Editing Cepheid variable (section)

=== Anomalous Cepheids ===
A group of pulsating stars on the instability strip have periods of less than 2 days, similar to RR Lyrae variables but with higher luminosities. Anomalous Cepheid variables have masses higher than type II Cepheids, RR Lyrae variables, and the Sun. It is unclear whether they are young stars on a "turned-back" horizontal branch, [[blue straggler]]s formed through [[mass transfer]] in binary systems, or a mix of both.<ref name=caputo>{{cite journal|bibcode=2004A&A...424..927C|title=Bright metal-poor variables: Why ''Anomalous'' Cepheids?|journal=[[Astronomy and Astrophysics]]|volume=424|issue=3|pages=927–934 |last1=Caputo|first1=F.|last2=Castellani|first2=V.|last3=Degl'Innocenti|first3=S.|last4=Fiorentino|first4=G.|last5=Marconi|first5=M. |year=2004|doi=10.1051/0004-6361:20040307|arxiv=astro.ph/0405395 |s2cid=45306570}}</ref><ref name=sosznytski>{{cite journal|bibcode=2008AcA....58..293S|title=The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. II.Type II Cepheids and Anomalous Cepheids in the Large Magellanic Cloud|journal=[[Acta Astronomica]]|volume=58|pages=293|last1=Soszyński|first1=I.|last2=Udalski|first2=A.|last3=Szymański|first3=M. K.|last4=Kubiak|first4=M.|last5=Pietrzyński|first5=G.|last6=Wyrzykowski|first6=Ł.|last7=Szewczyk|first7=O.|last8=Ulaczyk|first8=K.|last9=Poleski |first9=R.|year=2008|arxiv=0811.3636 }}</ref>