I am interested in Double stars and Globular clusters,I wish I could do more to observe / image them better, but am limited by my location and equipment.  I enjoy imaging galaxies (again Limited by my equipment and location) and nebula.   Last weekend at NEAF,  I saw a nice program for spectrometry, but the software is written for the Windows Platform, but that would sure be fun to do to analyze the spectrum of stars.  Anyway, there is so much out there.

Last night I decided to spend some time on Izar at 10 subs in when my ASI 2600MCP decided to quit on me for some reason.  I couldn't get it to start taking images again, but if I restarted my ASIAIR Plus I am sure I could continue, but it was getting late and I didn't feel like starting over.  I brought my equipment back to the garage and called it a night.Izar, Epsilon Boötis (ε Boo), is a contrasting binary star located in the constellation Boötes. It is one of the finest double stars to observe in a telescope. Izar lies at an approximate distance of 203 light years from Earth. It is one of the stars that form the constellation’s recognizable Kite asterism. With an apparent magnitude of 2.37, it is the second brightest star in Boötes, after Arcturus.The Epsilon Boötis star system consists of an orange giant or bright giant of the spectral type K0 II-III and a blue-white main sequence star with the stellar classification A2 V. The stars are separated by 2.852 ± 0.014 seconds of arc which, at a distance of 203 light years, gives a projected separation of 185 astronomical units. The two components orbit each other with a period of at least 1,000 years.The primary star, designated Epsilon Boötis A, has an apparent magnitude of 2.37, while the main sequence companion, Epsilon Boötis B, has a magnitude of 5.12. The star system is visible to the unaided eye, but it appears as a single star. The two components can only be resolved in 3-inch or larger telescopes.Epsilon Boötis A is a relatively young star, with an estimated age of 37.4 million years, but it has already reached a late stage of its life cycle. It has burned through its supply of hydrogen and started fusing helium to carbon in its core. It has expanded to a size about 33 times that of the Sun. With a surface temperature of 4,550 K, it shines with 501 solar luminosities. Its estimated mass is 4.6 times solar.

The companion is at a less advanced phase of its evolutionary cycle. It is a hydrogen-fusing dwarf about twice the size of the Sun, shining with about 27 solar luminosities. It has an estimated surface temperature of 8,700 K. The star is a very fast spinner, with a projected rotational velocity of 123 km/s. By the time it reaches the primary component’s current stage, in a little over a billion years, the larger star will have ejected its outer layers to form a planetary nebula, leaving behind a faint white dwarf. At this point, Epsilon Boötis B will be the brighter of the two stars.Izar is relatively easy to find because it is one of the bright stars that form the kite-shaped pattern of Boötes. The constellation is easy to identify under clear, dark skies because it lies next to the semi-circle of stars of Corona Borealis, and its brightest star, Arcturus, can be found by following the arc of the Big Dipper’s handle. Izar lies northeast (left) of Arcturus. It is the brightest star in the region of the sky between Arcturus and Corona Borealis. It is a popular target for stargazers, mainly for the striking colour contrast between its two components.Izar is located in the constellation Boötes. It marks the Herdsman’s waist cloth.Boötes is one of the largest northern constellations, stretching across an area of 907 square degrees. The first known written mention of its name was found in Homer’s Odyssey, but the constellation itself has been known for much longer.

Other than Izar, Boötes contains several popular telescope targets. These include the multiple star Alkalurops (Mu Boötis), the spiral galaxies NGC 5248 and NGC 5676, the lenticular galaxy NGC 5548, and the globular cluster NGC 5466.The best time of year to observe the stars and deep sky objects in Boötes is during the month of June, when the constellation is particularly prominent in the evening sky.The 10 brightest stars in Boötes are Arcturus (Alpha Boo, mag. -0.05), Izar (Epsilon Boo, mag. 2.37), Muphrid (Eta Boo, mag. 2.68), Seginus (Gamma Boo, mag. 3.03), Delta Boötis (mag. 3.482), Nekkar (Beta Boo, mag. 3.488), Rho Boötis (mag. 3.59), Zeta Boötis (mag. 3.78), Theta Boötis (mag. 4.02), and Upsilon Boötis (mag. 4.023).Izar – Epsilon BoötisSpectral classK0 II-III + A2 VU-B colour index+0.73B-V colour index+0.97Apparent magnitude2.37/5.12Absolute magnitude-1.61Distance203 ± 8 light years (62 ± 3 parsecs)Parallax16.10 ± 0.66 masRadial velocity−16.31 km/sProper motionRA: -50.95 mas/yr Dec.: +21.07 mas/yrMass (ε Boo A)4.6 M☉Luminosity (ε Boo A)501 L☉Radius (ε Boo A)33 R☉Temperature (ε Boo A)4,550 KMetallicity  (ε Boo A)-0.13Age (ε Boo A)37.4 ± 4.2 million yearsRotational velocity (ε Boo A, ε Boo B)10.9 km/s, 123 km/sSurface gravity2.2 cgsConstellationBoötesRight ascension14h 44m 59.21746sDeclination+27° 04′ 27.2099″DesignationsIzar, Epsilon Boötis, ε Boo, 36 Boötis, Pulcherrima, HIP 72105, BD+27° 2417, CCDM J14449+2704AB, ADS 9372 ABEpsilon Boötis AHR 5506, HD 129989, SAO 83500, CCDM J14449+2704A, ADS 9372 A, GC 19856,   GCRV 8567, IRAS 14427+2717, PPM 103553, TYC 2019-1251-1Epsilon Boötis BHR 5505, 129988, CCDM J14449+2704B, ADS 9372 B, GCRV 8568, TYC 2019-1250-1
 @https://www.star-facts.com/izar/