NGC 6905 is known as the Blue Flash Nebula. It is a planetary nebula in the constellation of Delphinus located 5.75° northwest of Sualocin (Alpha Delphini).

The nebula has an apparent size of 45 x 35 arcseconds. It is estimated to be 4,240 light-years distant.

The central star in the nebula, which started its life as a Sun-like star and then later shed its outer atmosphere to form the nebula during a red-giant phase, is now a white dwarf with a magnitude of 13.9.

NGC 6905 was discovered by William Herschel in 1784.

North is to the top in the above image.

NGC 6905 Catalogs: NGC 6905, PK 61-9.1 Common Name: Blue Flash Object Type: Planetary Nebula Magnitude: 11.1v Size: 50" x 37" Constellation: Delphinus Image Field Centered At: RA: 20h 22m 23s Dec: +20° 06' 13"