Delights at night

"The last time a comet visible to the naked eye appeared in the northern hemisphere was the Hale-Bopp comet 23 years ago. I was preparing for the college entrance examination, and I didn't have the chance to see it in person. This time, the comet Neowise, number C/2020 F3, is very unexpected. No one thought that it could increase to the brightness of a magnitude 1 star. Now it is the new favorite of our star chasers," says astronomy enthusiast Li Peng.

In order to avoid the interference of city lights and better observe the comet Neowise, Li and his friends drove 500 kilometers from Beijing to the Ulan Butong grassland of Inner Mongolia to take pictures. A celebrity in Beijing's astronomical circle, Li has devoted himself to astronomical science for a long time and always pays attention to important astronomical phenomena.

On March 27, comet Neowise was discovered by NASA's wide-area infrared survey satellite, and was named after its exploration mission "Neowise".

At that time, its brightness was only about magnitude 18, about 300 million kilometers away from the sun, and about 250 million kilometers away from the Earth. The comet number is C/2020 F3, in which C means it is a long-period or aperiodic comet, and 2020 F3 means that it is the third comet discovered in the second half of March 2020.

This comet is visible to the naked eye throughout July and will quickly disappear, grabbing the world's attention, especially that of astronomers and star chasers around the world. In Li's view, although comet Neowise could not be as brilliant and eye-catching as comet Hale-Bopp back then, it is extremely rare to be visible.

The now-famous comet Neowise was actually a little "transparent" when it was first discovered. As it gets closer and closer to the sun, it gets brighter, and it is close to magnitude 6 in brightness in early June. But when it traveled to the back of the sun, the comet disappeared from people's vision. It wasn't until half a month later that it once again appeared, at which time its brightness had reached magnitude 2.5.