Type II Cepheid
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Type II Cepheids are variable stars which pulsate with periods typically between 1 and 50 days.[1][2] They are population II stars: old, typically metal-poor, low mass objects.[1]
Like all Cepheid variables, Type IIs exhibit a relationship between the star's luminosity and pulsation period, making them useful as standard candles for establishing distances where little other data is available[3][4]
Longer period Type II Cepheids, which are more luminous, have been detected beyond the Local Group in the galaxies NGC 5128 and NGC 4258.[5][6][7][8]