Object Oriented Scripting is just Object Oriented Programming (classes, encapsulation, polymorphism, inheritance, and so forth) with a scripting language like Perl, PHP, Python, or Ruby. All four of those languages have interpreters that run the source code directly without turning it into compiled bytecode or compiled object code first, and all four have some mechanism for object oriented programming.
Java and C# are Object Oriented Programming Languages that get turned into bytecode, and are run through virtual machines (the Java Virtual Machine or the Microsoft dot NET framework, respectively).
C++ and Objective C are Object Oriented Programming Languages that get compiled directly into machine code.
Actually, Python does compile into byte code as it runs your code ( turns .py file into a .pyc file) so I suppose the byte code thing isn't a proper differentiator, assuming that we agree about Python being an object-oriented scripting language.
Personally, I (implicitly) define a "scripting language" as one that lets you write code without defining classes, main methods, etc. imposed structures.
For example, this is a Ruby script that doesn't have any sign of classes, functions, methods, etc. and it still executes:
You can't do this with Java, for example, which is why Java doesn't pass as a scripting language - you always need at least one class and a main method.
Continuing on this definition, an object-oriented scripting language is one that also allows you to use concepts such as objects (and, optionally, classes).