Distance mapping applied to four well-known planetary nebulae and a nova
  shell
  Accurate distance estimates of astrophysical objects such as planetary
nebulae (PNe), and nova and supernova remnants, among others, allow us to
constrain their physical characteristics, such as size, mass, luminosity, and
age. An innovative technique based on the expansion parallax method, the
so-called distance mapping technique (DMT), provides distance maps of expanding
nebulae as well as an estimation of their distances. The DMT combines the
tangential velocity vectors obtained from 3D morpho-kinematic models and the
observed proper motion vectors to estimate the distance. We applied the DMT to
four PNe (NGC 6702, NGC 6543, NGC 6302, and BD+30 3639) and one nova remnant
(GK Persei) and derived new distances in good agreement with previous studies.
New simple morpho-kinematic shape models were generated for NGC 6543, NGC 6302,
and NGC 6702, whereas for BD+30 3639 and GK Persei published models were used.
We demonstrate that the DMT is a useful tool to obtain distance values of PNe,
in addition to revealing kinematically peculiar regions within the nebulae.
Distances are also derived from the trigonometric Gaia parallaxes. The effect
of the non-negligible parallax offset in the second Gaia data release is also
discussed.
