SUNSET: 
0
Photographer:
Daniel Stern
Location of Photo:
Rio Hurtado, Chile
Date/Time of photo:
July and August 2023
Equipment:
CDK 16 Moravian C4 Camera
Description:
This is a close-in view of the emission nebula NGC 6357. It’s more commonly known as the Lobster Nebula or the War and Peace Nebula. The image shows the central part of NGC 6357, revealing one of the most prominent sites of massive-star formation in our Milky Way neighborhood, and specifically Pismis 24. This picture was taken with a telescope having a focal length of almost 3 meters (in this case, a longer focal length would be better) to highlight the blue area in the middle of the picture. If you look closely in the blue area there is an inverted finger-like structure pointing to a group of stars. A larger star to the right and two side-by-side stars to the left. The larger star to the right is Pismis 24-1. When first studied it was thought to be a single star with a mass of at least 300 times the mass of the Sun. It was bigger than was thought theoretically possible. It was subsequently discovered to be a binary and then a triple, as new science developed and therefore in the expected size range of an O-type star.. The three bright stars in-line in the left central part of the image are protostars. A protostar is a very young star that is still gathering mass from its parent molecular cloud, an unseen halo of dense gas and dust surrounding the stars. A visual indication of the cloud was revealed by the Dark Energy Camera on the Víctor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory in Chile.
