A comet can be seen with the naked eye on Sunday in Portugal, in a short window of opportunity that opens at 7:35 pm (Lisbon time).
This is comet C/2023 A3 Tsuchinshan-ATLAS, detected in January 2023 by telescopes at the Tsuchinshan Observatory, in China, and confirmed by the ATLAS telescope in South Africa.
Speaking to Lusa, astrophysicist Nuno Peixinho said that, if sky observation conditions remain cloudless, the comet could be seen with the naked eye in Portugal on Sunday “40 minutes after sunset, looking west , that is, at 19:35”.
According to the researcher from the Institute of Astrophysics and Space Sciences, “the window of opportunity” to observe the comet, preferably from a place with little light pollution, “is small”, since after 8 pm “it is already very low on the horizon and it will be very difficult to see it.”
Nuno Peixinho draws attention to “not confuse” the comet with “the strong brightness of the planet Venus”, which, on the horizon, will be to its left.
On Sunday, the Geophysical and Astronomical Observatory of the University of Coimbra will promote an observation session between 7:20 pm and 8 pm.
On that day, according to Nuno Peixinho, the comet will be almost 71 million kilometers from Earth and just over 82 million kilometers from the Sun, when “the average distance from Earth to the Sun, called an astronomical unit, is around 150 million kilometers”.
According to the astrophysicist, the comet could still be observed next week, but possibly only with the help of a telescope, as it loses luminosity daily as it moves further and further away from the Earth and the Sun.
After its passage close to Earth, comet C/2023 A3 Tsuchinshan-ATLAS will continue its journey through the confines of the Solar System, possibly influenced by the gravity of other planets or stars.
Orbital models suggest that the comet will not come close to Earth again for hundreds of thousands of years, if it ever returns.
Comet Tsuchinshan-ATLAS comes from the Oort Cloud, a vast and distant reservoir of icy celestial bodies that surrounds the Solar System.
Before being visible in October in the Northern Hemisphere, the comet could be observed at the end of September in the Southern Hemisphere, towards the east of the horizon, at dawn.
By definition, comets are celestial bodies formed by ice, dust and small rocky particles. As they approach the Sun, their brightness increases, as the icy materials that compose them sublimate, generating a diffuse atmosphere around their core, called a coma, and a tail, pointed in the opposite direction to the Sun.
