A fresh look at the RR Lyrae population in the Draco dwarf spheroidal
  galaxy with Gaia
  We present a catalogue of 285 RR Lyrae stars (RRLs) in the Draco dwarf
spheroidal galaxy (dSph), obtained by combining data from a number of different
surveys including the second data release (DR2) of the European Space Agency
(ESA) cornerstone mission Gaia. We have determined individual distances to the
RRLs in our sample using for the first time a Gaia G-band
luminosity-metallicity relation (MG - [Fe/H]) and study the structure of the
Draco dSph as traced by its RRL population. We find that the RRLs located in
the western/south-western region of Draco appear to be closer to us, which may
be a clue of interaction between Draco and the Milky Way (MW). The average
distance modulus of Draco measured with the RRLs is 19.53 +/- 0.07 mag,
corresponding to a distance of 80.5 +/- 2.6 kpc, in good agreement with
previous determinations in the literature. Based on the pulsation properties of
the RRLs we confirm the Oosterhoff-intermediate nature of Draco. We present an
additional sample of 41 candidate RRLs in Draco, which we selected from the
Gaia DR2 catalogue based on the uncertainty of their G-band magnitudes.
Additional epoch data that will become available in the Gaia third data release
(DR3) will help to confirm whether these candidates are bona-fide Draco RRLs.
