def retrieve_files(s3, short_name, date_str):
    """Retrieve a list of files from S3 bucket.
    
    Parameters
    ----------
    s3: S3FileSystem
        reference to S3 bucket to retrieve data from
    short_name:
        string short name of collection
    date_str: str
        string date and time to search for
        
    Returns
    -------
    list: list of strings
    """
    
    files = s3.glob(f"podaac-ops-cumulus-protected/{short_name}/{date_str}*.nc")
    return files