The CoRoT Discovery of a Unique Triple-mode Cepheid in the Galaxy

Author(s)
Ennio Poretti, Annie Baglin, Werner Wolfgang Weiss
Abstract

The exploitation of the CoRoT treasure of stars observed in the exoplanetary field allowed the detection of a unusual triple-mode Cepheid in the Milky Way, CoRoT 0223989566. The two modes with the largest amplitudes and a period ratio of 0.80 are identified with the first (P

1 = 1.29 days) and second (P

2 = 1.03 days) radial overtones. The third period, which has the smallest amplitude but is able to produce combination terms with the other two, is the longest one (P

3 = 1.89 days). The ratio of 0.68 between the first-overtone period and the third period is the unusual feature. Its identification with the fundamental radial or a nonradial mode is discussed with respect to similar cases in the Magellanic Clouds. In both cases, the period triplet and the respective ratios make the star unique in our Galaxy. The distance derived from the period-luminosity relation and the galactic coordinates put CoRoT 0223989566 in the metal-rich environment of the "outer arm" of the Milky Way.

Organisation(s)
Department of Astrophysics
External organisation(s)
INAF Osservatorio Astronomico di Brera, Université de recherche Paris Sciences et Lettres, Université Paris VII - Paris-Diderot
Journal
The Astrophysical journal Letters
Volume
795
No. of pages
5
ISSN
2041-8205
DOI
https://doi.org/10.1088/2041-8205/795/2/L36
Publication date
11-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/6e00965f-4b83-4766-b020-1ec3e551870e