Farmakopoulos Antonis
NGC 7635 or Bubble Nebula, Sharpless 162 is a emission nebula in the constellation Cassiopeia. The "bubble" is created by the stellar wind from a massive hot magnitude young central star SAO 20575. The distance of the Earth is 7100 light year and has a diameter of 6 light-years.
For more technical details look here http://astrofarma.gr/index.php/en/bubble