Crescent moon, flying star

 The moon has returned to the evening sky. The hours of darkness for Milky Way viewing will be pushed back later and later as the days progress.

2.8-day crescent moon through the clouds.  AT60ED f/6 telescope.

The clouds were mostly gone by 11 pm.  The measured sky brightness overhead was sqml=21.61. This is a very good value by dark-sky standards.  There is still enough airglow, however, to make the silhouette of Bristol Head easily visible.

Big Dipper and Little Dipper over the northern skyline.  Leica 9mm f/1.7, Sparkle-6 filter.

  The colors of the airglow are imperceptible to the eye, but it's presence is detectable by the backlighting of the surrounding landscape.

Milky Way over the southern flank of Snowshoe Mtn.  Leica 9mm f/1.7, Sparkle-6 filter.

 It is not marked in the above photo, but Nova V462 Lupi is still easily visible with  small telescopes near the southern horizon.  It is past peak brightness, but continues to linger around magnitude 6.

Nova V462 Lupi.  Sigma 56mm f/1.4, Softon filter. 25 June.

 

The constellation Cygnus is home to an historically significant double star: 61 Cygni.  At a combined magnitude of 4.8, it has the largest proper motion (movement with respect to background stars) of any naked-eye star.  This motion was studied by Giuseppe Piazzi (who also discovered the first asteroid, Ceres) in 1804 and earned it the nickname "Piazzi's Flying Star".  The distance to 61 Cygni was measured via parallax in 1838 by Friedrich Bessel, making it the first star system to have its distance measured directly.  The current accepted distance is 11.4 ly.  It (the pair) is the 14th closest star system, and the 21st and 22nd closest stars.  It is the fifth closest naked-eye star system, after Alpha Centauri, Sirius, Epsilon Eridani, and Procyon. 

Deneb, the North America Nebula, and 61 Cygni (circled).  Sigma 56mm f/1.4 + Softon.

The 61-Cygni double is easily resolvable in small telescopes as a pair of golden stars.

61 Cygni.  Celestron C8, E-M5iii, ISO 1600, 2.5 s.