Presentation for the lesson - research on astronomy "our galaxy - the milky way." Presentation on the topic “The Milky Way is our galaxy Our galaxy Milky Way presentation

amazingly beautiful and bright. There are many brightly glowing star clouds in the constellations Sagittarius, Scorpio, and Scutum. It is in this direction that the center of our Galaxy is located. In this same part of the Milky Way, dark clouds of cosmic dust - dark nebulae - stand out especially clearly. If these dark, opaque nebulae were not present, the Milky Way towards the center of the Galaxy would be a thousand times brighter. Looking at the Milky Way, it is not easy to imagine that it consists of many stars indistinguishable to the naked eye. But people figured this out a long time ago. One of these guesses is attributed to the scientist and philosopher of Ancient Greece, Democritus. He lived almost two thousand years earlier than Galileo, who first proved the stellar nature of the Milky Way based on telescope observations. In his famous “Starry Messenger” in 1609, Galileo wrote: “I turned to the observation of the essence or substance of the Milky Way, and with the help of a telescope it turned out to be possible to make it so accessible to our vision that all disputes fell silent by themselves thanks to the clarity and evidence that I am freed from a long-winded debate. In fact, the Milky Way is nothing more than a countless number of stars, as if located in heaps, no matter what area the telescope is pointed at, a huge number of stars now become visible, many of which are quite bright and quite visible, but the number weaker stars cannot be counted at all.” What relation do the stars of the Milky Way have to the only star in the solar system, our Sun? The answer is now generally known. The Sun is one of the stars of our Galaxy, the Milky Way Galaxy. What place does the Sun occupy in the Milky Way? Already from the fact that the Milky Way encircles our sky in a large circle, scientists have concluded that the Sun is located near the main plane of the Milky Way. In order to get a more accurate idea of the position of the Sun in the Milky Way, and then to imagine what the shape of our Galaxy is in space, astronomers (V. Herschel, V. Ya. Struve, etc.) used the method of star counts. The point is that in different parts of the sky the number of stars in a successive interval of stellar magnitudes is counted. If we assume that the luminosities of the stars are the same, then from the observed brightness we can judge the distances to the stars, then, assuming that the stars are evenly distributed in space, we consider the number of stars that are in spherical volumes with the center in the Sun.

The work was completed by a student of grade 7 (11)-B of the Pervomaiskaya gymnasium Klimenko Daria

Our Galaxy is a star system in which the Solar System is immersed, called the Milky Way. The Milky Way is a grandiose cluster of stars, visible in the sky as a light, foggy stripe.
In our Galaxy - the Milky Way - there are more than 200 billion stars of very different luminosity and color.
OUR GALAXY - THE MILKY WAY

MILKY WAY, a hazy glow in the night sky from the billions of stars in our Galaxy. The Milky Way band encircles the sky in a wide ring. The Milky Way is especially visible away from city lights. In the Northern Hemisphere, it is convenient to observe it around midnight in July, at 10 pm in August or at 8 pm in September, when the Northern Cross of the Cygnus constellation is near the zenith. As we follow the Milky Way's shimmering streak north or northeast, we pass the W-shaped constellation Cassiopeia and head toward the bright star Capella. Beyond the Chapel, you can see how the less wide and bright part of the Milky Way passes just east of Orion's Belt and leans toward the horizon not far from Sirius, the brightest star in the sky. The brightest part of the Milky Way is visible to the south or southwest at times when the Northern Cross is overhead. At the same time, two branches of the Milky Way are visible, separated by a dark gap. The Scutum Cloud, which E. Barnard called “the jewel of the Milky Way,” is located halfway to the zenith, and below are the magnificent constellations Sagittarius and Scorpius.

What does the Galaxy consist of?
In 1609, when the great Italian Galileo Galilei was the first to point a telescope into the sky, he immediately made a great discovery: he figured out what the Milky Way was. Using a primitive telescope, Galileo was able to separate the brightest clouds of the Milky Way into individual stars. But behind them he discovered new, dimmer clouds, the mystery of which he could no longer solve with his primitive telescope. But Galileo correctly concluded that these faintly luminous clouds visible through his telescope must also consist of stars.
The Milky Way, which we call our Galaxy, is actually made up of approximately 200 billion stars. And the Sun with its planets is only one of them. Moreover, our Solar system is not located in the center of the Milky Way, but is located approximately two-thirds of its radius from it. We live on the outskirts of our Galaxy.
The Horsehead Nebula is a cold cloud of gas and dust that obscures the stars and galaxies behind it.

