Pesquisadores of Instituto of Astrofísica of Andaluzia have mapped a new newborn star located in the constellation of Sagitário. The celestial body was identified as IRS7 and is part of the formation region known as IRAS 18162-2048. The data collected shows that the object presents a higher evolutionary stage than the main protostar that dominates that sector of space. The team used near-infrared observation instruments to pierce through the thick layer of interstellar dust that obscures the area.
The space sector analyzed is home to the protostellar jet HH 80-81, a phenomenon driven by a central protostar that has a mass 20 times greater than that of Sol. The scientific community has focused efforts on this main source for decades. The new survey recovered information about a second light source originally detected in the 1990s. The intense brightness of the central object overshadowed the presence of IRS7, which remained without in-depth analysis until the application of current light filtering technologies.
Propriedades physics and classification of the new celestial body
The newborn star exhibits characteristics that place it in the age-zero main sequence category. Astronomers classified IRS7 as a B2-B3 type body. Essa definition indicates a hot object, with high luminosity and considerable mass, capable of altering the environment around it. The radiation emitted by the star has already started a photoionization process in adjacent space. The phenomenon creates a compact region of ionized hydrogen that interacts with the remaining materials from the original molecular cloud.
The surveys also point to the existence of a rotating molecular disk associated with the main system in the region. IRS7 draws the attention of researchers because it presents an independent and accelerated evolution trajectory. The celestial body developed its fundamental characteristics more quickly than its massive neighbor. The internal dynamics of the system demonstrate that the star formation process does not occur uniformly, even when objects share the same stellar nursery.
The detection of hydrogen recombination lines with a peculiar spectral profile provided the necessary confirmation about the photoionizing activity. Experts noted that IRS7 has reached a higher degree of stellar maturity, despite having a total mass lower than that of the protostar that feeds the HH 80-81 jet. The difference in the developmental timeline cements the theory that the molecular cloud houses a stellar population made up of multiple generations.
Dinâmica of radiation and impact on the interstellar medium
The interaction between the new star and the surrounding gas reveals specific patterns of energy emission. The behavior of excited molecular hydrogen in the vicinity of IRS7 follows the typical characteristics of an environment dominated by ultraviolet radiation. The radiative transfer models applied by scientists managed to reproduce the ro-vibrational populations observed in the region. Calculations indicate that the temperature of the gas around the star reaches 600 K.
- The light source acts as a B2-B3 star that excites a photo-dissociation region.
- The photon rate of continuous Lyman matches predicted mathematical models for the category.
- The emission pattern rules out the hypothesis of excitation generated by mechanical shocks in the gas.
The study led by IAA-CSIC applied high-resolution techniques to separate the individual contributions of the multiple heat sources present in the cluster. The central protostar remains responsible for driving the high-energy bipolar jet, while IRS7 emits constant ultraviolet feedback. The coexistence of these two distinct mechanisms of interaction with the interstellar medium transforms the region into a natural laboratory for modern astrophysics.
Mapeamento at multiple radio and infrared frequencies
Images captured in the near-infrared range were essential for isolating IRS7 from the main source, which remains obscured at several wavelengths. The team expanded the search and carried out analyzes using radio waves in the X and C bands. The results revealed a compact source that exactly coincides with the star’s spatial position. The recorded emission presents an optically fine free-free radio pattern, characteristic of newly formed ionized regions.
Technological advancement allowed the source to be detected at millimeter wavelengths for the first time. The combination of data from different electromagnetic spectrums confirmed the structural complexity of the area. The ability to observe the same object through infrared, radio and millimeter waves eliminates distortions caused by cosmic dust. The method guarantees precise measurements of the rate of accretion of matter and the surface temperature of the star.
The research published in the journal Astronomy & Astrophysics details the technical parameters that validate the discovery. The lead author of the work, Rubén Fedriani, documented the process of separating the light signals. The applied methodology establishes a new protocol for the investigation of dense stellar clusters located towards the center of Via Láctea. Three-dimensional molecular cloud mapping requires continuous integration of multifrequency data to avoid false positives.
Perspectivas for astronomy with new generation telescopes
IRS7’s detailed identification expands the catalog of priority targets for today’s most advanced observing instruments. State-of-the-art Telescópios, like James Webb Space Telescope and the ALMA observatory, have the technical capability necessary to map hidden structure with unprecedented resolution. The equipment will be able to investigate the accretion and ejection processes of matter in multiple spectral bands simultaneously.
The scientific community considers the IRAS 18162-2048 region a reference model for the study of multigeneration star formation. The discovery reinforces the need to review astronomical sources cataloged in previous decades with the help of new technologies. The brightness of massive objects often hides smaller stars or stars at different evolutionary stages that inhabit the same cosmic neighborhood. Reviewing old data with modern filters has proven to be an effective strategy in astrophysics.
The understanding of how massive stars arise and interact in high-density environments gains a new perspective with the confirmation of the properties of IRS7. The celestial body offers an opportunity for direct observation of the moment of transition between the final protostellar phase and the definitive entry into the main sequence. Continuous monitoring of the region will provide empirical data to calibrate theoretical models on the evolution of high-mass objects in the universe.