Heavenly Coordinates and Star Maps

You can see about 6000 stars in the whole sky in the whole sky, but we only see half of them, because the other half of the starry sky closes the earth from us. Due to its rotation, the type of star sky is changing. Some stars just appear due to the horizon (go beyond) in the eastern part of it, others at this time are high above their heads, and the third are already hiding behind the horizon in the western side (enter). At the same time, it seems to us that the starry sky rotates as a whole. Now everyone is well known that the rotation of the sky - the phenomenon is apparent, caused by the rotation of the Earth. The painting that as a result of the daily rotation of the Earth occurs with the star sky, allows you to capture the camera.

If you managed to take a picture of the stars in the sky for the whole day, then the photos would be complete circles - 360 °. After all, the day is the period of full turnover of the Earth around its axis. For an hour, the land turns on 1/24 part of the circle, i.e., at 15 °. Consequently, the length of the arc, which the star describes the time will be 15 °, and for half an hour - 7.5 °. To indicate the position of the luminaries in the sky, the coordinate system is used similar to that used in geography - the system of equatorial coordinates. As you know, the position of any item on globe can be specified using geographic coordinates - latitude and longitude. The geographical longitude (φ) is counted along the equator from the initial (Greenwich) meridian, and the geographical latitude (L) - according to the meridians from the equator to the Poles of the Earth.

So, for example, Moscow has the following coordinates: 37 ° 30 "Eastern longitude and 55 ° 45" northern latitude. We introduce a system of equatorial coordinates, which indicates the position of the shone on the celestial sphere relative to each other. We will spend through the center of the heavenly area of \u200b\u200bthe line, parallel axis of rotation of the Earth, the axis of the world. It will cross the heavenly sphere in two diametrically opposite points, which are called the poles of the world - R & R. "The North Pole of the world is called the one near which the polar star is located. The plane passing through the center of the sphere parallel to the plane of the Earth's equator, in cross section with a sphere forms a circle, called heavenly equator. Heavenly equator (like the earth) divides the heavenly sphere for two hemispheres: the Northern and South. The angular distance of the shone from the heavenly equator is called a declination that is indicated by the Greek letter "Delta". The decline is counted in a circle conducted through the luminous and poles of the world, It is similar to geographic latitude.

The declination is considered positive in the shtamil, located north of the Heavenly Equator, negative - at the south. The second coordinate that indicates the position of the shone in the sky is similar to the geographical longitude. This coordinate is called direct ascent and is indicated by the Greek letter "Alpha". Direct climb is counted on the heavenly equator from the point of spring equinox, in which the sun is annually on March 21 (on the day of the spring equinox). Direct ascent is conducted in the direction opposite to the visible rotation of the heavenly sphere. Therefore, the luminaries go back (and enter) in order of increasing their direct climb. In astronomy, it is customary to express direct ascent not to a degree, but in the clock. You remember that due to the rotation of the Earth 15 ° correspond to 1C, and 1 ° - 4 minutes. Consequently, the direct climbing equal to, for example, 12 hours is 180 °, and 75 ° corresponds to 115 °. The principle of creating a star sky card is very simple. We first design all the stars on the globe: where the ray, directed to the star, cross the globe's surface, will be an image of this star.

Usually, not only stars are depicted on the star globe, but also the grid of equatorial coordinates. In fact, the star globe is the model of the heavenly sphere, which is used in the lessons of astronomy at school. There are no images of stars on this model, but the axis of the world, heavenly equator and other circles of the heavenly sphere are presented. It is not always convenient to use the star globe, so in astronomy (as in geography), maps and atlases received widespread. Map ground surface You can get if all points of the earth's globe design on the plane (the surface of the cylinder or cone). Having spent the same surgery with a star globe, you can get a map of the starry sky. Get acquainted with the simplest moving star card. We have a plane on which we want to get a map so that it concerns the surface of the globe at the point where the North Pole of the world is located. Now we need to design all the stars and the coordinate grid from the globe on this plane. Get a map like geographical cards The Arctic or Antarctic, where in the center there is one of the poles of the Earth.

