Back when the stars in our universe were initially being formed, they created rotating disks of dust and gas known as protoplanetary disks. These protoplanetary disks slowly congealed into planets — so slowly, in fact, that astronomers speculated all of the protoplanetary disks that once existed have since blown away.
Yet recent images captured by NASA’s James Webb Space Telescope seem to contradict that notion by showing protoplanetary disks in a dwarf galaxy adjacent to our own Milky Way, the Small Magellanic Cloud. Focusing on a cluster known as NGC 346, which contained conditions analogous to those of the early universe, NASA analyzed spectra of light and learned that these stars still have protoplanetary disks.
Although this debunks the previous assumptions about protoplanetary disks, it also confirms earlier images from the mid-2000s from NASA’s Hubble Telescope.
“The Hubble findings were controversial, going against not only empirical evidence in our galaxy but also against the current models,” study leader Guido De Marchi of the European Space Research and Technology Centre in Noordwijk, Netherlands said in a statement. “This was intriguing, but without a way to obtain spectra of those stars, we could not really establish whether we were witnessing genuine accretion and the presence of disks, or just some artificial effects.”
Researchers have two hypotheses as to why these protoplanetary disks persist. The first is that, if these disks form around large gas clouds and form Sun-like stars, it may take a very long time for them to fade away. The second is that NGC 346 is taking more time to dissipate its protoplanetary disks because of radiation pressure being expelled from its stars.
