(April, May, June, July, August, September and October schedule)
Draco constellation is in best position for observing on the evening sky in July, when it is close to the zenith. We will also observe it in April when is on the northeastern sky, in May when it is high on the northeastern sky, in June when it is high on the northeastern sky close to the zenith, in July when it is in best position for observing close to the zenith, in August when it is high on the northwestern sky close to the zenith, and in September and October when it is on the northwestern sky.
Double and multiple stars
17/16 Draconis - Stars 17 Draconis and 16 Draconis have visual magnitudes 5.0 and 5.5 and are separated on the sky about 90 arc seconds. Can be split even with binoculars. Their distance from Earth is about 400 light years and 430 light years respectively. But if we take into account the error in calculated distances, there is great probability that these two stars are in fact true binary star system with large distance between each other and very long orbital period.
But observed through telescope, 17 Draconis is also double star, with components with visual magnitudes of 5.4 and 6.4 and separated on the sky only about 3 arc seconds. Above mentioned visual magnitude 5.0 of 17 Draconis is the total magnitude of both stars. Both stars are 2-3 times bigger in size and with higher temperature than our Sun and are main sequence dwarfs. In reality, the distance between the components is huge, over 50 billion km and their orbital period is in thousands of years.
16 Draconis is also 2-3 times bigger and hotter than our Sun and is also main sequence star. Probably is also binary star system, with companion white dwarf in close orbit. The surface temperature of the dwarf is about 30,000 K.
Mu Draconis - Its name is Alrakis. This star has combined visual magnitude 4.9. The star is about 85 light years away from the Earth. It consists of two twin components with same visual magnitudes 5.7 and 5.7 and same spectral class and are main sequence stars. It is true binary star system with orbital period of about 670 years. The components are a bit bigger in size and hotter than our Sun. They are separated on the sky about 2 arc seconds.
Nu Draconis - Its name is Kuma. Its combined visual magnitude is 4.1. It is another binary star system composed of identical twins with huge distance between each other and orbital period measured in tens of thousands of years. It is about 100 light years away. Both components have visual magnitude 4.9. They are separated on the sky about 62 arc seconds. Both have white color. They are main sequence stars with mass and size a bit bigger than our Sun. Nu2 is probably closely orbited by its own small mass companion.
Psi1 Draconis - Its name is Dsiban. Even with binoculars can be resolved on its components. They are separated 30 arc seconds on the sky. Their distance from the Earth is about 70 light years. The visual magnitudes of the components are 4.6 and 5.8. Both component are a bit bigger in mass and size than our Sun, and also a bit hotter. In reality the distance between these component is huge and the orbital period is longer than 10,000 years.
41/40 Draconis - Even in binoculars appears like double star. The visual magnitudes of the components are 5.7 and 6.1. Their distance from the Earth is 170 light years. Both components are orange dwarfs. They are separated on the sky about 19 arc seconds. There is another star visible close to this pair at a separation of 220 arc seconds with visual magnitude 7.5.
Deep sky objects
(will be observed only from dark location outside of the city)
NGC 6543 - It is a planetary nebula. Its name is Cat's Eye Nebula. Its visual magnitude is 9.8 and it lies about 3,000 light years away from the Earth. The central star is white dwarf or so-called planetary nebula nucleus. The visual magnitude of the central star is 11.0. The diameter of the nebula is about 0.5 light years. The surface temperature of the central star is around 80,000 K. Its mass is more than one solar mass and its diameter about half the sun diameter. It is estimated that the nebula is only 1,000 years old, when the star slowly ejected its outer gaseous layers. The star ejects its outer layers into space, exposing its hot core. The ejected gas glows because is ionized from the ultraviolet radiation from the hot core and its temperature is about 10,000 K. The glowing gas is called a planetary nebula, because viewed in a telescope looks like planet. In a period of several thousand years, the nebula will disperse into space.
The point on the sky very close to this nebula marks where the north ecliptic pole is.
NGC 5985 / NGC 5982 / NGC 5981 - Three galaxies very close apparently on the sky. They form a group of galaxies called NGC 5985 Group or Draco Group. NGC 5985 is a spiral galaxy we see almost face-on with visual magnitude 11.1. NGC 5982 is an elliptical galaxy and NGC 5981 is spiral galaxy we see edge-on. All of them are about 100 million light years away from the Earth.
NGC 5866 - It is a galaxy. Its name is Spindle Galaxy. We see it edge-on on the sky. This is the Messier object M 102 which coordinates he marked wrongly and could not be found on the sky after. Its visual magnitude on the sky is 10.7. Its diameter is about 60,000 light years and is about 50 million light years away. The galaxy is main member of the NGC 5866 Group of galaxies, small group which includes spiral galaxies NGC 5879 with visual magnitude on the sky 12.4 and NGC 5907 with visual magnitude 11.1 and several other smaller galaxies.