Astronomers have detected for the first time the infrared glow resulting from the collision between two icy giant planets in the ASASSN-21qj star system, located approximately 1,800 light-years from Terra. The star similar to Sol, estimated to be around 300 million years old, showed a significant increase in infrared luminosity from 2018 onwards, with a temperature of around 1,000 K and a duration of around a thousand days. Esse phenomenon partially coincided with a complex and deep optical eclipse that lasted approximately 500 days, beginning 2.5 years after the initial brightness.
The collision involved two exoplanets with masses of several to tens of Earth masses, equivalent to icy giants like Netuno and Urano. The impact generated a cloud of vaporized and superheated debris, forming an expanded structure that emitted detectable radiation. Observações combined ground- and space-based telescopes confirmed the presence of dust and rocks orbiting the star, which explains the variations in starlight.
The event occurred at a distance between 2 and 16 astronomical units from the star, similar to the region between Marte and Urano in Sistema Solar. Astrônomos identified the phenomenon through continuous monitoring, which recorded the infrared glow before the optical obscuration caused by the cloud of debris traveling across the line of sight.
Initial detection details
The star ASASSN-21qj was monitored by transient search programs. The infrared glow appeared unexpectedly and persistently. Pesquisadores noticed that the emission corresponded to a hot and extensive body. An amateur astronomer contributed by noticing unusual variations in posts about the object.
The optical eclipse showed variable depth and wavelength dependence. Isso indicated dispersed particulate matter in an elongated orbit.
Characteristics of the collision remnant
The impact produced a synestia, a donut-shaped structure composed of rock and vaporized gas. Essa rotational formation arose from excess kinetic energy converted into heat. The resulting cloud gradually expanded along the orbit.
The high temperature of the material explains the prolonged infrared emission. Over time, cooling and dispersion of the debris reduced the visibility of the glow.
Comparison with planetary formation processes
Giant collisions occur in young systems during the accretion phase. Primitive No Sistema Solar, a similar event between proto-Earth and a body the size of Marte gave rise to Lua. The case of ASASSN-21qj offers direct observation of similar dynamics in another system.
Studies indicate that such impacts shape the final compositions of terrestrial planets. Detritos may form new bodies or rings around the star.
Implications for future observations
The system continues to be monitored with advanced instruments. Additional Dados help refine post-collision evolution models. The orbital duration suggested by the delay between brightness and eclipse allows us to estimate longer periods.
Ongoing research is looking for spectroscopic signs of chemical composition in the debris. Isso may reveal volatile materials released during impact.
Additional system observations
Infrared monitoring captured the emission peak shortly after the event. The optical eclipse exhibited irregularities consistent with a cloud elongated by orbital shear. The star maintained general stability despite the variations.
Consolidated observational evidence
Combination of optical and infrared photometry confirmed the temporal sequence. The brightening preceded the obscuration by 2.5 years, aligning with orbital travel time. Modelos reproduce the observed luminosity with appropriate mass and distance.
The event highlights the rarity of direct captures of planetary collisions. Observações provide valuable data on final stages of formation of planetary systems.
