Giant planets hidden in protoplanetary disks? ‘IM Lupi’ verified by simulation | sorae portal site to the universe

【▲ A dust-rich disk surrounding IM Lupi, captured by the European Southern Observatory’s Very Large Telescope (VLT) (the gray circle in the center indicates the location of IM Lupi) (Credit: ESO/H. Avenhaus et al./DARTT-S collaboration)]

In interstellar clouds, which are collections of low-temperature gas and dustA new star is bornThen, around the forming star,A disk made of gas and dustis formed.This disc is“Protoplanetary disk”is called, in whichplanets formingIt is believed that

A young star about 500 light-years away in the southern sky toward the constellation Wolf“IM Lupi”has an interesting protoplanetary disk.

Observations over the last few years show that the disk of IM Lupi is not rotating uniformly, but moves at a different speed than would be expected from a smoothly rotating disk.“kink”It turns out that there are dozens ofAlso, on the top surface of the diskspiral patternis also appearing.

[▲ “IM Lupi” observed with a millimeter wave with a wavelength of 1.25 mm. The white scale bar in the lower right corner indicates a length of 10 AU (Credit: Andrews et al. 2018)]

Previous studies have shown that the vast protoplanetary disk of IM Lupi has an orbit 117 astronomical units* away from the star.huge planetwas suggested to be hidden. This time, Harrison Verios of Monash University in Australia (Harrison Verrios), a research team led byHypothesis verificationThe we.

*Astronomical unit (au): Approximately equal to the average distance between the earth and the sun, 1 astronomical unit = approximately 150 million km

The research team used hydrodynamic modeling to model the disk to understand how the planets affect the IM Lupi protoplanetary disk.100 to 120 AU radius of orbitAssuming the mass of the planet is 2, 3, 5, and 7 times that of Jupiterand as a controlSimulation including a disk without planetsThe we.



The team then modeled the millimeter-wave (wavelength 1.25 mm, indicating warm dust signatures) and near-infrared (wavelength 1.6 μm, indicating polarized light scattered from the disk) emissions from the disk and used the actual observations. for comparison withalso create imagesDid.

As a result, all the characteristics such as the speed change of the disk and the spiral pattern that appeared on the surface wereReproduced by simulation assuming the existence of planetsI was able to do. The research team predicted that a wake caused by planetary motion would appear in the disk’s velocity distribution map.Observations are in good agreement with this predictionHe said he did. Overall,2-3 times the mass of JupiterOne planet withRevolves in an orbit with a radius of about 110 AUIf so, it is said that it was found to be the best match with the observation results.

[▲ Observation (upper) and model (lower) images and velocity maps at 1.25 mm wavelength (Credit: Verrios et al. 2022)]

[▲ Observation (upper) and model (lower) images and velocity maps at 1.25 mm wavelength (Credit: Verrios et al. 2022)]

However, even if signs are found that may indicate the existence of planets in the protoplanetary disk, it is possible that something else, such as gravitational instability, is the cause.IM LupiTo see if a planet is lurking in the disk ofNeeds more researchis. However, in this simulation by the research team,The presence of planets alone could explain all the interesting features of the diskIt is said that it is suggested that

Until now, it was thought that the protoplanetary disk could only be disturbed by planets in a small area around the planet, and that the wide-ranging disturbances seen in MI Lupi’s disk are due to other sources. However, in this simulation, the characteristics appear in a wide range of the disk,Planets may affect a wider area than previously thoughtwas shown.

The images used in this article areThe Astrophysical Journal LettersBased on an article published in the journal,AAS Novato “Evidence for a Hidden Planet in IM Lupi’s DiskIM LupiEvidence for a hidden planet in the disk of2022year8moon1introduced by date.


  • Image Credit:ESO/H. Avenhaus et al./DARTT-S collaborationAndrews et al. 2018Verrios et al. 2022
  • AAS Nova – Evidence for a Hidden Planet in IM Lupi’s Disk
  • The Astrophysical Journal Letters – Kinematic Evidence for an Embedded Planet in the IM Lupi Disk

Sentence/Tetsuro Yoshida

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