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  1. A Suslin line is defined to be a nonseparable ccc linearly ordered space.

  2. A topological space $X$ is said to be star countable if whenever $\mathscr{U}$ is an open cover of $X$, there is a countable subspace $K$ of $X$ such that $X = \operatorname{St}(K,\mathscr{U})$.

My question is this:

Must a Suslin line be star countable?

Thanks for your help.

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Yes, because a ccc ordered space is Lindelöf (classic fact; a Suslin line is an example of an ordered L-space: regular, hereditarily Lindelöf but not separable) and all Lindelöf spaces are star countable (trivial; pick a countable subcover and a point from each member).

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