Airborne observatory SOFIA sheds light on the evolution of Swan nebula

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is helping astronomers figure out the evolutionary history of the Swan Nebula by capturing its most detailed image. The Swan Nebula came to resemble a swan’s neck only in its recent past after various regions of the nebula experienced a number of star births that changed its shape. The new image also shows the formation of baby star-forming in its centre. A  nebula is a giant cloud of dust and gas in space. Some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova. Other nebulae are regions where new stars are beginning to form. [caption id=“attachment_7882401” align=“alignnone” width=“1280”] A composite image of the Swan Nebula where SOFIA detected the blue areas near the centre that revealed gas as it’s heated by massive stars located at the centre and the green areas are trace dust as it’s warmed both by massive stars and nearby newborn stars. Image credit: NASA[/caption] The SOFIA is an airborne observatory that is a collaboration between NASA and the German Aerospace centre. It comprises of a Boeing 747SP aircraft that is fitted with a telescope. Flying into the stratosphere at 38,000-45,000 feet puts it above 99 percent of Earth’s infrared-blocking atmosphere, allowing astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes.

The Swan Nebula

The swan nebula also is known as the Omega Nebula, Checkmark Nebula and Horseshoe Nebula. It is located around 5,000 light-years away from Earth in the constellation Sagittarius but is one of the most studied nebulae around. Its centre is filled with more than 100 of the galaxy’s most massive young stars and they are many times the size of our Sun. The youngest generations are forming deep in cocoons of dust and gas and the space telescopes find it very hard to peer into the depths. However, SOPHIA’s Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) can pierce through these cocoons.

Massive stars, like the ones in this nebula, release a lot of energy that can change the evolution of entire galaxies. But less than one percent of all stars are this enormous, so astronomers know very little about them. Previous observations of this nebula with space telescopes studied different wavelengths of infrared light and did not reveal the details that SOFIA has detected. The new image has revealed nine protostars. These are areas where the nebula’s clouds are collapsing and creating the first step for the birth of the stars and this step has not been seen before. Scientists have also calculated the age of the nebula’s different regions and found that all different areas formed at different times, but took shape over multiple eras of star formation. “This is the most detailed view of the nebula we have ever had at these wavelengths. It’s the first time we can see some of its youngest, massive stars, and start to truly understand how it evolved into the iconic nebula we see today,” said Jim De Buizer, a senior scientist also at the SOFIA Science Center, in a statement.