This image of a strange object in space that resembles a butterfly actually shows a giant disk of swirling gas and dust out of which planets will eventually be born.
It's likely the largest planet-forming disk ever seen, and is located about 1,000 lightyears from Earth.
Officially known as IRAS 23077+6707 (IRAS 23077, for short), the cosmic butterfly is a prime example of a protoplanetary disk, or planet-forming disk.
Planet-forming disks explained
When a star is born, much of the material that went into forming that star remains, resulting in a disk of gas and dust in orbit around it.
Over time, gravity pulls clumps of this material together, forming small pebbles and rocks that accumulate more material, growing and growing to eventually form a system of planets orbiting that star.
The same is true of our own Solar System: the planets, moons and asteroids are made up of material left over from the formation of our host star, the Sun.
Protoplanetary disks are rich in dust and gas and rotate with a specific signature that astronomers can use to calculate their sizes, but also the mass of the host star.
Like galaxies, some disks are edge-on, meaning we see them angled away from us, while some are face-on.
IRAS 23077 is edge-on, which means its dusty disk obscures the light from its host star.
Yet the disks themselves can still shine brightly at certain wavelengths, as is the case in this image captured by the Submillimeter Array (SMA), which is an array of ground-based telescopes in Hawaii.
How the IRAS 23077 discovery was made
IRAS 23077 was initially discovered in 2016 by Ciprian T. Berghea from the US Naval Observatory using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS).
But it remained uncharacterised until the release of two more recent papers.
One paper, led by Berghea and published in The Astrophysical Journal Letters, shows IRAS 23077 is a young star in the middle of what appear to be a huge planet-forming disk.
A second paper, also in The Astrophysical Journal Letters, confirms that it is in fact a planet-forming disk, using the Submillimeter Array.
"After finding out about this possible planet-forming disk from Pan-STARRS data, we were keen to observe it with the SMA, which allowed us to understand its physical nature," says Kristina Monsch, an SAO astrophysicist and a postdoctoral fellow at the CfA, who led the SMA campaign.
"What we found was incredible – evidence that this was the largest planet-forming disk ever discovered. It is extremely rich in dust and gas, which we know are the building blocks of planets.
"The data from the SMA offer us the smoking–gun evidence that this is a disk, and coupled with the estimate of the system’s distance, that it is rotating around a star likely two to four times more massive than our own Sun," says Monsch.
"From the SMA data we can also weigh the dust and gas in this planetary nursery, which we found has enough material to form many giant planets – and out to distances over 300 times further out than the distance between the Sun and Jupiter."
Science takeaways
"The discovery of a structure as extended and bright as IRAS 23077 poses some important questions," says co-author Joshua Bennett Lovell, an SAO astrophysicist and an SMA Fellow at CfA.
"Just how many more of these objects have we missed? Further study of IRAS 23077 is warranted to investigate the possible routes to form planets in these extreme young environments, and how these might compare to exoplanet populations observed around distant stars more massive than our Sun."
The SMA is an array of telescopes in Hawaii jointly operated by the Smithsonian Astrophysical Observatory (SAO) at the Center for Astrophysics | Harvard & Smithsonian (CfA) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan. It detects light at millimeter wavelengths, a type of radio wave.
