A luminaire for a track lighting system

A luminaire configured to be connected to a track of a track lighting system that is mounted to a mounting surface, wherein the luminaire comprises:

• a back surface facing the track when the luminaire is connected to said track;
• a planar light exit window arranged opposite to the back surface;
• a connector connected to the back surface and protruding a connector length away from the back surface, wherein the connector is configured to connect the luminaire mechanically and electrically to said track;
• at least one spacer element connected to the back surface and protruding a spacer length away from the back surface, wherein the at least one spacer element is configured to contact the mounting surface when the luminaire is connected to said track;
• wherein the connector length of the connector is adjustable from a first connector length to a second connector length;
• wherein the connector comprises:
• a foot connected to the back surface, a head configured to connect the luminaire mechanically and electrically to said track, an extendable member extending between said foot and said head;
• wherein the extendable member comprises a spring lock configured to switch between a locked state and a released state;
• wherein, in the locked state, the connector has the first connector length;
• wherein, in the released state, the connector has the second connector length;
• wherein the second connector length is shorter than the first connector length.