Comet C/2025 A6 Lemmon is unlikely to show its tail to the average person with binoculars. Early forecasts of rapid comet brightness growth, as well as information about the body's current magnitude, require clarification, noted the Laboratory of Solar Astronomy of IKI and ISZF.
The body's magnitude, which is about 6 units, is above the sensitivity threshold of the eye, but only for compact bodies (stars, planets), all of whose radiation is concentrated in one point, the laboratory explained. Only experienced observers with star-gazing skills will be able to make out the central body of the comet, like a very faint star, in strong professional binoculars.
Comet C/2025 A6 Lemmon currently occupies several square degrees in the sky, and the "smearing" of radiation over such an area leads to a sharp decrease in the surface brightness of the tail.
At the moment, the body as a comet, that is, a nucleus with a tail, can be observed to a limited extent in good lenses with high aperture ratio with an exposure time of several tens, and preferably at least 100 seconds. Obtaining more or less high-quality photographs is possible in telescopes with an aperture diameter of 100 mm and with approximately the same total exposure time.
In general, it is now almost clear that the expectations for the comet's visibility, which were still there 2 weeks ago, turned out to be greatly exaggerated. At the moment, based on the growth of radiation flux and surface brightness of the body, the possibility of seeing it with the naked eye, even at its peak brightness, seems very unlikely.
The body will reach its maximum brightness around October 30, when it will increase its luminosity by about 15 - 20 times relative to the current value. This, unfortunately, will be absolutely insufficient for visual observation of the object, especially when it comes to simple hand-held observations.
Earlier www1.ru wrote that comet C/2025 A6 will approach Earth in October.