Hello friends of binocular astronomy,

below find please my favourite bright and close double stars, I regularly visit with my 10.5x70 binocular.

Theta1-2 Serpens Caput (Alya), Mayer 60, Struve 2413: very bright double 4.59/4.95 magnitudes, 23" separation, 104° position angle. The both bright components are white, A5/A5. Binoculars show also a third faint (8mag) component, wide separated at 414", at the position angle 56°. Navigate the direction of the open clusters NGC6633 - IC4756 to get there.

Beta Cygni (Albiero), Mayer 62, Struve 37: bright primary star (3.19mag) with fainter (4.68mag) companion separated by 35.3" at 54°. The spectral classes K2 and B9 make an amazing colour contrast.

61Cygni (Bessel's parallax star), Mayer 70, Struve 2758: two bright (6.2/6.0mag) orange (K5/K7) stars separated by 30.3" at 150°. This is one of the easy-to-see fast orbiting doubles with the period of 653.34 years. Move to the south-eastern wing of Cygnus, the double star is west of Sigma-Tau Cygni.

16Cygni, Struve 46 is a multiple system including a red dwarf, and a planet. The planet orbits the fainter component (6.20mag) at 778.5 days. A small binocular shows two bright stars (5.96/6.20mag) separated by 39.3" at 134°. Both look white (G2/G5).
This double star is close to the Blinking Planetary Nebula NGC6826, which can be also seen as a star-like object with binoculars. West of 16Cygni is a streak of 3 stars, including 13(Theta)Cygni. To the east of Theta Cygni is the red (spectral class S7) variable 6.1-14.2mag, with the period of 426.44 days. 2° south of 16Cygni is RTCygni, a red Mira-variable (spectral class M7) 6.0-13.1mag, with the period of 190 days. Both can be seen with binoculars, whenever close to their maxima of brightness.

Epsilon1 and Epsilon2 Lyrae, Mayer 57 and Mayer 58, Struve 37, is the famous wide double of the two easy-with-a-telescope close double stars in Lyra. This object deserves the nickname: Double-Double.

Zeta Lyrae, Struve 38, is another nice bright (4.34/5.62mag) double star in Lyra, separated at 43.6" with 150°.

Nu1-2 Draconis (Kuma), Struve 35, is a bright (4.88/4.87mag) double star, separated by 63", at the "head of Draco".

Psi1 Draconis (Dsiban), Struve 2241 is a "fast orbiting" (1250 years) bright (4.6/5.6mag) double star, separated with 29.6". Start at the "head of Draco" and follow the bright stars of Draco to get there.

Kappa Herculi, Struve 2010, is a bright (5.00/6.25mag) double star with a yellow/orange colour contrast (G8/K2), separated at 28", at the position angle of 10°.

36-37 Herculi, Mayer 41, Struve 2074, is a wide (69.1") and bright (5.76/6.92mag) double star at the position angle of 230°

The names Mayer and Struve refer to the historical catalogues of the binary stars, the less known Christian Mayer has been contemporary of Charles Messier.

Visual resolution of the binary stars with binoculars depends both on their separation and brightness. The separation is given in arc seconds ("), and the position angle of the secondary (fainter) component to the brighter (primary) component is measured anti-clockwise in angular degrees (°). The separation and the angular position of the double stars change with time.

Very good binoculars with the magnification of 10x, and mounted on a tripod, allow to resolve the double stars with the separation down to 23", showing a "touching" pair of pinpoints. Most hand-held binoculars with magnification of 10x can easily resolve the double stars with the separation of slightly below 30".

Best

JG