The Milky Way encircles the celestial sphere in a great circle. Residents of the Northern Hemisphere of the Earth, on autumn evenings, manage to see that part of the Milky Way that passes through Cassiopeia, Cepheus, Cygnus, Eagle and Sagittarius, and in the morning other constellations appear. In the Southern Hemisphere of the Earth, the Milky Way extends from the constellation Sagittarius to the constellations Scorpio, Compass, Centaurus, Southern Cross, Carina, Sagittarius.

There are many legends telling about the origin of the Milky Way. Two similar ancient Greek myths deserve special attention, which reveal the etymology of the word Galaxias and its connection with milk. One of the legends tells about the mother’s milk spilling across the sky from the goddess Hera, who was breastfeeding Hercules. When Hera found out that the baby she was breastfeeding was not her own child, but the illegitimate son of Zeus and an earthly woman, she pushed him away and the spilled milk became the Milky Way. Another legend says that the spilled milk is the milk of Rhea, the wife of Kronos, and the baby was Zeus himself. Kronos devoured his children because it was foretold that he would be dethroned from the top of the Pantheon by his own son. Rhea hatched a plan to save her sixth son, the newborn Zeus. She wrapped a stone in baby clothes and slipped it to Kronos. Kronos asked her to feed her son one more time before he swallowed him. The milk spilled from Rhea's breast onto a bare rock later became known as the Milky Way.
Legend…

Milky Way system
The Milky Way system is a vast star system (galaxy) to which the Sun belongs. The Milky Way system consists of many stars of various types, as well as star clusters and associations, gas and dust nebulae, and individual atoms and particles scattered in interstellar space. Most of them occupy a lens-shaped volume with a diameter of about 100,000 and a thickness of about 12,000 light years. The smaller part fills an almost spherical volume with a radius of about 50,000 light years. All components of the Galaxy are connected into a single dynamic system, rotating around a minor axis of symmetry. The center of the System is in the direction of the constellation Sagittarius.

Heart of the Milky Way
Scientists managed to look at the heart of our galaxy. Using the Chandra Space Telescope, a mosaic image was compiled that covers a distance of 400 by 900 light years. On it, scientists saw a place where stars die and are reborn with amazing frequency. In addition, more than a thousand new X-ray sources have been discovered in this sector. Most X-rays do not penetrate beyond the Earth's atmosphere, so such observations can only be made using space telescopes. When dying, stars leave clouds of gas and dust that are squeezed out of the center and, cooling, move to distant zones of the galaxy. This cosmic dust contains the entire spectrum of elements, including those that are the builders of our body. So we are literally made of star ash.

There are many space objects that we can see - these are stars, nebulae, planets. But most of the Universe is invisible. For example, black holes. A black hole is the core of a massive star whose density and gravitational force have increased so much after a supernova explosion that not even light can escape from its surface. Therefore, no one has yet been able to see black holes. Theoretical astronomy is still studying these objects. However, many scientists are convinced of the existence of black holes. They believe that there are more than 100 million of them in our Galaxy alone, and each of them is the remnant of a giant star that exploded in the distant past. The mass of the black hole must be colossal, many times greater than the mass of the Sun, since it absorbs everything that is nearby: interstellar gas and any other cosmic matter. According to astronomers, most of the mass of the Universe is hidden in black holes. Their existence is still evidenced only by X-ray radiation observed in some places in space, where nothing can be seen either with an optical or radio telescope.
What is a black hole?

Our Galaxy Milky Way

Vera Viktorovna Ryzhakova, physics teacher, MOAU Secondary School No. 1, Shimanovsk, Amur Region

Problematic question

What happens when two galaxies collide?
What happens when two galaxies collide?
What happens when two galaxies collide?
What happens when two galaxies collide?
What happens when two galaxies collide?
What happens when two galaxies collide?

