Muauna Kea, located on the Big Island of Hawaiʻi, is one of the highest volcanoes in the Pacific Ocean, rising to 4,205m above sea level. Pen ~ fun ~ pavilion www.biquge.info

If you count from the foot of the mountain, which is submerged under the sea, the total height of the peak reaches 10,203 meters, which is more than 1,340 meters higher than Mount Everest.

With dry weather and no light pollution, and more than 300 clear nights a year, it is one of the best places in the world for astronomical observations.

At the summit of Maunaki Volcano, home to 15 observatories from countries around the world and astronomical organizations, Durunik's project team arrived a few months ago to observe the Alpha Centauri system.

It is the early winter season, and the temperature at the summit of the Maonakitian volcano, which is 4,000 meters above sea level, plummets and the air is thin.

The scenery at the top of the mountain is so beautiful that it is impossible to describe in words, perhaps only the most beautiful poetry in the world can describe it.

It seems to be a city in the sky above a sea of clouds, there is no smoke, no hustle and bustle, only a pure ocean, snow-capped mountains and lava.

The sky is nothing but distant and vast......

It was a fine night, and the stars, large and small, had already broken through the night and poked their heads out, and dotted the entire night sky.

At the International Astronomical Center's observatories, Durunik and several other members of the Extraterrestrial Civilizations Project are conducting observations of the Alpha Centauri system.

Suddenly.

"Deputy Team Leader, there is an important discovery!!"

A member of the project team shouted excitedly.

"Combined with the observations of the Superspectral Survey Space Telescope outside the Earth's orbit, the suspected planetary signals that we found before have reappeared today."

"This must not be a coincidence, nor is it a !! error"

The members of several project teams were very excited.

However, when Durunik heard the news, he was not as excited as he imagined, but said with a serious face: "Show me all the observations!" ”

Because, during the observation period of these months, there have been more than one observation oolong incident.

Prior to this, the project team had observed several suspected signals of planetary existence.

However, it was later confirmed that these signals were nothing more than misinformation created by an error in the observing system.

Just like Alpha Centauri Bb, which once caused a huge sensation in the scientific community and was hailed as an epoch-making discovery, they are just "ghosts" that appear on the observation data.

Trunik, as well as the other members of the project team, were particularly cautious at the moment.

Intuition tells them that they get the same suspected signal at different observation locations, different observation equipment, and different observation times, which is obviously unlikely to be just a mistake or coincidence.

"Are you sure you can clearly distinguish between background noise and signal cues?" Durunik asked, looking at the observations.

Obviously, this is a very difficult job.

"There is a certain certainty, but the impact of background noise is still very strong." The project team members replied that although they were very excited about the observations, they were not completely sure.

Any planet is an extremely faint source of light relative to its parent star.

It is extremely difficult to detect such a faint light source at the same time within the dazzling brilliance of the parent star.

Because of this, there are only a few extrasolar planets that we can directly observe.

If we want to find the planets in the Alpha Centauri system, we will have to resort to other indirect methods to detect them.

The researchers who discovered Alpha Centauri relied on the Doppler effect.

That is, if there are planets around the star, the star will expand slightly under gravity, and this change will be reflected in the change in the light emitted by the star, so that it can be captured.

Just as the siren will get higher and higher when a police car is approaching, and the siren will be lower and lower when the police car is far away, if a star is approaching us, the wavelength of the light it emits will shift to the blue end of the spectrum, and conversely, if the star is far away from us, the frequency of the light it emits will become lower, that is, it will move to the red end of the spectrum.

When scientists at the time observed Alpha Centauri B, they found that its spectrum was regularly redshifted and blueshifted, and they explained this change as the star expanding in a three-day cycle due to the gravitational pull of a small planet.

Although there are hundreds of planets in astronomical history that have been presumed to exist due to the slight expansion of stars, these planets are much larger than Alpha Centauri (1.13 times the size of Earth).

As a result, some scholars were skeptical of this discovery and eventually denied the existence of Alpha Centauri due to insufficient observational data.

In this scientific research mission, the methods adopted by the extraterrestrial civilization project team include the transit method, gravity microlensing, arch astrolabe, and the change observation method of orbital phase reflected light.

"This set of data of suspected signals has been tested again by using the transit method." A member of the project team added.

"Hmm." Durunnik responded noncommittally, and then continued to bury his head in the massive amount of observational data.

The so-called transit method is a method of determining the radius of a planet with a photometer.

If a planet passes in front of the disk of the parent star, the visual brightness of the star will decrease slightly, and the amount of dimming of the star depends on the size of the planet relative to the star. For example, the planet HD209458 in the direction of Pegasus dims the brightness of the parent star by 1.7%.

The advantage of the transit method is that the size of the planet can be determined from the light curve. Combined with radial velocity, which can measure the mass of the planet, the density of the planet can be measured, and then more information can be learned about the physical structure of the planet.

At the same time, the transit method also has two major drawbacks.

First, the phenomenon of planetary transits can only be observed if the orbit of the planet is aligned with the observation point of the observing astronomer.

Second, this detection method has a high falsehood rate. The information detected by the transit method usually needs to be rechecked by the radial velocity method.

"Haha, that's kind of interesting!!"

Du Rooney looked at the old man for a long time, and the expression on his face gradually became wonderful.

"Share the details of the observations with all the scientists at other observatories and major space telescopes." Durunik couldn't contain his excitement, and excitedly pointed to the information in his hand and said, "Point all the guns here!" ”

"Do you want to report this new discovery to the team leader?" Other project team members asked.

"Don't worry, wait for the observation results to be further confirmed in the next few days, and then tell the team leader!" (To be continued.) )