BOOTES 
(May, June, July schedule)

     Bootes constellation is spring-summer constellation and it is in best position for evening observing in June when it is at the zenith. We will observe it in May when it is high on the southeastern sky, in June when it is in best position for evening observing and it is at the zenith and in July when it is high on the western sky.   

Double and multiple stars

     Kappa Bootis - It is a double star. The first component has visual magnitude on the sky 4.5 and the second component has visual magnitude on the sky 6.6. The system is about 150 light years away from the Earth. Their separation on the sky is 14 arc seconds. The first component is bigger than our Sun in mass and size and it is subgiant which is ending its main sequence life and soon the fusing of its hydrogen will continue outside of its core. The second component is smaller main sequence star, but still a bit bigger than our Sun. If they are true binary system, their orbital period will be many thousand years.
     Pi Bootis - It is a double star with combined visual magnitude 4.5 and about 300 light years away from the Earth. The first component has visual magnitude on the sky 4.9 and the second component has 5.8. They are separated 6 arc seconds on the sky. The first component is 3 times bigger in mass and diameter than our Sun with surface temperature about 12,000 K. The second is a bit smaller than the first but still bigger and hotter than our Sun. Both stars are main sequence dwarfs. If the stars form true binary system, their orbital period is many thousand years. 
     Zeta Bootis - Its combined visual magnitude on the sky is 3.8. It is a binary star system about 200 light years away from the Earth. The visual magnitudes of the components are 4.5 and 4.6 and their separation is about 1 arc second. Because they are apparently pretty close, in a telescope they will look like one star with shape like egg. The separation is closing in the next several years until 2021. There is optical companion close to this system, with visual magnitude 11.0 and separated about 100 arc seconds. Both components are identical and with mass and diameter a bit bigger than our Sun, and with higher surface temperature. 
     Epsilon Bootis
- Its name is Izar. Its combined visual magnitude is 2.4. The first component has visual magnitude on the sky 2.6 and the second component 4.8. They are about 200 light years away from the Earth. Their separation on the sky is 2.9 arc minutes. The first component is bright giant with mass about 4 solar masses and diameter about 35 solar diameters bit its surface temperature is only 4,500 K giving the star orange color. Only 40 million years old. The second component is main sequence star with mass and diameter bigger than our Sun and also hotter than our Sun. The period of this binary system is many thousand years. This star is one of the most beautiful double stars because of the color contrast between the two components. 
     Xi Bootis
- It is binary star system at a distance of about 20 light years from the Earth. The first component has visual magnitude 4.8 and the second component has visual magnitude 7.0. The orbital period of this system is about 150 years. The components are separated on the sky by about 6 arc seconds. The first component is similar to our Sun - it is main sequence star with 0.9 solar mass and 0.8 solar diameter and  surface temperature 5600 K. But it is only 200 million years old. Our Sun will look like this star on the sky if we place it about 25-30 light years away from the Earth. The second component is even smaller with 0.7 solar mass and 0.6 solar diameter and 4,400 K surface temperature. Same age. In a telescope they should appear yellow and orange.
     Mu Bootis - It is triple star system about 100 light years away from the Earth and its combined visual magnitude on the sky is 4.3. The first component is a star with visual magnitude 4.3 and it is main sequence star or has just started expanding to become subgiant. Its mass and diameter are about twice that of our Sun and its temperature is about 7,000 K. Separated about 110 arc seconds is the second component with visual magnitude 6.5. But that second component is in fact again double star with components separated only 2 arc seconds apparently on the sky. The components are with visual magnitudes 7.1 and 7.6. Their orbital period is about 250 years.

Deep sky objects
(will be observed only from dark location outside of the city)

     M46 - It