|Observation data: J2000.0 epoch|
|Type||Emission or Reflection|
|Right ascension||23h 13m 45.7s|
|Declination||+61° 28′ 21″|
|Distance||9,100 ly (2,800 pc)|
|Apparent dimensions (V)||9′.00 × 6′.0|
|Absolute magnitude (V)||—|
|Notable features||Contains largest known protostar|
|Other designations||Bubble Nebula, Dreyer's Object, Sharpless 158|
|See also: Diffuse nebula, Lists of nebulae|
NGC 7538, near the more famous Bubble Nebula, is located in the constellation Cepheus. It is located about 9,100 light-years from Earth. It is home to the biggest yet discovered protostar which is about 300 times the size of our Solar System. It is located in the Perseus Spiral Arm of the Milky Way and is probably part of the Cassiopeia OB2 complex. It is a region of active star formation including several luminous near-IR and far-IR sources.
- "SIMBAD Astronomical Database". Results for NGC 7538. Retrieved 2006-10-20.
- Balog, Z.; Kenyon, S. J.; Lada, E. A.; Barsony, M.; Vinkó, J.; Gáspar', A. (2004). "A Near-Infrared (JHK) Survey of the Vicinity of the H II Region NGC 7538: Evidence for a Young Embedded Cluster". The Astronomical Journal 128 (6): 2942–2953. arXiv:astro-ph/0409115. Bibcode:2004AJ....128.2942B. doi:10.1086/425548.