Northern Lagoon Nebula
| Polish version is here |
NGC 7538, also often called the Northern Lagoon Nebula, in reference to Messier 8, the Lagoon Nebula, is located in the constellation Cepheus. It is approximately 9,100 light-years from Earth. The largest protostar discovered to date, NGC 7538 S, was detected within it, which is about 300 times larger than our solar system. The nebula is in the Perseus Arm of the Milky Way and is likely part of the Cassiopeia OB2 complex. This is a region of active star formation, including several bright sources of near and far infrared radiation. The stars in the Northern Lagoon are primarily pre-main-sequence objects.
Observations
August 08, 2025, about 10:00 p.m. - Jaworzno, Poland
urban conditions, high level of light pollution
The nebula lies near the open cluster Messier 52 and the Bubble Nebula. I have marked the location where we can find this object on the photograph below.
The Little Dipper Ursa Minor is a less prominent constellation than the Big Dipper Ursa Major, but it is key for navigation because it contains Polaris α Ursae Minoris (the North Star) which is located near the north celestial pole. Stretching out next to Ursa Minor is the Dragon Draco, associated with Ladon (Λάδων), the mythical guardian of the Garden of the Hesperides. This constellation contains about 80 stars visible to the naked eye and can be observed in Poland year-round, though it is best seen in summer. The constellation Cepheus represents the mythical king of Ethiopia, the husband of Cassiopeia and father of Andromeda. Cassiopeia stands out in the night sky with its characteristic "W" (or "M") shape, making it one of the easiest constellations to recognize. Located within the Milky Way, it is rich in open clusters and other interesting objects. To the southeast of Cepheus and Cassiopeia is the Lizard Lacerta, a small constellation that was defined by Johannes Hevelius in the 17th century.
Northern Lagoon is a particularly interesting object. With the help of photographic techniques, we can observe that this cloud of interstellar gas and dust, illuminated by young and newly forming stars, possesses a unique beauty (Photo 2).
In the NGC 7538 region, intense star-forming activity is observed. Data from the Herschel Space Telescope led to the identification of an unusual structure: a dust ring spanning tens of light-years with a mass of about 500 M☉. The mechanism behind its formation remains unexplained. During the same observations, several extensive material condensations were also detected, with diameters ranging from 0.4 to 1.1 parsecs. These cool (below 15K) condensations are considered potential sites for future massive star formation.
Photo 2 parameters:
- Total exposure time: 90 minutes (stack of 360 RAW frames at 15s each)
- DWARF3
- Lens: f=150mm (aperture: 35mm)
- Mount: photographic tripod
Further readings:
- Sandell G., Wright M., A Detailed Study of the Accretion Disk Surrounding the High-Mass Protostar NGC 7538 S, The Astrophysical Journal, 2010, 715 (2), pp. 919-938
- Fallscheer C., Reid M. A., Di Francesco J., Martin P. G., Hill T., Hennemann M., Nguyen-Luong Q., Motte F., Men'shchikov A., André Ph., Ward-Thompson D., Griffin M., Kirk J., Konyves V., Rygl K. L. J., Sadavoy S., Sauvage M., Schneider N., Anderson L. D., Benedettini M., Bernard J.-P., Bontemps S., Ginsburg A., Molinari S., Polychroni D., Rivera-Ingraham A., Roussel H., Testi L., White G., Williams J. P., Wilson C. D., Wong M., Zavagno A., Herschel Reveals Massive Cold Clumps in NGC 7538, Astrophysical Journal, 2013, 773 (2), p. 102
- Kraus S., Balega Y., Elitzur M., Hofmann K.-H., Preibisch Th., Rosen A., Schertl D., Weigelt G., Young E. T., Outflows from the high-mass protostars NGC 7538 IRS1/2 observed with bispectrum speckle interferometry. Signatures of flow precession, Astronomy and Astrophysics, 2006, 405 (2), pp. 521–537
Marek Ples