Type II Cepheid

H-R diagram illustrating the location of Type II Cepheids in the instability strip

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]

  1. ^ a b Wallerstein, George (2002). "The Cepheids of Population II and Related Stars". The Publications of the Astronomical Society of the Pacific. 114 (797): 689–699. Bibcode:2002PASP..114..689W. doi:10.1086/341698.
  2. ^ Soszyński, I.; Udalski, A.; Szymański, M. K.; Kubiak, M.; Pietrzyński, G.; Wyrzykowski, Ł.; Szewczyk, O.; Ulaczyk, K.; Poleski, R. (2008). "The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. II.Type II Cepheids and Anomalous Cepheids in the Large Magellanic Cloud". Acta Astronomica. 58: 293. arXiv:0811.3636. Bibcode:2008AcA....58..293S.
  3. ^ Udalski, A.; Soszynski, I.; Szymanski, M.; Kubiak, M.; Pietrzynski, G.; Wozniak, P.; Zebrun, K. (1999). "The Optical Gravitational Lensing Experiment. Cepheids in the Magellanic Clouds. IV. Catalog of Cepheids from the Large Magellanic Cloud". Acta Astronomica. 49: 223–317. arXiv:astro-ph/9908317. Bibcode:1999AcA....49..223U.
  4. ^ Soszynski, I.; Poleski, R.; Udalski, A.; Szymanski, M. K.; Kubiak, M.; Pietrzynski, G.; Wyrzykowski, L.; Szewczyk, O.; Ulaczyk, K. (2008). "The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. I. Classical Cepheids in the Large Magellanic Cloud". Acta Astronomica. 58: 163. arXiv:0808.2210. Bibcode:2008AcA....58..163S.
  5. ^ Cite error: The named reference majaess09 was invoked but never defined (see the help page).
  6. ^ Macri, L. M.; Stanek, K. Z.; Bersier, D.; Greenhill, L. J.; Reid, M. J. (2006). "A New Cepheid Distance to the Maser-Host Galaxy NGC 4258 and Its Implications for the Hubble Constant". The Astrophysical Journal. 652 (2): 1133–1149. arXiv:astro-ph/0608211. Bibcode:2006ApJ...652.1133M. doi:10.1086/508530.
  7. ^ Ferrarese, Laura; Mould, Jeremy R.; Stetson, Peter B.; Tonry, John L.; Blakeslee, John P.; Ajhar, Edward A. (2007). "The Discovery of Cepheids and a Distance to NGC 5128". The Astrophysical Journal. 654 (1): 186–218. arXiv:astro-ph/0605707. Bibcode:2007ApJ...654..186F. doi:10.1086/506612.
  8. ^ Majaess, D. (2010). "The Cepheids of Centaurus A (NGC 5128) and Implications for H0". Acta Astronomica. 60 (2): 121. arXiv:1006.2458. Bibcode:2010AcA....60..121M.