About 1,000 light-years from Earth, a huge disk of gas and dust orbits a young star and creates new planets. Not only is it the largest planet that disk astronomers have ever discovered, its behavior is unlike anything seen before.
The disk is about 400 billion kilometers (640 billion miles) across—that’s 40 times the diameter of our solar system. Although it was first identified in 2016, astronomers have now used NASA’s Hubble Space Telescope to capture the first image of this nursery planet in visible light. The new images revealed an unusually turbulent region, with wisps of material extending above and below the disk than expected. Surprisingly, these elongated fibers are concentrated on one side of the disc.
The team published their findings on December 23 in the Astrophysical Journal, including a nickname for the puzzling space object: “Dracula’s Chivito,” a nod to the heritage of the two researchers, one from Transylvania (home of Dracula) and one from Uruguay (home of the chivito, the iconic beef sandwich). Viewed edge-on, the plane-forming disk resembles a sandwich, with a dark central core surrounded by white upper and lower layers of gas and dust.
“The level of detail we see is rare in protoplanetary disk images, and these new Hubble images show that planetary nurseries can be much more active and chaotic than we expected,” said Kristina Monsch, lead study author and postdoctoral researcher at the Center for Astrophysics (CfA), a collaboration between Stanford University and the Smithsonian, in a NASA statement.
“We see this disc almost at the end and its smart top layers and asymmetric features are very impressive,” he added.
A broken heavenly sandwich
All planets form from disks of gas and dust that orbit small stars. Astronomers have long believed that these protoplanetary disks were relatively orderly, peaceful places where planets gradually coalesced over millions of years. Recent research has challenged that assumption, pointing to the great complexity and diversity among these systems. Hubble’s new image of Dracula’s Chivito adds to this growing evidence.
“We were surprised to see that this disk is asymmetric,” co-author Joshua Bennett Lovell, an astronomer at CfA, said in a statement. “Hubble has given us a front-row seat to the chaotic processes that form disks as they form new planets—processes we don’t fully understand but can now study in a new way.”
The fact that Dracula’s Chivito’s elongated filaments are visible only on one side suggests that dynamic processes—such as gas and dust falling into the disc, or other interactions with space outside it—shape the celestial sandwich.
A model of the early solar system
The disk hides a small star (or stars) within it, but researchers believe it could contain a single large, hot star or a binary pair. The disk itself contains 10 to 30 times the mass of Jupiter, meaning there is enough material to form gas giant planets. So, Dracula’s Chivito is basically a scaled-up model of what our solar system looked like 4.6 billion years ago.
“In theory, [Dracula’s Chivito] there could be a large planetary system,” said Monsch.” Although the composition of the planets may vary over such large areas, the basic processes are probably the same. Right now, we have more questions than answers, but these new images are the beginning of understanding how planets form over time and in different places.”
Dracula’s Chivito is therefore a natural laboratory for studying planetary formation, Monsch said. Hubble and other space telescopes, such as NASA’s James Webb, will continue to look at this unique disk to find out what makes up its strange structure.
