html5 - Is button in header valid ? <h1><button> Caption </button></h1> -

is possible or not valid?

<h1>   <button>      caption   </button> </h1> 

this header heading of accordion. therefore button opens , closes accordion semantically header important chapters of page. suggest?

first of all, try w3c validator instead of opening new question every time want know if html valid.

now question - yes valid.