphere observers but will become more prominent in the Southern Hemisphere. There, despite fainting slightly, it rises higher in the sky nightly, providing ongoing observation possibilities for southern stargazers. As a comet spotted via indirect means through the SWAN camera, C/2025 F2 underscores the unique techniques used in celestial discoveries today.

Sources: Astronomy.com, Solar and Heliospheric Observatory

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