Chapter 2859 Hagrid’s Holiday (9)

The reason why Cepheid variable stars are called this name is because John Goodley discovered δ Cephei in 1784. Its apparent star level is 3.7 at its brightest, 4.4 at its dimmest, and has a photoperiod of 5.37 days.

Stars that change their brightness regularly can be regarded as a "heartbeat". Cepheid is a binary star. Its main star is a yellow supergiant or bright giant, and the companion star is blue-white. Since there is not much difference between the two, and their

It is not massive enough to explode as a supernova, so it should eventually shrink into a white dwarf.

There is a bright reflection nebula in the constellation Cepheus, called the Iris Nebula. If the weather is good, you can observe it with a large-diameter telescope. It is the dust produced after a supernova explosion. The reason why it can be seen is

Because there is a star nearby and the dust reflects the light, you can see the iris-like blue color. Sometimes it is also nicknamed the "Iris Nebula".

Not every nebula is a galaxy. Even if there is red light in the center of the Iris Nebula, it is not a star. It is just the matter in the dust center that has changed under ultraviolet light.

This is the most brilliant "firework" in the universe, although it means the death of a massive star.

Like many yellow giant stars, Cepheid begins to burn helium after burning hydrogen, but at this time it is not able to produce materials heavier than helium like red giants. A helium ionization layer will be formed inside the star, allowing the ionized helium to continue

Ionization. At first, the yellow giant star will expand. Due to the contraction of gravity, the secondary ionized helium will turn into primary ionized helium and release heat outward. As the radiation pressure accumulates, it will eventually exceed the gravity and continue to expand as before.

Then it shrinks due to gravity, and the cycle continues until the helium is burned out and shrinks into a white dwarf.

In ancient Greek mythology, Poseidon's wife was very angry because her mother Cassiopeia kept showing off her beauty. She asked Poseidon to "avenge" her. Poseidon asked whales to ravage the kingdom of the fairy king.

The fairy king asked the oracle, and the oracle revealed that the way to rescue him was to sacrifice Andromeda, the daughter of the fairy king and Cassiopeia.

She was chained by her parents on the road that Cetus must pass. She was seen by the hero Perseus, so Perseus immediately took out the head of the Gorgon Medusa, petrified Cetus, and rescued Perseus.

Got her.

"Medusa's Eye" is located in the constellation Perseus. It is also a variable star in a binary star system, but it is different from Cepheid. It has a companion star that is much dimmer than the main star. When the companion star orbits between the observer and the main star

, a stellar eclipse will form, covering the main star and dimming the "Eye of Medusa" for about 10 hours. After the eclipse is over, the brightness will recover.

Therefore, the "Eye of Medusa" in Perseus cannot become a "candlelight" or a celestial ruler, because it is not a member of the Cepheid variable star family.

The Large and Small Magellanic Clouds cannot be seen in the northern hemisphere, but they are the most spectacular landscapes in the southern hemisphere and are also the objects that astronomers have been pursuing. Charles Pickering, who had just taken over the Harvard University Observatory, commissioned his brother William Pickering to go to Peru to establish the

He built an observatory and took a large number of photos of the Magellanic Clouds, so that Charles Pickering could obtain starry sky photos of the northern and southern hemispheres.

However, with the photos and technology at that time, it was impossible to take pictures of the gorgeous starry sky, only black and white, which looked like white spots on a blackboard that could not be wiped clean.

Pickering hired someone to classify these stars, but men were simply not capable of such boring, repetitive work that required patience and care. Charles soon discovered that the male staff he hired was not as good as his maid, so he

I simply hired a group of women to process the increasing number of photos that accumulated over time.

At the beginning of the 20th century, women's status was extremely low, and there were few jobs for them, especially in the intellectual world. Pickering overcame the difficulties and formed such an all-female team. They were nicknamed "Pickering's harem"

”.