In the center of our star card will be located the North Pole of the world, there is a polar star next to him, a little further than the other stars of the Small Majer, as well as the stars of the big bear and other constellations that are not far from the pole of the world. The grid of equatorial coordinates is represented on the map radially divergers from the center with rays and concentric circles. On the edge of the map against each ray, numbers are written, denoting direct climbing (from 0 to 23 hours). The beam, from which direct climb begins, passes through the point of spring equinox, indicated by the sign of the Gamma Gamma letter. The declination is counting on these rays from the circle, which depicts the heavenly equator and has the designation of 0 °. The remaining circles also have a digitization that shows which declination has an object located on this circle. Depending on the star magnitude, the star is depicted on a map with circles of various diameters. Those of them that form the characteristic figures of constellations are connected by solid lines. The boundaries of constellations are denoted by dotted line.

nice hourly measures of angles should not be mixed with the same name and designation by units of time, since the angles and intervals are heterogeneous values. The hourly measure of the corners has simple ratios with a degree:

	corresponds to 15 °;		1 ° corresponds to 4sh;
\\ T.
						1 / 15s.
For translate		values				hourly measure B.

degree I.	tables exist back (Table V in
Aue or adj.	1 of this book).
Geographic			coordinates		sometimes called
ilomic					definitions.
§ 2. Equatorial coordinates of Luminous
Position		heavenly Tel		convenient to determine

vatorial coordinate system. Imagine that

sky is			huge			sphere, in the center of which is
for the sphere, we can
build slightly
coordinate
			parallel
globe. If
portrait through North
before intersection with imaginary
		heavenly
then the diametrical
	opposite
ki northern p and south
turns out
is an		geometric axis						equatorial
	coordinates. Continuing the land plane

ra, until she cross the heavenly sphere, we get on the sphere of the Heavenly Equator line.

Earth rotates around its axis from the West on

stock, and its full turn is one day. The observer on Earth seems that the heavenly sphere with

all visible luminaire rotates
in the opposite	direction, i.e. from the east
west. It seems to us that the sun is daily
around the earth: in the morning it		rises		eastern
part of the horizon, and			over the horizon

west. In the future, we will consider instead of the actual rotation of the Earth around the axis the daily rotation of the heavenly sphere. It occurs along the clockwise arrow, if you look from the North Pole of the World.

Particularly imagine the celestial scope is easier if you look. On the outside, as shown in Fig. 2. In addition, it shows a trace of crossing the plane of the earth orbit, or the plane of the ecliptic, with the heavenly sphere. The land makes a full turn in orbit around the Sun in one year. The reflection of this one-time treatment is the visible annual movement of the sun on the celestial sphere in the same plane, i.e., according to the ecliptic j f jl - f j t. Each day the sun moves among the stars by ecliptic to the east of about one degree arc, making a complete revolution for the year. Ecliptic intersects with a heavenly equator in two diametrically opposite points ,.named equinoxpoints: T - the point of spring equinox and - - the point of autumn equinox. When the sun happens at these points, it goes back everywhere on Earth exactly in the East, it comes exactly in the West, and the day and night are 12 hours. Such days are called equinoxies, and they come on March 21 and September 23 with a deviation from these dates Less than one day.

The planes of geographic meridia-new, continued before the intersection of the E celestial sphere, form heavenly meridians in the intersection. Heavenly meridians countless. Among N. Ich, it is necessary to choose the initial similarly to how it is adopted for zero-meridian, passing through the Greenwich Observatory. For such a line of reference in astronomy, heavenly meridian, passing through the point of spring equinox, and referred to as the circulation of the point of spring equinox. Heavenly meridians passing through the locations of the position of the luminaire are called the crugs of decline in these shining,

In the equatorial coordinate system, the main circles are the heavenly equator and the shower circle of the point y. The position of any shone in this coordinate system is determined by direct ascent and decline.

