We can find these two clouds of interstellar matter in probably the most prominent area of Milky Way in the constellation of Sagittarius. Under dark sky we can spot Lagoon with naked eye as faint patch of light. Trifid requires some some optical aid – like binoculars. Despite their low apparent altitude in the sky both nebulae has ben classified by Charles Messier in his catalogue. Lagoon is M8, and Trifid is M20 in Messier catalogue. At my home location this sky area is moving at low altitude, so imaging it is somehow possible, but requires clear view to southern horizon. I already made an attempt to this area two years ago in Tuscany, but my observing location was not perfect. This summer I collected photons at Tenerife. Weather was not perfect, but I managed to shot few pictures. First one below is Lagoon and Trifid nebulae area imaged in hydrogen alpha band – both nebulae literally float in the hydrogen sea.
Lagoon is classified as an emission nebula and HII region. It is really huge cloud – its real dimensions are about 110×50 light years. Contains several Bok globules – that are dark, collapsing clouds of protostellar material. Some of them have been catalogued by E.E. Barnard (B88, B89 and B296 – see annotated image lower).
Large version https://astrojolo.com/wp-content/uploads/2019/08/2019-08-01-M8-Ha.jpg
Color version here https://astrojolo.com/astrophotography/emission-nebulae/cygnus-wall-and-lagoon-in-color/
Trifid is smaller. Both nebulae are more less at the same distance from Earth, so their apparent size corresponds to their real dimensions. Trifid nebula is a combination of many objects: emission nebula, open star cluster, dark nebula (dark patches are designated Barnard 85) and reflection nebula (not visible here in hydrogen alpha band).
Large version https://astrojolo.com/wp-content/uploads/2019/08/2019-08-01-M8-Ha-crop.jpg
Image technical data: Date: 1-3 August 2019 Location: Tenerife, North Telescope: Samyang 135/2 @ f/2.8 Camera: QHY163M, gain 100 Mount: iOptron SmartEQ Pro Guiding: 30mm guidescope + ASI290MM Exposure: H alpha 50x120 seconds Conditions: transparency good, Moon
