Image 1 Caption: A image of double star Albireo AB (β CYG AB, V_mag 3.1,5.1, angular separation 35'') in the Northern Hemisphere summer sky constellation Cygnus (Swan) taken 2023 Jul07.

You need to click on Image 1 and click on Albireo to get an enlarged view.

To locate Cygnus on an all-sky sky map, see Sky map files sky_map_all_sky.html

Features:

1. It is NOT known if Albireo A and Albireo B are gravitationally bound, and therefore form a binary star system or if they are just an optical double star (see Wikipedia: Albireo: Properties).

2. Albireo A is itself a binary star system (which is unresolved in Image 1 by a large margin) consisting of Albireo Aa and Albireo Ac. There is an unconfirmed 3rd star called Albireo Ab. If it exists and is gravitationally bound to Albireo Aa and Albireo Ac, then the 3 stars form a triple star system.

   

3. Image 2 Caption: A sky map showing constellation Cygnus (Swan) and Lyra (Lyre), 2 of the IAU 88 constellations.

   Selected astronomical object named and unnamed in the sky map: Albireo AB (β CYG AB, V_mag 3.1,5.1, angular separation 35'') Cepheus (King Cepheus), Cygnus (Swan), Deneb (α CYG), Draco (Dragon), Hercules (Heracles), Lyra (Lyre), Messier objects (M27 (Dumbbell Nebula), M39, M56, M57 (Ring Nebula)), Milky Way (shown by the smudgy blue band), Summer Triangle (asterism formed by Altair, Deneb, Vega), Vega (α LYR, V_mag 0.03), Vulpecula (Fox).

Images:

1. Credit/Permission: © Robert Royer III, 2023 / Personal permission.
   Image link: Itself.
2. Credit/Permission: © Torsten Bronger (User:Bronger), 2010 (uploaded to Wikimedia Commons by User:Kxx, 2010) / CC BY-SA 3.0.
   Image link: Wikimedia Commons: File:Cygnus constellation map.svg.