Bubble nebula is a LRGB composition of 15+15+15+15 frames of 600s each. The totale exposition is 6 hr. It was taken in August 2017 with the GSO and the new ASI1600 CCD.
This large FOV of the Bubble nebula is the sum of 18×1800 Ha frames taken with the FSQ telescope and QHY90A camera in August 2016.
NGC 7635, also known as the Bubble Nebula, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the direction of the open cluster Messier 52. The “bubble” is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in 1787 by William Herschel.The star BD+60°2522 is thought to have a mass of about 44 M☉. (Wikipedia)
The Ha wide field above includes several neighbouring objects:
- M52 is the open cluster in the upper right corner;
- NGC7635 Bubble Nebula;
- NGC7538 It is home to the biggest yet discovered protostar which is about 300 times the size of the Solar System;
- NGC 7510 is an open cluster of stars located around 11,400 light years from the Solar System;
- Sh2-157 or Sharpless 157, also known as the Lobster Claw Nebula, is a bright emission nebula.
The position of these objects is reported in the picture below.