Study of Close Stellar Encounters with the Solar System Based on Data from the Gaia EDR3 Catalogue (2104.10487v1)

Abstract: We have studied stellar candidates for close (within 1 pc) encounters with the Solar system. For all of the stars under consideration the kinematic characteristics have been taken from the Gaia EDR3 catalogue. The parameters of the encounters of these stars with the Solar system have been calculated using three methods: (1) the linear one, (2) by integrating the orbits in an axisymmetric potential, and (3) by integrating the orbits in a potential with a spiral density wave. All three methods are shown to yield similar results. We have selected five stars that are good candidates for reaching the boundaries of the Oort cloud and passing through it. Based on the second method, in good agreement with the other two methods, we have obtained the following estimates of the encounter parameters for the star GJ 710: $t_{min}=1.320\pm0.028$ Myr and $d_{min}=0.020\pm0.007$ pc. It is also interesting to note the star Gaia EDR3 510911618569239040 with parameters $t_{min}=-2.863\pm0.046$ Myr and $d_{min}=0.057\pm0.079$ pc.

• The paper refines kinematic parameters of stars passing within 1 parsec using improved Gaia EDR3 astrometry and dynamic modeling.
• It applies linear approximations alongside two Galactic dynamical models to integrate stellar orbits and reduce measurement errors by 30%.
• The findings, including GJ 710's predicted 0.020 pc approach in ~1.32 Myr, highlight potential Oort Cloud perturbations and future comet showers.

Close Stellar Encounters with the Solar System: Analysis Using Gaia EDR3 Data

The paper by Bobylev and Bajkova provides a detailed computational paper of close stellar encounters with our Solar System using Gaia Early Data Release 3 (EDR3) data. The paper refines kinematic parameters of stars likely to pass within 1 parsec of the Solar System and explores their potential influence on the Oort Cloud.

Methodological Framework

The research evaluates encounter parameters using three distinct methods: the linear approximation, and two dynamical models involving Galactic potentials—an axisymmetric potential and a modified potential incorporating a spiral density wave. These models facilitate the integration of stellar orbits within the Galaxy's gravitational framework. The precise trigonometric parallaxes and proper motions from Gaia EDR3 serve as crucial inputs for these calculations, a significant improvement from previous Gaia DR2 data.

Results

The resulting data, comprising the closest stellar encounters to the Solar System, identify notable candidates, specifically highlighting the star GJ 710, which is anticipated to pass within 0.020±0.007 parsecs in approximately 1.320±0.028 Myr. Intriguingly, this supports earlier findings of GJ 710 being a significant perturber of the Oort Cloud. Additional candidates include Gaia EDR3 510911618569239040 with a distance as close as 0.057±0.079 pc.

Numerical Insights

The paper's enhanced kinematic data provide more refined encounter parameters. Especially noteworthy is the substantial reduction in random measurement errors in the encounter parameters, achieved through Gaia EDR3's improved parallax accuracy. For instance, errors in the parameters σ_t and σ_d have decreased by 30%. These improvements underscore the paper's methodological rigor and the enhanced observational capability of the Gaia EDR3 dataset over its predecessor.

Implications and Future Directions

This paper has essential implications for understanding potential perturbations in the Oort Cloud caused by close stellar passages. Such perturbations could potentially lead to comet showers entering the inner Solar System. The computational approach presented opens avenues for future research to refine gravitational modeling methods and integrate additional astrophysical effects, such as galactic tidal influences, on the stellar trajectories.

As next steps in this domain, ongoing advancements in astrometric datasets will further hone the predictive accuracy of stellar encounters. Future data releases from Gaia and other astronomical surveys are expected to provide an even more detailed census of stellar motions, which could reveal more about the structure and history of our Galactic neighborhood.

Emphasizing analytical robustness and numerical precision, the insights from Bobylev and Bajkova's work contribute valuably to the astrophysical community's understanding of stellar dynamics and their far-reaching effects on the Solar System. The detected trends and results may serve as essential benchmarks for theorists and simulators focusing on Galactic dynamics and Solar System evolution in the context of an ever-changing cosmic environment.