There comet C/2025 A6 (Lemmon) has become the brightest of the year, adorning the night skies even in Italy with a brightness that is reaching its peak in these days, so much so that it has become also visible to the eye naked in skies free of light pollution. The celestial body, which reached its closest proximity to the Earth on October 21, is currently shining with magnitude 4.2presenting a green crown and a long tail easily observable with good binoculars or even better a small telescope.
Amateur astronomers and enthusiasts from all over the world are creating truly spectacular images of this celestial body. One in particular that is filming at the moment comes from Italy: its author is Gianluca Masihead of Virtual Telescope Projectwho was lucky enough to capture the comet while due to a perspective effect it appeared to be immersed in a trail of ionized oxygen produced by the passage of a meteor in the Earth’s atmosphere.
According to the reference portal COBS (Comet Observation Database), comet Lemmon is at the maximum of its light curve these days, as can be seen from the graph below. As it moves away from Earth (it is currently about 100 million km away), Lemmon its brightness will progressively decrease. The effect will be gradual and contained until the comet reaches perihelion – the point of its orbit closest to the Sun – on date November 8, 2025 and then becomes faster and becomes invisible to the naked eye again. In fact, let us remember that the “engine” of the brightness of a comet is precisely solar radiation, which causes the volatile materials contained in its nucleus to sublimate and illuminate them.
Currently in Italy the comet is visible in constellation of the Serpent. To locate it, you can look for a diffuse green speck with the naked eye only if you are in particularly dark skies, otherwise it is better to use an auxiliary instrument such as binoculars or a telescope. For the exact position of the comet and the ideal observation time you can help yourself with apps or sites dedicated to astronomical observation.