Hypotheses

They will disperse without noticing each other
Will merge into one new one
They will explode and fly in different directions

Object of study

Galaxy

Tasks

Find out the structure of our Galaxy
Find out the size of the Milky Way galaxy
Consider the movement of stars and the Galaxy as a whole
Answer a problematic question

Information sources

Textbook B.A. Vorontsov-Velyamov, E.K. Strout “Astronomy 11th grade basic level”, Bustard, 2014, Paragraph 25, pp. 171-187
Internet astrogalaxy.ru/151.html Our Galaxy. Our Galaxy is the stellar house in which we live.
Video https://www.youtube.com/watch?v=ZdF2wX5GfdU (4.08 min)

https://www.youtube.com/watch?v=DGvvEPBtPCI (1.17 min)
Lesson route sheet

Milky galaxy,
in which we live
Scattered into space
Sparkling rain.
We can fly around
her someday
Calling our Galaxy
We're just...

Working in a notebook

Characteristic

Graphic image

Projection of the Galaxy onto the celestial sphere (view of the galaxy from Earth)

Model of the structure of the Galaxy (side view) indicating the sizes and dominant celestial bodies in each of the structural components

Model of the structure of the Galaxy (view of the galactic disk from above) with an image of spatial structural components and an indication of the position of the Sun

star cluster

Cluster name

Example, location in the galaxy

Globular clusters

Stellar "population"

Open clusters

Cluster age

Star associations

Number of stars in the cluster

Special

ness

Main conclusions

- stars do not form alone, but in groups;
- the star formation process continues to this day;
- the evolution of the Galaxy - the history of the star formation process in it;
the stars are moving

Methods for detecting features of the motion of stars

- comparison of the appearance of the constellation in different periods of time, distant from each other;
- photographic comparison of areas of the starry sky using the same telescope at intervals of time;
- study of radial velocity, which is determined by the displacement of lines in the star’s spectrum (by the Doppler effect).

S/R Clause 25, paragraph 4

1 . Where is the Sun located in the Galaxy and what are the features of the radial velocities of stars relative to the Sun?

2. Define the concept of “star apex”. In what direction is the apex of the Sun located?

3. What is the period of revolution of the Sun around the center of the Galaxy?

4. Formulate a definition of the concept “corotation circle”. What is the advantage of the position of the Solar System in the Galaxy?

conclusions- the galactic disk rotates; - the rotation period is different for different distances from the center, the Galaxy does not rotate like a rigid body; - the linear speed with distance from the center first increases quickly, then at a very large distance it remains constant and even increases

Work with computer

1. Watch the video

“Collision of the Milky Way and Andromeda Galaxies” https://www.youtube.com/watch?v=DGvvEPBtPCI (1.17 min)

2. Answer the problem question

Homework

§ 25.1, 25.2, 25.4; practical tasks.

With what angular diameter will our Galaxy, whose diameter is 0.03 Mpc, be visible to an observer located in the M31 galaxy (Andromeda nebula) at a distance of 600 kpc?
2. Using a moving star chart, determine which constellations the Milky Way passes through.

Project topics (by groups) 1. History of exploration of the Galaxy. 2. Legends of the peoples of the world, characterizing the Milky Way visible in the sky. 3. Discovery of the “island” structure of the Universe by V. Ya. Struve. 4. Model of the Galaxy by V. Herschel. 5. The mystery of the hidden mass. 6 Experiments to detect Weakly Interactive Massive Particles - weakly interacting massive particles. 7. Study by B. A. Vorontsov-Velyaminov and R. Trumpler of interstellar absorption of light. Internet resources http://www.youtube.com/watch?v=_sQD0Fbr FCw - Our Galaxy. Milky Way. http://www.youtube.com/watch?v=99PR9HSDp BI - Our Galaxy. View from the outside.

Slide 2

The Milky Way is the galaxy that contains the Earth, the solar system, and all the individual stars visible to the naked eye. Refers to barred spiral galaxies. The Milky Way, together with the Andromeda Galaxy (M31), the Triangulum Galaxy (M33), and more than 40 small satellite galaxies of it and Andromeda form the Local Group of galaxies, which is part of the Local Supercluster (Virgo Supercluster).

Slide 3

Etymology The name Milky Way is a tracing paper from Lat. vialactea “milk road”, which, in turn, is a translation from ancient Greek. ϰύϰλος γαλαξίας “milk circle”. According to ancient Greek legend, Zeus decided to make his son Hercules, born from a mortal woman, immortal, and for this he planted it on his sleeping wife Hera so that Hercules would drink divine milk. Hera, waking up, saw that she was not feeding her child, and pushed him away from her. The stream of milk that splashed from the goddess’s breast turned into the Milky Way. In the Soviet astronomical school, the Milky Way was simply called “our Galaxy” or “the Milky Way system”; The phrase "Milky Way" was used to refer to the visible stars that optically constitute the Milky Way to an observer.

