N44 is a complex nebula filled with glowing hydrogen gas, dark orbits of dust, massive stars and many populations of stars of different ages. One of its most distinctive features, however, is the dark, star-clear hole called a “superboble” visible on this Hubble Space Telescope image in the upper central region.
The hole is about 250 light-years wide, and its presence is still something of a mystery. Stellar winds emitted by massive stars inside the bubble may have driven the gas away, but this does not match measured wind speeds in the bubble. Another possibility, as the nebula is filled with massive stars that would erupt in titanic explosions, is that the expanding shells of ancient supernovae sculpted the cosmic cave.
Astronomers have found a supernova remnant near the superbubble and identified an age difference of about 5 million years between stars within and at the edge of the superbubble, indicating several star-forming events with chain reaction. The deep blue area around 5 o’clock around the superbubble is one of the warmest areas in the nebula and the area with the most intense star formation.
N44 is an emission nebula, meaning that its gas has been activated or ionized by radiation from nearby stars. As the ionized gas begins to cool from its higher energy state to a lower energy state, it emits energy in the form of light, causing the mist to glow. Located in the great Magellanic cloud, the N44 spans about 1,000 light-years and is about 170,000 light-years away from Earth.
A beautiful example of star decoration
Provided by NASA’s Goddard Space Flight Center
Citation: Mysterious “superboble” erodes a fog in new Hubble image (2021, November 3) retrieved November 3, 2021 from https://phys.org/news/2021-11-mysterious-superbubble-hollows-nebula-hubble. html
This document is subject to copyright. Apart from any reasonable trade for the purpose of private investigation or research, no part may be reproduced without written permission. The content is provided for informational purposes only.