I haven't used my ZenithStar 61 for a few weeks and I didn't have the energy to bring out the AVX and the FLT 91.  So I settled on my smaller and much lighter rig and just spent time imaging Stars.  There are times I wish I had a reflector, maybe it would be possible to separate the Two Stars in this system.

Cor Caroli, Alpha2 Canum Venaticorum (α2 CVn), is the primary component in a binary star system located in the northern constellation Canes Venatici, the Hunting Dogs. With an apparent magnitude that varies from 2.84 to 2.98, it is the constellation’s brightest star. It lies at an approximate distance of 115 light years from Earth. The star serves as a prototype for a class of variable stars known as the Alpha2Canum Venaticorum variables.

The Alpha Canum Venaticorum system consists of two stars separated by 19.6 arcseconds. The stars orbit around a common centre of mass with a period of over 8,000 years. The primary component, Alpha2Canum Venaticorum or Alpha Canum Venaticorum A, is a chemically peculiar white main sequence star of the spectral type A0pSiEuHg. It has a mass 2.97 times that of the Sun and a radius 2.49 times solar. With an effective temperature of 11,600 K, it is 101 times more luminous than the Sun. The star spins at a projected rotational velocity of 18.4 km/s, taking 5.46939 days to complete a rotation. Its estimated age is about 165 million years.

Alpha2 CVn is classified as an Ap/Bp star, a chemically peculiar star with an overabundance of certain metals. The star’s atmosphere shows an overabundance of silicon, mercury and europium, as indicated by the suffix in its spectral type (A0pSiEuHg). Ap/Bp stars typically rotate more slowly than regular A and B-type stars and have stronger magnetic fields. Cor Caroli has a magnetic field 5,000 times stronger than Earth.

The brightness of Alpha2 CVn varies between magnitude 2.84 and 2.98 with a period of 5.47 days. The star serves as the prototype for its own class of variable stars, the Alpha2 Canum Venaticorum variables. Like Cor Caroli, these stars are chemically peculiar main sequence stars with strong magnetic fields and overabundances of some metals. Their brightness typically fluctuates by 0.01 to 0.1 magnitudes with a period of 0.5 to 160 days.The variations in brightness are believed to be caused by an uneven distribution of metals in the stellar atmospheres so that different parts of the stellar surfaces are not evenly bright. The overabundant metals are concentrated into starspots that come in and out of view as the stars rotate, causing the brightness to vary from our point of view. The periods of the variations correspond to the stars’ rotation periods. Bright Alpha2 Canum Venaticorum variables include Alioth in the constellation Ursa Major, Mahasim in Auriga, Alpha Doradus in Dorado, and Mesarthim in Aries.The companion, Alpha1 Canum Venaticorum or Alpha Canum Venaticorum B, is considerably fainter, shining at magnitude 5.60. It is a white main sequence star of the spectral type F2V. It lies a bit farther away, at a distance of 120 light years.Alpha1 CVn has a mass of 1.47 solar masses and a radius of 1.48 solar radii. With a surface temperature of 7,080 K, it shines with 4.931 solar luminosities. It spins with a similar rotational velocity to Alpha2 CVn, 18 km/s.

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