Dark energy camera : researching stars
Cometary globules are dense, compact clouds of gas and dust in space that resemble comets with long, faintly glowing tails. They were first observed in 1976 and are unrelated to comets. These structures typically contain newly formed stars at their cores and are formed by the intense radiation from nearby stars. Cometary globules play a crucial role in the process of stellar birth and evolution within galaxies.
“God’s Hand” refers to a series of spectacular images captured by the Dark Energy Camera (DECam) mounted on the Victor M. Blanco Telescope in Chile. The images reveal CG 4, a cometary globule located within the Milky Way galaxy in the constellation ‘Puppis’, approximately 1,300 light years away. CG 4 features a main dusty head resembling a twisting hand, measuring 1.5 light-years across, with a lengthy tail extending 8 light years. (A light year is the distance light travels in one year, equivalent to approximately 9.46 trillion kilometers).
God’s Hand” seems to extend towards a distant spiral galaxy known as ESO 257-19 (PGC 21338), located over 100 million light-years away.
“Despite its evocative name, “God’s Hand,” there’s nothing supernatural about this celestial structure. The striking image of CG 4 was captured by the DECam (Dark Energy Camera), a sophisticated instrument mounted on the Victor M Blanco Telescope in Chile, positioned at an elevation of 7,200 feet above sea level.
Astronomers serendipitously encountered cometary globules in 1976 while analyzing images from the UK Schmidt Telescope. These formations are challenging to detect due to their faintness, often obscured by stellar dust.
However, the DECam employs a specialized filter capable of capturing the faint red emission from ionized hydrogen, which is found in CG 4’s outer rim and head. While this radiation renders the cometary globule visible, it gradually erodes its head over time. Nevertheless, sufficient material remains within for the formation of new stars, akin to our sun.