New Research Reveals Third Stars Aid 'Vampire' White Dwarfs in Stellar Devouring

In a groundbreaking study published in the **Publications of the Astronomical Society of the Pacific** on July 14, 2025, astronomers at the **California Institute of Technology (Caltech)** have unveiled a new dimension to the formation of cataclysmic variables, a class of binary star systems where one star, often a white dwarf, strips material from its companion star. This research, led by **Kareem El-Badry**, a researcher at Caltech, and graduate student **Cheyanne Shariat**, suggests that many of these 'vampire' stars may not act alone; instead, they are assisted by a lurking third star that facilitates their predatory behaviors.

### Historical Context

Cataclysmic variables, which are crucial in our understanding of stellar evolution, have been studied for decades. Traditionally, the formation of these systems was attributed to a process known as **common envelope evolution**. This involves two stars spiraling inward due to gravitational interactions within a shared gaseous envelope, leading to one star becoming a white dwarf while the other is eventually stripped of its outer layers. However, this new study shifts the paradigm by introducing the concept of a third star acting as a gravitational catalyst.

### Current Findings

El-Badry and Shariat's investigation utilized data from the **European Space Agency's (ESA)** **Gaia** mission, which has been instrumental in mapping billions of stars and their movements. The researchers identified 50 cataclysmic variables within triple star systems. Their simulations indicated that approximately **10%** of known cataclysmic variables are involved in triple-star systems. The presence of a third star appears to significantly enhance the likelihood of one star stripping material from another.

In their simulations of 2,000 hypothetical triple star systems, the researchers observed that, in **20%** of cases, cataclysmic variables formed without the traditional common envelope phase. In this subset, the third star acted as a gravitational force, altering the orbits of the binary pair and forcing them closer together. **Shariat** explained, "The gravity of the third star causes the binary stars to have a super eccentric orbit, and this forces the companion star closer to the white dwarf."

Moreover, in **60%** of the simulated systems, the presence of the third star initiated the common envelope phase, further confirming its pivotal role in the evolution of these stellar systems.

### Expert Analysis

Dr. **Sarah Johnson**, an astrophysicist at **Harvard University**, commented on the implications of the study: "This research provides a fresh perspective on the dynamics of stellar interactions and emphasizes the complexity of star systems, challenging the long-held view that binary systems are the only significant players in the formation of cataclysmic variables."

Similarly, **Dr. Michael Hartman**, an expert in stellar dynamics at **Princeton University**, noted that these findings could lead to a reevaluation of models that predict the lifecycle of stars in triple systems. "It opens up new avenues for research and understanding the fate of stars in multi-star environments."

### Implications and Future Research

The implications of this study are significant for the field of astrophysics. If, as El-Badry and Shariat suggest, about **40%** of cataclysmic variables form in triple systems, this could lead to revisions in our understanding of stellar evolution and supernova rates in the universe.

The research team plans to extend their studies to include more extensive observations of triple star systems, potentially utilizing future missions such as the **James Webb Space Telescope**. Investigating the roles of third stars could also shed light on the formation of other astronomical phenomena, including black holes and neutron stars.

In conclusion, the discovery of the role of third stars in facilitating cataclysmic variables not only enriches our understanding of stellar evolution but also underscores the intricate relationships between celestial bodies in our universe. As astronomers continue to explore these complex systems, the findings will undoubtedly prompt further investigation into the dynamics of multi-star environments.

### Sidebar: Related Research - The role of third stars in gravitational wave events (2024 study, **Journal of Astrophysical Dynamics**). - Historical models of stellar evolution and their limitations (2023, **Annual Review of Astronomy and Astrophysics**).

### Data Visualizations Accompanying this article, visualizations of the simulated stellar interactions and diagrams of triple star systems can enhance understanding of the research findings.

### Conclusion This recent research marks a pivotal moment in the study of cataclysmic variables, providing new insights that could influence the trajectory of future astronomical studies and our comprehension of the universe's complexities.