NGC 7538

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 the Solar System. It is located in the Cepheus' Arm of the Milky Way and is probably part of the Cassiopeia OB2 complex.[3] It is a region of active star formation including several luminous near-IR and far-IR sources.[3] Stars in NGC 7538 are mainly low-mass pre-main-sequence stars.[4]

NGC 7538

Diffuse nebula
NGC 7538 Herschel 250 μm = Red, Herschel 160 μm = Green, Herschel 70 μm = Blue [1]
Observation data: J2000.0 epoch
Subtype	emission or reflection
Right ascension	23^h 13^m 45.7^s[2]
Declination	+61° 28′ 21″[2]
Distance	9,100[3] ly   (2,800 pc)
Apparent dimensions (V)	9′.00 × 6′.0
Constellation	Cepheus
Notable features	Contains largest known protostar
Designations	Bubble Nebula, Dreyer's Object, Sharpless 158

References

1. Fallscheer; Reid; Di Francesco; Martin; Hill et al. (2013) (2013). "Herschel Reveals Massive Cold Clumps in NGC 7538". Astrophysical Journal. 773 (2): 102. arXiv:1307.0022. Bibcode:2013ApJ...773..102F. doi:10.1088/0004-637x/773/2/102.CS1 maint: multiple names: authors list (link)
2. "NGC 7538". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-10-20.
3. Balog, Z.; Kenyon, S. J.; Lada, E. A.; Barsony, M.; et al. (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.
4. Symposium, International Astronomical Union; Union, International Astronomical (2007-05-28). Triggered Star Formation in a Turbulent Interstellar Medium (IAU S237). Cambridge University Press. p. 458. ISBN 978-0-521-86346-9.

Map showing location of NGC 7538 (Roberto Mura)