M8, Lagoon Nebula, Sagittarius, Stellarvue SV78S, MX7C, IDAS, 60min
Info courtesy of SEDs
Info courtesy of SEDs
One of the remarkable features of the Lagoon Nebula is the presence of dark nebulae known as 'globules' (Burnham) which are collapsing protostellar clouds with diameters of about 10,000 AU (Astronomical Units). Some of the more conspicuous globules have been cataloged in Barnhard's catalogue of dark nebulae: Barnard 88 (B 88), the comet-shaped globule extended North-to-South (up-down) in the left half and near top of our image, small B 89 in the region of cluster NGC 6530, and long, narrow black B 296 at the south edge of the nebula (lower edge of the image).
Within the brightest part of the Lagoon Nebula, a remarkable feature can be seen, which according to its shape is called the "Hourglass Nebula". This feature was discovered by John Herschel and occurs in a region where a vivid star formation process appears to take place currently; the bright emission is caused by heavy excitation of very hot, young stars, the illuminator of the hourglass is the hot star Herschel 36 (mag 9.5, spectral class O7). Closely by this feature is the apparently brightest of the stars associated with the Lagoon Nebula, 9 Sagittarii (mag 5.97, spectral class O5), which surely contributes a lot of the high energy radiation which excites the nebula to shine.