Planets form in protoplanetary disks from the gas and dust left over from star formation. The idea that this process is completely open is misleading. In fact, scientists have managed to find too many protoplanetary disks and even fewer to study them. They now have a wonderful object to examine in detail: the giant “Dracula’s Chivito” or IRAS 23077+6707.

The study of protoplanetary disks is complicated by the fact that their complex three-dimensional structure can only be viewed from a single viewpoint. If such a system is returned to us “upside down”, astronomers examine the plane of the disk: for example, they look for voids – signs that planets are forming. If the system is rotated sideways, scientists have the opportunity to study the vertical structure of the disk. At the same time, the dense “plane” hides the “dazzling” light of the star, allowing more detail to be seen.

Another difficulty in studying protoplanetary disks is the need to observe at different intervals. Thus, the millimeter range allows you to detect reflected radiation from large particles, the size of which is calculated in millimeters and centimeters. The optical and near-infrared range helps see the smallest dust particles in micron size. They “float” in giant hemispheres on either side of the disk.

In an article published in the Journal Astrophysics Journal Lettersscientists have presented the first results of such combined observations of the protoplanetary disk IRAS 23077+6707.

The object, detected in 2016, is located on the side and looks like a butterfly in the photos. However, the authors of the first detailed description suggested calling it “Dracula’s Chivito” in honor of the national Uruguayan sandwich stuffed with beef steak.

A dense layer of gas and dust hides the young star, which is about twice the diameter of the Sun and 2.5 times more massive. The system, as before, is surrounded by remnants of the gas shell – these are the same “butterfly wings”. Estimates put the disk’s mass at about 0.2 solar masses, including 20 percent larger particles.

What matters is the size of the IRAS 23077+6707 disk. It lay in the sky for about 14 seconds. The previous record holder is IRAS 18059-3211 or Gomez Hamburger, which extends to 12 arcseconds. The larger the size, the easier it is to observe.

The actual size of the disk cannot yet be accurately estimated. Scientists are sure that the system is in the region of stars in the constellation Cepheus. The region covers a large area between 580 and 2.6 thousand light years away from us. At this distance, the actual diameter of the Chivito Dracula disk is thousands of astronomical units, that is, hundreds of billions of kilometers. But for now, what really matters is how big it looks to us.

An interesting feature of the disk IRAS 23077+6707 is the difference between its “butterfly wings”: one half is six times brighter than the other. Considering that the disk is facing us from its edge (approximately 80 degrees of inclination), this difference raises questions. In addition, scientists noticed similar asymmetries even in perfectly “lying” disks.

According to the assumptions of astronomers, there are various physical processes that could create such a discrepancy in the brightness of the “wings”. For starters, it may be a “legacy” of the early stages of star formation. On the other hand, there is more and more confirmation that the “culprits” may be planets. “Dracula’s Chivito” is just like computer models of this type of “intervention”.

A fairly powerful planet can not only “vacuum” the strip in the protoplanetary disk, separating the inner from the outer, but also distort them. As simulations show, a huge shadow can appear even if parts of the disk deviate from each other by less than one degree. This is what theoretically causes a wing to become faint. In a study published in 2023, scientists calculated that the number of discs detected and turned towards us from their edges was very different from the estimates. Since even a huge disk like “Dracula’s Chivito” has long escaped the attention of astronomers, we are likely to find many more such objects. As for IRAS 23077+6707 itself, more definitive studies of its structure are likely to emerge soon.