Approximately 1,000 light-years away from Earth lies a cosmic entity called IRAS 23077+6707 (IRAS 23077), which strikingly resembles a gigantic butterfly.
The structure was first spotted in 2016 by Ciprian T. Berghea, an astronomer at the US Naval Observatory, using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). Surprisingly, the structure has remained consistent over the years, puzzling many about what IRAS 23077 actually is.
Recently, two international groups of astronomers used the Submillimeter Array at the Smithsonian Astrophysical Observatory (SAO) in Hawaii for follow-up observations to delve deeper into IRAS 23077.
Their research, documented in a series of papers, reveals that IRAS 23077 is actually a young star encircled by a vast protoplanetary debris disk, the largest observed to date. This finding sheds new light on planet formation and the environments in which it occurs.
The first paper, authored by Berghea, unveils that IRAS 23077 is a young star at the center of what seemed to be an enormous disk conducive to planet formation. In the second paper, spearheaded by CfA postdoc Kristina Monsch, the existence of this protoplanetary disk is confirmed through data from Pan-STARRS and the Submillimeter Array (SMA).
The first paper is accepted for publication, while the second has been published on May 13th in The Astrophysical Journal Letters.
Protoplanetary disks serve as planetary nurseries filled with gas and dust that settle around new stars. Over time, this material organizes into rings that form protoplanets in various orbits, which eventually evolve into rocky planets, gas giants, and icy bodies.
For astronomers, these disks are critical for gauging the size and mass of young stars, as they rotate with distinctive signatures. However, accurate observations of these disks can be challenging due to their orientation relative to Earth.
While some disks are visible “face-on” to Earth observers, others, like IRAS 23077, are seen “edge-on,” causing the disk to obscure light from the star. Yet, the signatures of dust and gas in these disks still glow brightly at millimeter wavelengths, which the SMA captures.
The Pan-STARRS and SWA teams were taken aback by their findings when they observed IRAS 23077 using their combined observatory capabilities.
Kristina Monsch, an SAO astrophysicist and CfA postdoctoral fellow leading the SMA campaign, shared in a recent CfA news release:
“Upon learning about this potential planet-forming disk from Pan-STARRS data, we were eager to observe it with the SMA, which helped us comprehend its physical characteristics. What we discovered was astonishing – signs that this is the largest planet-forming disk yet found. It’s exceptionally rich in dust and gas, the fundamental components of planets.”
“The data from the SMA provide conclusive evidence that we’re observing a disk, and with the estimated distance of the system, it’s orbiting a star likely two to four times the mass of our Sun. The SMA data also allow us to measure the dust and gas in this planetary nursery, which contains enough material to potentially form multiple giant planets, extending over 300 times the distance from the Sun to Jupiter!”
Following Berghea’s discovery of IRAS 23077, he nicknamed it “Dracula’s Chivito,” a nod to “Gomez’s Hamburger,” another protoplanetary disk seen only edge-on.
Given Berghea’s upbringing in Transylvania, near where Vlad the Impaler (the inspiration for Bram Stoker’s story) resided, he chose “Dracula.”
Berghea’s co-author Ana, who grew up in Uruguay, suggested “chivito,” a national dish akin to a hamburger. Co-author Joshua Bennett Lovell, an SAO astrophysicist and SMA Fellow at CfA, remarked:
“The discovery of a structure as extensive and luminous as IRAS 23077 raises significant questions. How many similar objects have we overlooked? Further investigation of IRAS 23077 is essential to explore potential planet-forming pathways in such extreme young settings and how these might relate to the exoplanet populations orbiting stars more massive than our Sun.”
This discovery also motivates astronomers to seek similar entities in our galaxy, potentially offering invaluable insights into planetary systems in their formative stages, which could lead to new understandings of how our Solar System was formed.
The SMA is a collection of telescopes in Hawaii operated jointly by the Smithsonian Astrophysical Observatory (SAO) at the Harvard & Smithsonian Center for Astrophysics (CfA) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan.
