NGC 6888 -( Crescent Nebula) is an emission nebula in constellation Cygnus about 5000 light years away from Earth .It was discovered by german astronomer William Herschel in 1792 . The Crescent Nebula it is formed from by the fast stellar wind from the Wolf-Rayet 136 (HD192163) colliding with and energizing the slower moving wind ejected by the star when , it became  a red giant around 250.000 to 400.000 years ago.

Astrophoto equipment: 

telescop-MEADE Triplet Apo 80mm  f/6 Serie 5.000 with  TS universal flatener  for refractors 

mount- Skywatcher HEQ5 Pro guided with PHD GUIDING 2 

photo camera - QHYCCD -cmos QHY 294 Mono Pro with filter wheel QHYCFW3 -7 positions 36mm

guide camera-ZWO ASI 120mm Mono cmos 

guide scop Skywatcher 70 /500mm 

filters- Antlia H alfa 4,5nm.

exposure - 46 x 180 sec .

Location  Roma (Italy) center of the city Bortle 9 light pollution .