Coryn Bailer-Jones, MPIA Heidelberg, calj@mpia.de, 27 March 2019

Data from "Future stellar flybys of the Voyager and Pioneer spacecraft"
by Bailer-Jones & Farnocchia.

Each file lists the stars that each spacecraft will encounter within a
distance (dmed) of 2pc, sorted by increasing values of this distance.
The encounter parameters - time, distance, velocity - are computed
from a set of 1000 Monte Carlo samples; here we report the median of
the distribution (as a point estimate), and the 5th and 95th
percentiles (as measures of uncertainty).  Stars with questionable
encounter solutions, for example due to potentially bogus astrometric
solutions or implausibly large radial velocities, have not been
removed from these tables.

The columns of each file are as follows. Those marked with as asterisk
are taken directly from the Gaia DR2 gaia_source table, and are
explained in the Gaia online documentation.

 1* source_id  Gaia DR2 source identifier
 2  tmed/kyr   median encounter time
 3  t5/kyr      5th percentile of encounter time
 4  t95/kyr    95th percentile of encounter time
 5  dmed/pc    median encounter 
 6  d5/pc       5th percentile of encounter distance
 7  d95/kyr    95th percentile of encounter distance
 8  vmed/km/s  median encounter velocity 
 9  v5/kms      5th percentile of encounter velocity
10  v95/km/s   95th percentile of encounter velocity
11* par/mas    parallax
12* epar/mas   uncertainty in the parallax
13  pm/mas/yr  total proper motion
14  epm/mas/yr uncertainty in the total proper motion (takes into account covariance)
15* rv/km/s    radial velocity (from Simbad if not in Gaia DR2)
16* erv/km/s   uncertainty in the radial velocity
17* G/mag      apparent G-band magnitude
18  M_G/mag    absolute G-band magnitude, assuming zero extinction and distance=1/parallax
19* BP-RP/mag  BP-RP colour
20  uwe        unit weight error (defined in Lindegren et al. 2018, A&A 616, A2)
21* Nvis       number of visibility periods
22* AEN/mas    astrometric excess noise
23* AENsig/mas significance of the astrometric excess noise
24* Nrv        number of radial velocity observations
25* l/deg      Galactic longitude
26* b/deg      Galactic latitude
