The requested vessel with name POLESTAR and MMSI:0 and IMO:7421992 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
POLESTAR 9364813 371811000 ZHENJIANGDAGANG Feb 20, 2018 13:54 UTC
POLESTAR N/A 235109755 Oct 30, 2017 15:18 UTC
POLESTAR1 N/A 431009853 Feb 12, 2018 04:11 UTC

Also, you may try to find the vessel in our comprehensive Vessels Database or track this ship on the map.