The dragon is a rather long circumpolar constellation of the Northern Hemisphere of the sky, wide arch "embracing" the Little Bear. It occupies an area of 1083 square degrees. It has been known for a long time since the times of Ancient Greece (Eudoks Knidsky, IV century BC).
In Latin, the name of the constellation is written as Draco, abbreviated accepted designation - Dra. The constellation includes 80 stars visible to the naked eye. In the Dragon is the north pole of the ecliptic - perpendicular to the plane of our planet's orbit indicates to us a point with coordinates: Pr.voskhod. = 18 hours 00 minutes, Skl. = +66.5 degrees.
The dragon belongs to a small group of constellations, where the alpha is not the brightest star in the constellation.
On the first place on shine in a constellation, there is Gamma the Dragon carrying name Etamine that in translation from Arabic means Snake. Its shine is equal to 2.2-star size. It enters a quadrangular group of stars of the Head of the Dragon. It is an orange giant, spectral class K5, distant from us for 148 light-years. Measuring the coordinates of this star, James Bradley discovered the phenomenon of light aberration in 1725.
The Beta Dragon has a shine of 2.8 stellar magnitude. She is named Rastaban, the head of a snake. It is a yellow giant of spectral class G2. The distance from us to this star is 361 light year.
Alpha Dragon is named Tuban. This star has shine of 3,7-star size and concerns to a spectral class A0. It is a bluish-white giant from which light reaches the Earth for 309 years. Thanks to precession Alpha the Dragon was the nearest to a pole of the world star with IV in the middle of II millennium BC.
There are many double stars in the constellation
Epsilon of the Dragon with a shine of 3.8 stellar value is a close double. Its 7.4-star shine satellite will defend from the main star for 3 seconds of the arc. The main star belongs to the spectral class G8. The Epsilon of the Dragon will defend from us at a distance of 146 light-years.
This Dragon shine of 2.7 stellar magnitude (spectral class G8) is also a double star. Next to it, at a distance of about 5 seconds of arc, there is a weak star-satellite of 8.7 magnitude. The distance to Eta Dragon is equal to 88 light-years.
A very small double star for amateur instruments will seem to be My Dragon. This pair of stars with a shine of about 6 stars will be 88 light-years away from us. Both stars are separated by about 2 seconds of arc. The rotation period of the pair around the common center of masses is 670 years.
If you need large enough magnifications to observe the previous double magnification, the next star in our view is the Dragon Nu Dragon, which can be divided evenly into binoculars, and can be seen in the telescope with small magnifications. Both white stars have a shine of 4.9 stars. Light from this pair reaches the Earth in a hundred years.
16-17 The dragon is a very wide pair of bluish-white stars, which is divided evenly into binoculars. Component 17 of the Dragon, in turn, is a double with a separation of about 3 seconds. Here for supervision, the telescope with enough big magnification is required. Thus we are dealing with a triple star system. The distance from us is 400 light-years.
The triple system is also 39 Dragons. The pair of stars 5.0 (blue) and 7.4 (yellow) is visible even through binoculars.
Next to the main star, a shiny satellite of about 8 stars can be found. A telescope is already needed here. The distance to the 39th Dragon is 188 light-years.
Of the foggy objects (deep sky), a couple of noteworthy objects are available for a small telescope in the Dragon. The first is a planetary nebula with the number NGC 6543, which has the shine of the eighth stellar magnitude and bears the name "Cat's eye". It was discovered by William Herschel in 1786. It was the first planetary nebula for which the spectrum was obtained in the middle of the 19th century. It is located at a distance of 3300 light-years. It is visible in small telescopes as bluish-green disk of the wrong form in the cross-section about 20 seconds of an arch, outwardly similar to the not focused star.