PRA M M O E V O S H O H D E N E A A is a spherical angle at a pole of the world between the circle of the decline of the spring equinox and the circle of declining the shone, considered to the side opposite to the daily rotation of the heavenly sphere.

Direct climbing is measured by the arc of heavenly

nei of the celestial sphere, therefore, and does not depend on the daily rotation of the heavenly sphere.

and the direction on the luminous. It is measured by the decline in the corresponding arc of the circle of decline from the heavenly equator to the place of the shone. If the luminaire is in the northern hemisphere (north of the heavenly equator), his declination is attributed to the name N, and if in South-Name 5. When solving astronomical problems, the plus sign gives the magnitude of the decline in the same name of the observation location. In the northern hemisphere of the Earth, the northern decline is considered positive, and the southern decline is negative. The declination of the luminaire may vary from 0 to ± 90 °. The decline of each point of the heavenly equator is 0 °. The declination of the North Pole of the world is 90 °.

Any luminaire performs the full turn around the pole of the world in its daily parallel together with the heavenly sphere, therefore b, as well as, does not depend on its rotation. But if the luminaire has an additional movement (for example, the sun or planet) and moves through the celestial sphere, its equatorial coordinates change.

The values \u200b\u200bof A and B are attributed to the observer, as if located in the center of the Earth. This allows you to use the equatorial coordinates of the shone anywhere in the land.

§ 3. Horizontal coordinate system

The center of the celestial sphere can be transferred to any

point of space.

particular

accommodate with the intersection point of the main axes

that. In such a case

tools (fig.

geometric

horizontal

coordinates.

In the intersection from heaven

sheer

forms

observer.

passing

heavenly

perpendicular-

direction

called

plane

true

horizon and in transition

surface

heavenly

true

horizon

designations

light countries adopted traditional in

transcription: N (Nord), S (South), W (West)

Through a sheer line you can spend

countless

many set

vertical

planes. In the intersection

with surface

heavenly sphere

form

circles, called verticals. Any vertical

the luminous location is called the vertical of the shone.

		Pph.					characterization
	like a line, parallel axis of rotation
Then the plane of the celestial equator QQ \\ will paralle
	plane		earth Equator. Vertical
					PZP \\ ZX,	is an
temporary heavenly				meridian			observations
or meridian			observer. Meridian				observer

meridian observer with the plane of the true horizon is called a midday line. The nearest point of the intersection of the midday to the North Pole

through the points of the East and the West, they call the first vertical. Its plane is perpendicular to the plane of the supervisor meridian. Heavenly sphere is usually

				plane Meridiana				observer
coincides with the drawing plane.
The main coordinate circles in the horizontal
the system serve the true horizon and							meridian
dutcher. First of these circles							the system received
your name.		Coordinates
	are				and zenitite		distance.
And s and m u t		with in e t and l a			A - spherical
point of Zenith between the Meridian of the Observer
				astronomy				count
					meridiana		observer, but

since ultimately, astronomical azimuths of directions are determined for geodetic purposes, it is more convenient to take a geodesic account of azimuth in this book. They are measured by arcs of the true horizon from the point of the North to the vertical shone along the way

the center between the direction in Zenith and the direction on the shining. The anti-aircraft distance is measured by the vertical arc shone from the point of the zenith to the place of the shone. The anti-aircraft distance always positively and changes the value from 0 to 180 °.

The rotation of the Earth around its axis from the west to the East causes the visible daily rotation of the shone around the pole of the world together with all the heavenly sphere. it

- Explanation - Ideally, work is performed in the computer training program IISS "Planetarium"

Without this program, you can perform the work using a mobile card of the starry sky: a map and an overhead circle.

Practical work with mobile card
star sky.

Subject . Visible movement of the sun

Objectives lesson .

Students should be able to:

1. Determine the equatorial coordinates on the map shining and, on the contrary, knowing the coordinates to find the shine and determine its name on the table;

2. Knowing the equatorial coordinates of the Sun, determining its position on the celestial sphere;

3. Determine the time of sunrise and sunset, as well as the time of stay above the horizon of stars and the sun;

4. Calculate the height of the shone above the horizon in the upper climax, knowing the geographical latitude of the place of observation and determining its equatorial coordinates on the map; Solve the opposite task.

