Using Enhanced Resolution Imagers and Spectrographs (ERIS) from ESO’s Very Large Telescope (VLT), two teams of astronomers have discovered a protoplanet candidate nestled within a spiral disk surrounding the young star HD 135344B.
This image depicts a spiral disk surrounding Young Star HD 135344b. The observations made using the Enhanced Resolution Imager and Spectrograph (ERIS) identified a candidate planet contributing to the spiral structure in the disk, marked by a white circle. Image credits: ESO/Maio et al.
“While we may never witness the formation of Earth, this is a significant finding,” says Francesco Maio, a doctoral researcher at the University of Florence in Italy and lead author of a paper published in the journal Astronomy and Astrophysics.
Maio and his colleagues identified protoplanet candidates in the surrounding protoplanetary disks of HD 135344b. This F8V star, approximately 11.9 million years old, is situated 135 parsecs (440 light-years) from the Sun, in the Lupus constellation.
The protoplanet is estimated to be twice the size of Jupiter, located at a distance from its host star comparable to that of Neptune from the Sun.
It has been observed maturing at the periphery of the protoplanetary disk as it evolves into a fully-fledged planet.
Similar protoplanets have been detected around other young stars, often exhibiting intricate features such as rings, gaps, and spirals.
Astronomers long suspected that these structures were sculpted by forming planets, clearing away material as they orbit their parent stars.
Until now, however, no one has identified a planet actively shaping these features.
In the discs of HD 135344B, previous observations of swirling spiral arms were made by another team using VLT’s Sphere instrument.
Yet prior observations did not find evidence of any planets forming within this disk.
Utilizing VLT’s ERIS instrument, Maio and his collaborators may have discovered their primary suspect.
They identified a planetary candidate located at the base of one of the spiral arms of the disk, aligning with theoretical predictions about potential planets responsible for such patterns.
“What marks this detection as potentially groundbreaking is our ability to directly observe the signal from the protoplanet, unlike many earlier observations,” he notes.
“This gives us greater confidence in the existence of this planet, as we can see the light it emits.”
This image illustrates possible sub-brown dwarf companions orbiting Young Star V960 Mon. Candidate objects were detected using ESO’s Very Large Telescope (VLT) and the new Enhanced Resolution Imager and Spectrograph (ERIS). The ERIS data is shown in orange, overlaid with prior dusty disk images from VLT’s Sphere instruments (yellow) and ALMA (blue). Image credits: ESO/A. Dasgupta/ALMA/ESO/NAOJ/NRAO/Weber et al.
In a separate study, Anuroop Dasgupta, a doctoral researcher at ESO and Diego Portales University, along with colleagues, observed another young star using the ERIS instrument. V960 is located 1637.7 parsecs (5,342 light-years) away in the Monoceros constellation.
Prior observations using Sphere equipment and large millimeter/sub-millimeter arrays (ALMA) revealed that the material orbiting V960 Mon is shaped into complex spiral arms.
These observations also indicated that large clumps of material around the star undergo gravitational instability, contracting and collapsing—each capable of forming a planet or larger body, thus fragmenting the material.
Dasgupta and his collaborators managed to identify a brown dwarf or sub-brown dwarf companion around V960 Mon.
“Using ERIS, we aimed to discover compact, bright fragments indicative of companions in the disk,” he explains. Their findings are detailed in a paper published in the Astrophysical Journal Letters.
“One potential companion object was found very close to one of the observed spiral arms in the Universe and in ALMA data.”
“This object could represent a planet or a brown dwarf—larger than a planet but lacking sufficient mass to shine like a star.”
“If confirmed, this companion could be the first clear identification of a planet or brown dwarf formed via gravitational instability.”
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F. Maio et al. 2025. Development of Protoplanet candidates embedded using VLT/ERIS on HD135344B disks. A&A 699, L10; doi:10.1051/0004-6361/202554472
Anuroop Dasgupta et al. 2025. VLT/ERIS observations for the V960 series: dust-embedded sub-brown dwarf objects formed by gravitational instability? ApJL 988, L30; doi: 10.3847/2041-8213/ade996
Source: www.sci.news