Slide 4

Structure of the Galaxy The diameter of the Galaxy is about 30 thousand parsecs (about 100,000 light years, 1 quintillion kilometers) with an estimated average thickness of about 1000 light years. The galaxy contains, according to the lowest estimate, about 200 billion stars (modern estimates range from 200 to 400 billion). The bulk of stars are located in the shape of a flat disk. As of January 2009, the mass of the Galaxy is estimated at 3·1012 solar masses, or 6·1042 kg. The new minimum estimate puts the galaxy's mass at just 5·1011 solar masses. Most of the Galaxy's mass is contained not in stars and interstellar gas, but in a non-luminous halo of dark matter.

Slide 5

Disk Scientists estimate that the galactic disk, which protrudes in different directions in the region of the galactic center, has a diameter of about 100,000 light years. Compared to a halo, the disk rotates noticeably faster. The speed of its rotation is not the same at different distances from the center.

Slide 6

Core In the middle part of the Galaxy there is a thickening called the bulge, which is about 8 thousand parsecs in diameter. The center of the Galaxy's core is located in the constellation Sagittarius (α = 265°, δ = −29°). The distance from the Sun to the center of the Galaxy is 8.5 kiloparsecs (2.62·1017 km, or 27,700 light years). In the center of the Galaxy, there appears to be a supermassive black hole (Sagittarius A*) around which, presumably. The central regions of the Galaxy are characterized by a strong concentration of stars: each cubic parsec near the center contains many thousands of them. The distances between stars are tens and hundreds of times smaller than in the vicinity of the Sun. As with most other galaxies, the distribution of mass in the Milky Way is such that the orbital speed of most stars in this Galaxy does not depend significantly on their distance from the center. Further from the central bridge to the outer circle, the usual speed of rotation of stars is 210-240 km/s. Thus, such a distribution of speed, not observed in the solar system, where different orbits have significantly different speeds of rotation, is one of the prerequisites for the existence of dark matter.

Slide 7

Arms The galaxy belongs to the class of spiral galaxies, which means that the Galaxy has spiral arms located in the plane of the disk. The disk is immersed in a spherical halo, and around it is a spherical corona. The solar system is located at a distance of 8.5 thousand parsecs from the galactic center, near the plane of the Galaxy, on the inner edge of the arm called the Orion arm. This arrangement does not make it possible to observe the shape of the sleeves visually. New data from observations of molecular gas (CO) suggest that our Galaxy has two arms, starting at a bar in the inner part of the Galaxy. In addition, there are a couple more sleeves in the inner part. These arms then transform into a four-arm structure observed in the neutral hydrogen line in the outer parts of the Galaxy.

Slide 8

Halo The galactic halo has a spherical shape, extending beyond the galaxy by 5-10 thousand light years, and a temperature of about 5·105 K. The center of symmetry of the Milky Way halo coincides with the center of the galactic disk. The halo consists mainly of very old, dim, low-mass stars. They occur individually and in the form of globular clusters, which can contain up to a million stars. The age of the population of the spherical component of the Galaxy exceeds 12 billion years, it is usually considered to be the age of the Galaxy itself.

Slide 9

Evolution and future of the Galaxy Collisions of our Galaxy with other galaxies, including such a large one as the Andromeda Galaxy, are possible, but specific predictions are not yet possible due to ignorance of the transverse velocity of extragalactic objects.

Slide 10

View all slides

On Earth, a year is the time it takes for the Earth to make a full revolution around the Sun. Every 365 days we return to the same point. Our solar system revolves in the same way around a black hole located at the center of the galaxy. However, it takes 250 million years to complete a full revolution. That is, since the dinosaurs disappeared, we have only made a quarter of a full revolution. Descriptions of the solar system rarely mention that it moves through space, like everything else in our world. Relative to the center of the Milky Way, the solar system moves at a speed of 792 thousand kilometers per hour. To put things into perspective, if you were moving at the same speed, you could travel around the world in 3 minutes. The period of time during which the Sun manages to make a full revolution around the center of the Milky Way is called the galactic year. It is estimated that the Sun has lived only 18 galactic years so far.