5. Determine the declination of the shone, which do not yield or do not enter the observation location.

Basic concepts. Equatorial and horizontal coordinate system.

Demonstration material. Movable map of the starry sky. Planetarium. Illustration.

Independent activities of students. Perform the tasks using an electronic planetarium and a movable map of the starry sky.

The ideological aspect of the lesson. Formation scientific approach to the study of the world.

5. What shows the sign of declining?

6. What is equal to the declination of points lying on the equator?

Find concentric circles on the map, the center of which coincides with the North Pole of the world. These circles are parallels, i.e., the geometric location of points having the same declination. The first circle from the equator has an incidence of 30 °, the second - 60 °. The declination is counted from the heavenly equator if to the north pole, then δ\u003e 0; If south of the equator, then δ< 0.

For example, find A Capel. It is in the middle between parallels of 30 ° and 60 °, which means it is approximately 45 °.

Radial lines on the map correspond to crugs of declination. To determine the direct climb of the shone, you need to determine the angle from the point of spring equinox to the displacement circle passing through this shone. To do this, connect the North Pole of the world and shone the straight line and continue it to intersee with the inner boundary of the card, on which the clock is indicated, this is direct climbing the shine.

For example, we connect a chapel with the North Pole of the world, we continue this line to the inner edge of the map - about 5 hours 10 minutes.

Task students.

Determine the equatorial coordinates of the shine and, on the contrary, according to the coordinates, I will find the shine. Check yourself using an electronic planetarium.

1. Determine the coordinates of stars:

1. a. Lion.	BUT)a. \u003d 5h13m,d. \u003d 45 °
2. a. Easy	B)a. \u003d 7h37m,d. \u003d 5 °
3. a. Small Psa.	IN)a. \u003d 19ch50min,d. \u003d 8 °
4. a. Eagle	D)a. \u003d 10h,d. \u003d 12 °
	E)a. \u003d 5h12min,d. \u003d -8 °
	E)a. \u003d 7ch42min,d. \u003d 28 °

2. By approximate coordinates, determine which stars:

1. a. \u003d 5h 12min,d. \u003d -8 °	BUT)a. Easy
2. a. \u003d 7h 31min,d. \u003d 32 °	B)b. Orion
3. a. \u003d 5h 52min,d. \u003d 7 °	IN)a. Twins
4. a. \u003d 4h 32min,d. \u003d 16 °	D)a. Small Psa.
	E)a. Orion
	E)a. Tales

3. Determine the equatorial coordinates and in which constellations are:

To perform the following tasks, recall how to determine the position of the Sun. It is clear that the sun is always on the ecliptic line. Connect the calendar date of the straight line with the center of the map and the intersection point of this line with the ecliptic and is the position of the sun at noon.

Task students.

Option 1

4. Equatorial coordinates of the Sun A \u003d 15 h, d \u003d -15 °. Determine the calendar date and constellation in which the sun is located.

BUT)a. \u003d 21 h,d. \u003d 0 ° b)a. \u003d -15 °,d. \u003d 21 h c)a. \u003d 21 h,d. \u003d -15 °

6. Direct sunshine a \u003d 10h 4 min. What is the bright star on this day near the sun?

BUT)a. Sextant b)a. Hydra B)a. Lion.

To determine which luminaries are located above the horizon at this time, you need to put a movable circle on the map. Align the time specified on the edge of the mobile circle with the calendar date marked on the edge of the map, and the constellation that you see in the "window" you will see above the horizon at this time.

During the day, the celestial sphere makes a complete turn from east to the west, and the horizon does not change its position regarding the observer. If you rotate the invoice clockwise clockwise, imitating the daily rotation of the heavenly sphere, then we note that some luminaries go beyond the horizon, while others come. Rotating the invoice clockwise, notice the position of the circle when Aldebaran only appeared above the horizon. Look at what time marked on the overhead circle corresponds to the desired date, it will be the desired time of sunrise. Determine which side of the horizon is treated Aldebaran. Similarly, determine the time and location of the star and calculate the duration of the stay of the shone above the horizon.

