Astronomers spot star WOH G64, 1540 times bigger than the Sun, turning into a yellow hypergiant in the Large Cloud

Astronomers have recorded an unprecedented transformation in the star WOH G64, located at Grande Nuvem of Magalhães, approximately 163 thousand light years from Terra. Essa star, with an initial radius approximately 1,540 times that of Sol and a mass around 28 times greater, went from a red supergiant to a yellow hypergiant in a short period. The changes began to be noticed in 2011, with a gradual dimming, followed by an increase in brightness between 2013 and 2014.

The star’s surface temperature rose more than a thousand degrees Celsius, changing its color from red to yellow. Essa rapid evolution challenges traditional models of massive stars, which generally consume nuclear fuel at accelerated rates. At only about 5 million years old, WOH G64 exemplifies how giant celestial bodies live short lives on cosmic scales.

Researchers identified that the star is part of a binary system, with a companion that can influence its evolution. Essa binary interaction suggests scenarios such as mass transfer or outer envelope ejection, explaining the observed transition. The discovery offers valuable insights into the final stages of massive stars, potentially leading to a supernova or direct collapse into a black hole.

Observed changes in stellar structure

The decrease in the radius of WOH G64, from about 1,540 to approximately 800 times that of Sol, occurred smoothly, with no violent events detected. Essa contraction raised the surface temperature, eliminating spectral features typical of red supergiants, such as titanium oxide bands.

Spectroscopic observations confirmed the absence of these markers, indicating a yellow hypergiant phase. Essa step is rare, with only dozens of known examples in the universe, due to its brevity in astronomical terms.

Possible causes of the transition

Binary interactions emerge as a key factor in the metamorphosis of WOH G64. The main star may have engulfed its companion during expansion as a red supergiant, forming a common envelope of gas. Partial ejection of this envelope would reveal the binary system, with the main one appearing hotter and yellower.

Processes intrinsic to the star, such as prolonged eruptive episodes, are also considered. Esses events could last for decades, leading to the loss of outer layers and a return to a quiescent yellow state. Ambas the hypotheses highlight the rarity of witnessing such changes in real time.

Intense stellar winds, common in bright red supergiants, facilitate the removal of external material. In the case of WOH G64, powerful flows may have driven the transition, raising the temperature and changing the stellar classification.

Impact on understanding stellar evolutions

Massive stars like WOH G64 consume hydrogen and helium quickly, leading to unstable phases in the final stages. The observed transformation suggests that not all red supergiants follow the same path, with some evolving into yellow hypergiants before collapsing.

This discovery reinforces the need to monitor binary systems in satellite galaxies of Via Láctea. Grande Nuvem of Magalhães, with its relative proximity, allows for detailed observations that would not be possible at greater distances.

Theoretical models predict that stars between 23 and 30 solar masses face uncertain fates after the red phase. WOH G64, with its estimated mass, serves as a case study to refine these predictions.

The presence of a dense dust ring around the star, observed since the 1970s, may be related to the ejection of material during the transition. Esse dust torus offers clues about stellar mass loss over time.

Details about the binary system

WOH G64’s companion appears as a hot star, possibly influencing the evolution of the main star through mass transfer. Essa binary dynamics complicates evolutionary scenarios, as interactions can accelerate or alter stellar phases.

Recent observations indicate that other extreme red supergiants may also be binary. Entender Whether extreme properties arise from intrinsic factors or interactions is essential to predicting supernovae and resulting black holes.

In merger scenarios, stars could collide, releasing immense energy. Alternativamente, light interactions would lead to the collapse of the main core, potentially without a visible explosion.

Future perspectives for WOH G64

The evolution of WOH G64 remains uncertain, with supernova possibilities on short astronomical scales, ranging from centuries to millennia. Continuous Monitoramento with telescopes like the Very Large Telescope can capture additional steps.

This star offers a rare window into processes that shape massive stellar populations. Compreender its trajectory helps interpret distant cosmic events, such as supernova explosions observed in other galaxies.

Contributions to astronomy

The WOH G64 transformation highlights the importance of long-term surveys in regions such as Grande Nuvem to Magalhães. Dados photometric and spectroscopic measurements accumulated over years revealed changes that would be imperceptible in isolated observations. Essa integrated approach allows mapping stellar evolutions with unprecedented precision.

Searches of similar stars reveal patterns in transition phases. Hipergigantes yellow colors, being transient, require timely detection for detailed study. The WOH G64 exemplifies how rare events can be captured with current technology, enriching evolutionary models.

Observational data analysis

Time series photometry showed variations in the star’s brightness from 2011 onwards, with recovery in 2013-2014. Subsequent Espectroscopia confirmed shifts in absorption lines, consistent with increasing temperature. Esses data, collected by international teams, validates the classification as a yellow hypergiant.

The reduced radius implies significant loss of mass, possibly ejected as stellar wind or during binary interaction. Cálculos indicate that the outer envelope has been partially removed, exposing hotter inner layers.

The star’s luminosity, about 282,000 times that of Sol, remained high despite the changes. Essa stability suggests that the core continues to fuse heavy elements, approaching collapse.

Instruments like GRAVITY on Very Large Telescope Interferometer captured detailed images of the system in 2024, confirming its binary nature. Essas high-resolution observations reveal separations and orbits, essential for modeling interactions.

Implications for supernova studies

Stars like WOH G64 are potential progenitors of type II supernovae, characterized by core collapse. The yellow hypergiant phase may precede such events, offering observable precursor signs. Monitorar variations in brightness and temperature could predict explosions in other massive stars.

In nearby galaxies such as the LMC, resulting supernovae would be detectable with current telescopes. Elas would release heavy elements, enriching the interstellar medium and influencing the formation of new stars.

• Supernovae produce black holes or neutron stars, depending on the remaining mass.
• Binary interactions can alter residues, leading to mergers or ejections.
• WOH G64 data refines computational simulations of stellar evolutions.

Stellar evolution in binary contexts

Binary systems represent a significant fraction of massive stars, with interactions shaping destinies. In WOH G64, the companion may have removed the envelope of the parent, accelerating the transition to yellow. Esse mechanism explains why some red supergiants avoid direct explosions.

Comparisons with other known binaries, such as hypergiants in our galaxy, reveal similarities in common envelopes. The gas ejection creates structures like dust rings, observed around WOH G64.

The symbiotic phase, where stars interact mutually, adds complexity. Nesse state, mass transfer sustains luminosity, prolonging stellar lifetimes.

Evolutionary models incorporate these factors, predicting supernova rates in stellar populations. The WOH G64 serves as a benchmark to validate theories.

Recent Discoveries in Massive Stars

Advances in interferometry have made it possible to resolve binary components at galactic distances. Para to WOH G64, this confirmed the presence of a hot companion star, altering previous interpretations of its solitary evolution.

Studies on other extreme red supergiants suggest that binarity is common among them. Propriedades how inflated sizes can result from interactions, not just internal pulses.

The smooth transformation, without violent eruptions, contrasts with expectations of abrupt changes in massive stars. Isso indicates gradual processes in stable systems.

Continuous monitoring and predictions

Science teams plan additional observations to track variations in WOH G64. Telescópios spacecraft, like James Webb, can analyze the chemical composition of the dust ring, revealing the history of ejections.

Predictions indicate that, in astronomical terms, core collapse could occur soon, although on human scales this would mean thousands of years. Qualquer precursor signal would be invaluable to science.

The discovery emphasizes the dynamics of the universe, where rare events offer lessons about cosmic cycles.