After getting the opportunity, they went all out to process the long-accumulated starry sky photos from the northern and southern hemispheres. In addition to stars, there were also novae and supernovae that suddenly appeared and then disappeared. This was the main material Pickering needed.

The deaf and mute Henrietta, although highly educated, was unable to communicate with other members of the team. Moreover, she was frail and would suddenly be unable to work. Pickering arranged for her to deal with dispensable variable stars.

But it was precisely because she couldn't hear the noisy sounds in the office that she could concentrate on discovering this small detail.

Women include all women over the age of 14, not just young and beautiful "goddess". There may be 15-year-old "women" who think, "How can I be like that fat, old housewife?"

Now, please sit down with this beautiful "goddess". Let's talk about gravitational lenses and Einstein rings. After that, we'll talk about the celestial dance.

Gravitational lensing is because massive objects can bend space-time, and the curved space-time can be equivalent to a lens, which has the effect of a magnifying glass and allows humans to see farther into the starry sky.

Wizards can bend time and space, and apparation is similar to a "wormhole", although not as far away as being able to travel to Proxima Centauri.

Priya Moore's work in the Department of Mysteries is about space, although it appears to be the study of planets, and it is also the solar system.

When Ben Cooper went to pick up the time turner that day, her "former colleague" asked about her situation. She seemed to be in quite a lot of trouble. It was not easy to become a silent person at such a young age. Otherwise, Director Michael

Gen wouldn't be so angry and sent her to the centaur's office all at once.

It’s more sad to not have a chance to work hard than to not succeed. At least those Flobber caterpillars have someone to feed them. What will they eat if they don’t work?

But if Henrietta was allowed to spin yarn like the female textile factory workers, would there still be this great discovery in astronomy, or even change human cognitive concepts?

In the past, during the summer vacation, Albus would care about what Hagrid was doing and what new magical animals he had bred, but recently he was "playing" with Severus.

Pomona ignored the flying dragonflies, but Severus chased them, and then he discovered a new secret room.

It was just behind the stone dragon sculpture, covered by a tapestry. She didn't know how he found it and got in. In short, he and Dumbledore were "spending time" there.

Now Pomona tried to look for dragonflies, but couldn't find any. It seemed like they were all hiding.

In this case, she went to the Forbidden Forest. There was nothing to stay in the castle anyway, and there was a dangerous "beast" lurking.

In Principal Moore's time, there had never been any fatal attacks on Muggles. It didn't matter that she released the clever key for the students to chase, but it would be very risky to do so now.

Maybe she should catch all the dragonflies in the castle before school starts.

Fortunately, Hagrid doesn't care about the problem of continuing to make the Flobber caterpillar "useful". He is training the three-headed hell dog Fluffy given to him by Carter not to take food from other heads.

His progress didn't seem to be very good. Anyway, Pomona saw that the middle head was often fighting with the left and right heads, and the left and right heads couldn't fight because they were separated by the middle head.

Everyone had something to do, but she seemed to be the only one who didn't. Fortunately, Artemis, Leeds' owl, sent her the lace dress she asked for.

It's just that this nightgown is made according to Professor Sprout's body shape and looks like a fishnet.

She is not good at handicrafts. Although she can do magic, magic cannot solve all problems.

She still had to find someone to correct her, otherwise she would have to learn it on her own... Then she thought of Molly, it seemed like she hadn't been to the Weasley house for a long time.

It happened that Bill's OWS test results came out, but the transcript was not sent out. He got 12 O's, the same as Barty Crouch Jr.

It seemed like she should give him a gift, what should she give him? Maybe she could sponsor him to go to Brazil as an exchange student, but in this case, who would Severus find to participate in the Potions Competition the year after next?

"Whatever." Pomona put the "fishnet" away, hoping that Molly wouldn't misunderstand. She only wore it because of the hot weather, and had no other meaning, despite the clerk's expression when he introduced those lace pajamas.

Nothing looks right.
Chapter completed!