Task students.

7. Which of the constellations that crosses the ecliptic are above the horizon in our latitudes at the time of 22 hours of June 25?

A) eagle b) snakeco c) lion

8. Determine the sunrise time and sunset, duration of the day

9. Determine the sunrise and sunset time, the duration of the day

Remember the relation that, knowing the equatorial coordinates of the shining, can be calculated the height of the shone in the upper climax. Consider the task. We write the condition: the latitude of Moscow J \u003d 55 °; Since the date is known - March 21 - the day of the spring equinox, we can determine the decline of the Sun - D \u003d 0 °.

Issues of students.

1. South or north of Zenith cultures the sun? (T. K.d. < j., the sun is culting south).

2. What formula to calculate the height should be used?

3. (h \u003d Δ + (90˚ - φ)

4. Calculate the height of the sun. H \u003d 0 ° + 90 ° - 55 ° \u003d 35 °

Task students. With the help of an electronic planetarium, determine the equatorial coordinates of the shining and check the correctness of the problem.

1. At what height is the sun at noon 22.12 on the latitude of Moscow 55 °?

2. What is the height of the lips in the upper climax for Chisinau (j \u003d 47 ° 2`)?

3. What latitude of Vega cultures in the zenith?

4. What condition should the sunsunity of the sun shall be satisfied so that at noon on this latitude j, the sun passed through Zenit?

Nodal Questions: 1. The concept of constellation. 2. Difference of the stars in brightness (luminosity), color. 3. Star magnitude. 4. Visible daily movement of stars. 5. Heavenly sphere, its main points, lines, planes. 6. Star card. 7. Equatorial SC.

Demonstrations and TSO: 1. Demonstration mobile map of the sky. 2. Model of the heavenly sphere. 3. Star Atlas. 4. Diaposes, photographs of constellations. 5. Model of the heavenly sphere, geographical and star globes.

For the first time, the stars were indicated by the letters of the Greek alphabet. In the constellation of the Atlas Baigera in the XVIII century, the patterns of constellations disappeared. The map indicates stellar values.

Big Mesman - (Duzhe), (Merak), (Fef), (Metritz), (Aliot), (Mitsar), (Benetash).

Lyra - Vega, Lebedev - Denief, Volopasa - Arcturus, Valley - Capella, B. Psa - Sirius.

The sun, the moon and the planet on the maps are not specified. The path of the sun is shown on the ecliptic of Roman numbers. On the star maps there is a grid of celestial coordinates. The observed daily rotation is the phenomenon of apparent - caused by the actual rotation of the Earth from the west to the East.

Earth proof of rotation:

1) 1851 Fouco Physicist - Fouco's pendulum - length 67 m.

2) Space satellites, photos.

Celestial sphere - Imaginary sphere of an arbitrary radius used in astronomy to describe the mutual position luminaries in the sky. Radius is taken for 1 PC.

88 constellations, 12 zodiacal. Conditionally can be divided into:

1) Summer - Lira, Swan, Eagle 2) Autumn - Pegasus with Andromeda, Cassiopeia 3) Winter - Orion, B. Dog, M. Dog 4) Spring - Virgin, Volfa, Lion.

Sheer line Crosses the surface of the heavenly sphere in two points: in the upper Z. - zenit - and in the bottom Z." - nadird.

Mathematical horizon - a large circle on the celestial sphere whose plane is perpendicular to the sheer line.

Point N. The mathematical horizon is called point of north, point S. - point of south. Line NS. - called midday line.

Heavenly Equator It is called a large circle, perpendicular axis of the world. Heavenly Equator intersects with a mathematical horizon in points of East E. and west W..

Heaven meridian called a big circle of heavenly sphere passing through zenith Z., Pole Mira R, South Pole R", Nadir Z.".

Homework: § 2.

Constellations. Star cards. Heavenly coordinates.

