def is_period_alias(period):
    """
    Check if a given period is possibly an alias.

    Parameters
    ----------
    period : float
        A period to test if it is a possible alias or not.

    Returns
    -------
    is_alias : boolean
        True if the given period is in a range of period alias.
    """
    for i in range(1, 6):
        if 0.99 / float(i) < period < 1.004 / float(i):
            return True
        if 1.03 / float(i) < period < 1.04 / float(i):
            return True
        if 29.2 / float(i) < period < 29.9 / float(i):
            return True
        if 0.96465 / float(i) < period < 0.96485 / float(i):
            return True
        if 0.96725 / float(i) < period < 0.96745 / float(i):
            return True
        if 0.9819 / float(i) < period < 0.9823 / float(i):
            return True
        if 1.01034 / float(i) < period < 1.01076 / float(i):
            return True
        if 1.01568 / float(i) < period < 1.01604 / float(i):
            return True
        if 1.01718 / float(i) < period < 1.01742 / float(i):
            return True
        if 0.50776 / float(i) < period < 0.50861 / float(i):
            return True
        if 0.96434 / float(i) < period < 0.9652 / float(i):
            return True
        if 0.96688 / float(i) < period < 0.96731 / float(i):
            return True
        if 1.0722 / float(i) < period < 1.0729 / float(i):
            return True
        if 27.1 / float(i) < period < 27.5 / float(i):
            return True
    return False
