How to find list of messages published on particular topic?

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I am using turtlebot in gazebo which uses "scan" message for publishing laser scan data, by using rostopic type scan command I can find out type of the message i.e. sensor_msgs/LaserScan , Is there way to find names of all the messages published on particular topic ?

For example, Is there any way to find out that message named "scan" is published by turtlebot knowing only the topic name i.e. sensor_msgs/LaserScan ?

Thanks in advance.