1. Describe what daily circles would be described by stars if astronomical observations were carried out: on the North Pole; At the equator.

The visible movement of all stars occurs in a circle parallel to the horizon. The North Pole of the world when observing the North Pole of the Earth is in Zenith.

All stars rise in right corners to the horizon in the eastern sky and also go beyond the horizon in Western. The heavenly sphere rotates around the axis passing through the poles of the world, at the equator located exactly on the horizon line.

2. Express 10 h 25 min 16 s to degree.

The land in 24 hours makes one turn - 360 oh. Consequently, 360 o corresponds to 24 hours, then 15 o - 1 h, 1 o - 4 min, 15 / - 1 min, 15 // - 1 s. In this way,

1015 o + 2515 / + 1615 // \u003d 150 o + 375 / +240 / \u003d 150 o + 6 o +15 / +4 / \u003d 156 o 19 /.

3. Determine the Equatorial coordinates of Vigi on the star map.

I will replace the name of the star with alphabetic designation (lira) and find its position on the star map. Through an imaginary point, we carry out a circle of declining to the intersection with the Heavenly Equator. The arc of the Heavenly Equator, which lies between the point of spring equinox and the point of intersection of the circle of the decline of the star with the heavenly equator, is a direct climbing of this star, counted along the heavenly equator to meet the visible daily handling of the heavenly sphere. The angular distance, counted in a circle of decline from the heavenly equator to the star, corresponds to the decline. Thus, \u003d 18 h 35 m, \u003d 38 o.

The invoice of the star card turns so that the stars crossed the eastern part of the horizon. On the limb, opposite the mark on December 22, we find the local time to go. Having a star in the western part of the horizon, we define the local start time of the star. Receive

5. Determine the date of the upper climax of the star regult at 21 h local time.

We establish an overhead circle so that the star can (lion) be on the heavenly meridian line (0 h. - 12 h. Scale of the overhead circle) south from the North Pole. At the limb of the overhead circle, we find a mark 21 and opposite it on the edge of the overhead circle we define the date - April 10.

6. Calculate how many times Sirius is brighter Polar stars.

It is believed that with a difference in one star magnitude, the visible brightness of the stars differs by about 2.512 times. Then the difference in 5 star magnitudes will be a distinction in brightness exactly 100 times. So the stars of the 1st magnitude 100 times brighter than the stars of the 6th magnitude. Consequently, the difference between the visible star magnitudes of two sources is equal to one, when one of them brighter than the other in (this value is approximately equal to 2.512). In general, the attitude of the visible brightness of two stars is associated with the difference between their visible stellar magnitudes by simple ratio:

Luminous, the brightness of which exceeds the brightness of the stars 1 m. , have zero and negative stellar values.

Sirius star magnitudes m. 1 \u003d -1.6 and polar stars m. 2 \u003d 2.1, we find in the table.

Progrigimize both parts of the specified ratio above:

In this way, . From here. That is, Sirius brighter a polar star is 30 times.

Note: Using power function, I also get an answer to the question of the task.

7. What do you think it is possible to fly on a rocket to any constellation?

The constellation is a conditionally defined section of the sky, within which the luminaries were from us at different distances. Therefore, the expression "fly to constellation" is deprived of meaning.

Note:

