Gliese 710 will pass the Sun even closer

Abstract

Context.First results based on Gaia data show that the well-known star Gliese 710 will be the closest flyby star in the next several Myrs and its minimum distance from the Sun will be almost five times smaller than that suggested by pre-Gaia solution.Aims. The aim of this work is to investigate the proximity parameters and the influence of the close approach of Gliese 710 on the basis of Gaia DR1. Furthermore, we compare new results with previous works based on HIP2 and Tycho 2 catalogues to demonstrate how Gaia improves the accuracy of determination of such phenomena. Methods. Using a numerical integration in an axisymmetric Galactic model, we determine new parameters of the close encounter for Gliese 710. Adding ten thousand clones drawn with the use of a covariance matrix, we estimate the most probable position and velocity of this star at the minimum distance from the Sun. Results. Our calculations show that Gliese 710 will pass 13 365 AU from the Sun in 1.35 Myr from now. At this proximity it will have the brightness of −2.7 mag and a total proper motion of 52.28 arcsec per year. After the passage of Gliese 710 we will observe a large flux of new long-period comets. Thanks to the Gaia mission, the uncertainties of the minimum distance and time of the close approach are several times smaller than suggested by previous works based on data from earlier observations.

The completeness-corrected rate of stellar encounters with the Sun from the first Gaia data release

“…This makes Gl 710 once again the closest known stellar encounter 3 . Berski & Dybczyński (2016) found a very similar value using the same data and a similar method. Although this close approach will take Gl 710 well within the Oort cloud -and its relative velocity at encounter is low (14 km s −1 ) -its low mass Fig.…”

“…This is analysed by Berski & Dybczyński (2016). The second closest encounter is Tyc 4744-1394-1 at d med ph = 0.87 pc, two million years ago.…”

“…Such studies came into their own after 1997 with the publication of the Hipparcos catalogue, which lists the positions, proper motions, and parallaxes of some 120 000 stars. The various studies performed before and since Hipparcos have identified tens of stars which have -or which will -come within 2 pc of the Sun (Matthews 1994;Mülläri & Orlov 1996;García-Sánchez et al 1999, 2001Dybczyński 2006;Bobylev 2010a,b;Jiménez-Torres et al 2011;Bailer-Jones 2015a;Dybczyński & Berski 2015;Mamajek et al 2015;Berski & Dybczyński 2016). One of these articles, Bailer-Jones (2015a, hereafter Paper I), is the precursor to the present work, and was based on the Hipparcos-2 catalogue Full Table 3 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A8 (van Leeuwen 2007) combined with various radial velocity catalogues.…”

First stars that could significantly perturb comet motion are finally found.

“…All numerical integrations were performed in the galactocentric frame. We obtained the position and velocity of the Sun and each star in that frame by using formulas and parameters gathered in Berski & Dybczyński (2016).…”

Search for close stellar encounters with the solar system from data on nearby dwarfs

“…For example, Bobylev [9] used data from the revised HIPPARCOS catalog to determine this star's minimum distance to be d m = 0.31 ± 0.17 pc at the epoch t m = 1447 ± 60 thousand years in the future. Finally, a completely new estimate was made by Berski and Dybczyński [11] using parallaxes and proper motions measured by GAIA [12], yielding d m = 0.065±0.030 pc and t m = 1350 ± 50 thousand years. Thus, the star GJ 710 currently holds the record for the closest encounter.…”