“Twinkle, twinkle little star. How I wonder what you are?” is the rhyme we all have known since our childhood. These tiny stars glowing in the sky has made people ponder, as to what must be there beyond it. Space has always been an enigmatic world where one can never quench the thirst to learn more about it. Right from discovering the Sun, the planets and the interstellar system including all those comets and meteors revolving the Sun, scientists yet have great inquisitiveness to know more.
Recently at NASA, the Spitzer space telescope has revealed a stunning structure which resembles a butterfly. Using infrared imaging techniques, four images of this “Space Butterfly” has been merged to unveil this beautiful structure in space. This structure is officially named as Westerhout 40 (W40). It is composed of the nebula which is a mixture of gases and dust in space. “The wings of the butterfly are giant bubbles of hot, interstellar gas blowing from the hottest, most massive stars in this region” NASA explains.
About the Imaging Technique
The Spitzer Space Telescope has captured four images at different wavelengths of infrared light i.e., 3.6, 4.5, 5.8 and 8.0 microns to build this magnificent butterfly picture in space.
Why is the ‘butterfly’ red?
At shorter wavelengths, the stars are brighter and hence they have a blue tint to it. But the younger stars are often surrounded by dust and residual material, resulting in a yellow or a red glow. The reddish hue of the nebula is due to the presence of organic molecules called polycyclic aromatic hydrocarbons (PAHs) comprising of carbon and hydrogen that are excited by interstellar radiations. These molecules at a wavelength near 8.0 microns become luminescent.
Physics behind Formation of Stars
W40 is a nursery to newborn stars. This structure illustrates the process of formation of stars in space. However, this results in obliterating the clouds from where they arise. During this process, inside this giant nebula, the force of gravity acts in it magnetizing the material together to form huge, dense clumps. Once these clumps reach their critical densities, the stars start forming and emerging from their cores. Accompanied by several radiations and winds coming from the most dynamic stars in those clouds causes stars to explode. Sometimes, they also result in the formation of bubbles like those in W40. Dispersion of gases and dust could lead to breaking of the dense clumps that reduces or pauses the process of formation of stars.
In W40 the hottest and the most massive amongst these stars, W40 IRS 1a, is positioned in the center of a cluster of stars. These stars give rise to the wings. W40 is situated about 1400 light years from the sun, equivalent to that of the well-known Orion nebula.