1. (Alpha Big PSA ; α CMA, Sirius). The brightest star in the constellation of Big Psa and the brightest star in the sky. This is a visual-double star with a period of circulation of 50 years, the main component of which is a (a) is a star, and the second component (B, puppy) is a white dwarf of the 8th Star magnitude. Sirius B was optically discovered in 1862, and its type was determined on the spectrum in 1925. Sirius is removed from us at a distance of 8.7 light years and proximity to Solar system It takes the seventh place. The name is inherited from the ancient Greeks and means "Clearing", which emphasizes the shine of the star. In connection with the name of the constellation, to which Sirius belongs, he is also called the "dog star". The third star, brown dwarf, closer to (a) than the component (B), opened by French astronomers in 1995.
2. (Alpha Volcasa, α Boo, Arctur.). The brightest star in the constellation of Volopasses, an orange giant, K-star, the fourth star brightness in the sky. Double, variable. Title has greek origin And means "Bear's watchman." Arcturus was the first star, which was able to see the day with the help of a telescope to the French astronomer and astrologer MOREOR in 1635.
3. (Alpha Lira; α LYR, Vega). The brightest star in the constellation Lyra and the fifth brightness of the star in the sky. This is a star. In 2005, the space telescope "Spitzer" were obtained images of the vegue, as well as the surrounding dust star in the infrared spectrum. A planetary system is formed around the star.
4. (Alpha Vay; α AUR, Capella). The brightest star in the constellation of the erection, spectral-double star, in which the main component is a giant G-star. Her name of Latin origin and means a "little goat".
5. (Beta Orion.; β ori Rigel). The brightest star in the constellation Orion. For its designation, the Greek letter beta is used, although it is a little brighter Bethelgeuse marked as Alpha Orion. Rigel is a supergiant, a B-star with a compartion of the 7th Star magnitude. The name having arabic origin means "Giant's foot".
6. (Alpha Small Psa.; α cmi, PERSON). The brightest star in the constellation of small dogs. The priest takes the fifth place among all stars. In 1896, J. M. Sheberl discovered that the probe is a double system. The main companion is a normal F-star, and a weak companion is a white dwarf of the 11th Star magnitude. The system of circulation of the system is 41 years. The name of the probe has a Greek origin and means "in front of the dog" (reminder that the star goes back to the "dog star", i.e. Sirius).
7. (Alpha Orla; α AQL, Altair). The brightest star in the constellation of the Eagle. Arab word "Altair" means "flying eagle." Altair - A-Star. This is one of the closest among the most bright stars (located at a distance of 17 light years).
8. (Alpha Orion.; α ori Bethelgeuse). Red supergiant, M-star, one of the biggest famous stars. Through point interferometry and other interference methods, it was possible to measure its diameter, which turned out to be approximately 1000 diameters of the Sun. The presence of large bright "star spots" was discovered. Ultraviolet observations carried out using Space telescope Hubble, showed that Bethelgeuse is surrounded by an extensive chromosphere, the mass of which is approximately twenty solar. Variable. Brightness is irregularly changing between 0.4 and 0.9 values \u200b\u200bwith a period of about five years. Notable is the fact that during the observation from 1993 to 2009, the stars diameter decreased by 15%, with 5.5 astronomical units up to about 4.7, and astronomers can not yet explain what it is connected with. At the same time, the brightness of the star did not change any noticeable during this time.
9. (Alpha Tales; α tau, Aldebaran.). The brightest star in the Constellation of the Taurus. Arabic name means "next" (that is, coming after the Pleiades). Aldebaran is a giant K-star. Variable. Although the star in the sky looks part of the accumulation of Hiad, in fact she is not his member, being twice as close to the ground. In 1997, a possible existence of a satellite is a large planet (or small brown dwarf), with a massive of 11 masses of Jupiter at a distance of 1.35 AE. Unmanned spacecraft Pioneer-10 heads towards Aldebaran. If nothing happens to him along the way, it will reach the stars area around 2 million years.
10. (Alpha Scorpion.; α SCO, Antares). The brightest star in the constellation of Scorpio. Red supergigant, M-star, variable, the double name has a Greek origin and means "Mars Competitor", which reminds of the wonderful color of this star. Antares-half-speaking variable, the brightness of which changes between the stellar values \u200b\u200bof 0.9 and 1.1 with a five-year period. It has a blue star of the 6th Star magnitude, removed by only 3 arc seconds. Antares in was opened during one of these coverage on April 13, 1819. Satellite circulation period - 878 years.
