Vast Stellar Nursery of Lagoon Nebula
Hubble Space Telescope celebrated its 28th anniversary in space by comparing Lagoon Nebula in the visible and infrared light.
The Lagoon Nebula, also known as M8 or RCW146, is a colossal interstellar cloud in the constellation Sagittarius. This emission nebula was discovered before 1654 by an Italian astronomer, Giovanni Hodiema. There are only two nebulae that can be seen from naked eye of a human and it is one of them.
You can observe it in the dark and clear skies of the areas which fall in the range of mid-northern latitudes. The fact that it is 55 light years wide and 20 light years tall clearly indicates the magnitude of this nebula. A lot of people might wonder why this is visible to the human eye as it is 4000 light years away from Earth. The reason for this is its huge size. According to an estimate, it is three times larger than the full Moon. Hubble can capture only 4 light years across this massive structure of nature’s artistry.
Hubble Space Telescope has given numerous gifts to the world of astronomy since its launch. It made extraordinary revelations about our universe and gave scientists a lot to play with. It was launched on 24th April 1990 collectively by NASA and ESA and has exceeded all expectations by spending 28 years in space. It’s not done yet and promises to provide several more out-of-this-world details in the coming years.
The space agencies associated with this telescope release images, taken by it annually, to celebrate the anniversary of this revolutionary equipment. The images selected this year shows a spectacular view of Lagoon Nebula. One of the images was taken in optical light while the second image was taken in an infrared environment.
Lagoon Nebula follows the general pattern of stellar nurseries as it has many large stars at incredibly hot temperatures. The UV rays are responsible for their bright shine as they ionize the gas particles present around these stars. The irregular shapes are also caused due to this process. The central star in the image is known as Herschel 36. It is surrounded by dark clouds that are carved due to the radiations emitting from it. As particles of a gas are removed, regions having varying densities are formed.
This has led to two interstellar twisters. They are rope-like structures and each one of them is about 0.5 light years in length. According to scientists, these structures are wrapped inside their funnel-like shapes due to the difference of temperature between the interior and exterior parts of the clouds. It is also believed that these clouds will form new stars of their own in the future when these clouds will collapse under their own weight.
Looking at the images taken by Hubble, you might not understand the reason behind its name. The reason for this is that those images show incredible scenes observed at the center of this nebula. The logic behind it being called Lagoon becomes clear when you observe it in a broader spectrum as lagoon-shaped dust lane crosses this nebula.
The visible light image takes you to a world of fantasy where colorful landscape including mountains of gas, cavities, and ridges awaits you. As discussed above, ultraviolet radiations alongside rapid stellar winds are the reasons behind such an atmosphere. The infrared image is much more helpful in determining that it is a stellar nursery. Herschel 36, in the center, is surrounded by countless stars. It is 32 times bigger and 200,000 times brighter than our Sun. The surface temperature of this star is estimated to be 40,000 Kelvin. As it is only 1 million years old, which is pretty young by a star’s standards, it is regarded as extremely active.
An interesting discovery that came forward about Lagoon Nebula is that the radiations and stellar winds are pushing dust away into the surroundings and it suppresses star formation in those parts of space. Having said that, the cocoon at the dark edges is resistant to erosion and provide a feasible environment for the formation of stars. Scientists have realized that both visible and infrared lights are necessary for examining this nebula. Infrared helps to examine the stars hidden beneath the clouds of gas and dust whereas optical vision allows studying the gas in detail.