What does the five-pointed sign on the plane mean?

It does not mean certification

It means that the airline has joined the Star Alliance (STAR ??ALLIANCE).

Introduction

Star Alliance (STAR ??ALLIANCE) is an international airline alliance formally established on May 14, 1997. It initially consisted of five large international airlines belonging to different countries. Airlines form alliances to strengthen the competitiveness of alliance members by sharing software and hardware resources and route networks. Star Alliance's slogan is "The way the Earth connects", replacing the previous "The airline network for Earth".

The current membership of Star Alliance has grown to 26 member airlines, making it the oldest and largest aviation strategic alliance in the world so far. Alliance member airlines cover routes on five continents around the world, making Star Alliance's global aviation network more extensive and complete. Star Alliance's huge flight route network covers more than 170 countries and nearly 1,070 destinations.

I won’t list the detailed information one by one. If you want to know more: /view/131638.html?wtp=tt

Two airlines in my country have joined the Star Alliance. , are Air China and Shanghai Airlines. In addition, similar alliances include SkyTeam Alliance, Wings Alliance (Wings Alliance later merged with SkyTeam Alliance), etc.