11. (Alpha Virgin; α vir Spika). The brightest star in the constellation of the Virgin. This is an eclipse double, variable whose brightness changes by about 0.1 star magnitude with a period of 4,014 days. The main component is a white-blue B-star with a mass of about eleven mass of the sun. The name means "corn bye".
12. (Beta twins; β gem Pollux). The brightest star in the constellation of twins, although its designation is beta, not alpha. It seems unlikely that Pollux since the time of Bayer (1572-1625) became brighter. Pollux is an orange giant, K-star. In the classic mythology, the twins Kastor and Pollux were sons of ice. In 2006, the star was found an exoplanet.
13. (Alpha South Fish; α psa,
14. (Epsilon of Big Psa.; ε CMA, Adara). The second brightness (after Sirius) Star in the constellation of a large dog, a giant B-star. Has a post-companion 7.5 m. The Arabic name of the star means "Virgin". Approximately 4.7 million years ago, the distance from ε large ps to the ground was 34 light years, and the star was brightest in the sky, its shine was equal to -4.0 m
15. (Alpha Genetov; α gem Castor). The second brightness in the constellation of twins after Pulux. Its stellar value when observed with the naked eye is estimated as 1.6, but this is the combined brightness of the multiple system consisting of at least six components. There are two A-stars with star values \u200b\u200b2.0 and 2.9, forming a close visual couple, each of which is spectral-double, and a more distant red star of the 9th Star magnitude, which is the eclipse double.
16. (Gamma Orion.; γ ORI, Bellatrix.). Giant, B-star, variable, double. The name has a Latin origin and means "Woman Warring". One of the 57 antiquity navigation stars
17. (Beta Tales; β tau, NAT). The second in brightness in the Constellation of the Taurus, lying on the edge of one of the bull horns. The name comes from the Arabic expression "Boding horns." This star on vintage maps portrayed the right leg of the human figure in the constellation of the ease and had a different designation, the gamma of the ease. ELNAT - B-star.
18. (Epsilon Orion; ε Ori Alnim). One of the three bright stars forming an Orion belt. Arabic name is translated as "pearl thread." Alnim - supergiant, in-star, variable
19. (Dzeta Orion.; ζ ori Alnito.). One of the three bright stars forming an Orion belt. Arabic name is translated as a "belt". Alnitiat - Supergiant, O Star, Triple Star.
20. (Epsilon Big Mesmen.; ε uma, Alieot.). The brightest star in the constellation is a big bear. Greek letters in this case are fixed behind the stars in the order of their position, and not brightness. Aliot - A-Star, maybe it has a planet 15 times a massive Jupiter.
21. (Alpha Big Mesmen.; α uma, Dubhe). One of the two stars (second is a merate) of a large bucket in a big bear, called pointers. Giant, K-star, variable. The 5th Star Moist companion revolves around it with a period of 44 years. DUKKH, literally "bear", is a reduced version of the Arab name, meaning the "back of a larger bear."
22. (Alpha Persea; α per, Miraph). The brightest star in the Perseus constellation. Yellow supergigant, f-star, variable. The name, Arabic origin means "elbow".
23. (This big bear; η uma, Benetnash). Star located at the end of the "tail". B-star, variable. Arabic name means "head of the plasters" (for Arabs the constellation was seen like a catatball, not a bear).
24. (Beta big dog; β CMA, Mirzam). The second in brightness in the constellation of large dogs. Giant B-star, variable, is a prototype class of weak variable stars type Beta Beta PSA. Its brightness varies every six hours for several hundredths of the stellar value. Such a low level of variability is not detected by the naked eye.
25. (Alpha Hydra; α hya, Alphard.). The brightest star in the constellation Hydra. The name of Arabic origin means "the retired snake." Alphard - K-star, variable, triple.
26. (Alpha Malaya Medveditsa; α UMI, Polar). The brightest star in the constellation of a small bear, located near the Northern Heavenly Pole (at a distance of less than one degree). Polar is the nearest to the ground with a pulsating variable star type Tsfhey type with a period of 3.97 days. But the polar is a very non-standard cefeta: her pulsations are fucked during the order of the tens of years: in 1900, the change in brightness was ± 8%, and in 2005 - approximately 2%. In addition, during this time, the star became on average 15% brighter.