Interstellar object 3I/ATLAS = C/2025 N1 (ATLAS): coma detection – 31 July 2025
On 31 July 2025, we imaged 3I/ATLAS = C/2025 N1 (ATLAS), as part of our coverage of this exceptional object. We succeeded detecting its faint coma.
The interstellar object 3I/ATLAS = C/2025 N1 (ATLAS), imaged on 31 July 2025.
The image above comes from the combination of 13, 120-second exposures, remotely taken with the Celestron C14+Paramount ME+SBIG ST10-XME robotic unit available as part of the Virtual Telescope Project in Manciano, Italy. The frames used to assemble the final image were median combined, in order to remove the interference from the stars on the background as much as possible. Then, it was inverted, to show the faint coma of the object, which is very clear.
3I/ATLAS is the third interstellar object ever discovered, after 1I/ʻOumuamua in 2017 and 2I/Borisov in 2019. From the beginning, its interstellar nature was evident due to its high velocity at infinity (hyperbolic excess velocity) of nearly 60 km/s, corresponding to a strongly hyperbolic orbit with an eccentricity of 6.1, by far the highest among the three interstellar objects known to date. Its estimated diameter is around 10 km.
3I/ATLAS will reach perihelion (closest point to the Sun) on October 29, passing at just over 200 million km from our star at a speed of about 68 km/s. On October 3, it will be only 30 million km from Mars, and on December 19, it will make its closest approach to Earth, passing at around 270 million km from our planet.
From Earth, 3I/ATLAS is currently visible between the constellations of Ophiucus and Scorpius, in the first part of the night. It can be photographed using telescopes with 150–200 mm of aperture.
Support The Virtual Telescope Project!
Support us! Please, donate and receive an EXCLUSIVE image of the stunning COMET C/2023 A3 Tsuchinshan-ATLAS and much more, specifically made for supporters like you!
