Frequently Asked Questions about the GCNS materials. 

> Why am I having problems reading the source_ID in the fits or csv
files, it seems to be truncated?

The source_ID is a 64 bit integer and some programs in IDL
(e.g. mrdfits), csv readers (e.g. excel) or the astropy's fits ascii
table reader turn this number into a 32 bit integer which for some low
values is fine but for most values they get truncated. Try different
programs (a working version of mrdfits is here:
https://github.com/wlandsman/IDLAstro/blob/master/pro/mrdfits.pro
courtesy of Wayne Landsman), assign the source_ID as a character, or
use the .dat files that are ASCII.

> What solar motion did you adopt in your calculation of the U,V,W?

The UVW were found using the procedure and equations described in the
Section 3 and Appendix B. These equations naturally provide
heliocentric UVW values and we used the Besançon Galaxy model
simulations as priors. These simulations have explicitly used the
solar motions (Usun, Vsun, Wsun) = (11.3, 7.0, 7.1) km/s but as
described in Appendix B they were "enforced" as Gaussian Mixture Model
fits to the simulations. So the provided UVW are heliocentric. To move
the UVW to that with respect to the Galactic center then the user can
apply their preferred solar motion even if that is different to the
values used in the simulations. This we felt was the best way to both
avoid biases from inverting the parallaxes and to include the
correlation of the parallaxes and proper motions especially since the
priors only really come into play for those objects with large errors.
The user always has the option to re-determine the UVW using the
equations directly.


Typos/Errors in the published paper not caught before press. These are
corrected in the version in this area:
pg 06 Sect. 3,     : We inferred space   -> We inferred heliocentric space
pg 11 Sect. 4.2,   : Mizar		-> * ksi Uma
pg 16 Sect. 5.2,   : the probably of     -> the probability of 
pg 17 Fig. 17      : The red line        -> The orange line
pg 18 Fig. 19      : plane of fig 5.3    -> plane of Fig. 18
pg 19 Sect. 5.3.1  : and 6 in fig 5.3    -> and 6 in Fig. 18
pg 19 Sect. 5.3.1  : panel of Fig. 5.3   -> panel of Fig. 18
pg 19 Sect. 5.3.1  : shown in fig 5.3    -> shown in Fig. 18
pg 19 Sect. 5.3.2, : magenta		-> orange
pg 27 Sect. 5.6    : shown in Fig. 9     -> shown in Fig. 8
pg 33 Sect. 6,     : 74,431 		-> 74,281
pg 40 App. A2,     : parallax_over_error -> abs(parallax_over_error)
Acknowledgements    2018/06/M/ST9/00311 -> 2018/30/M/ST9/00311