Please use this identifier to cite or link to this item:
|Title:||Pushing the Limits, Episode 2: K2 Observations of Extragalactic RR Lyrae Stars in the Dwarf Galaxy Leo IV||Authors:||Molnár, L.
Moretti, Maria Ida
Kiss, L. L.
|Issue Date:||2015||Journal:||THE ASTROPHYSICAL JOURNAL||Number:||812||Issue:||1||First Page:||2||Abstract:||We present the first observations of extragalactic pulsating stars in the K2 ecliptic survey of the Kepler space telescope. The variability of all three RR Lyrae stars in the dwarf spheroidal galaxy Leo IV was successfully detected, at a brightness of Kp ≈ 21.5 mag, from data collected during Campaign 1. We identified one modulated star and another likely Blazhko candidate with periods of 29.8 ± 0.9 days and more than 80 days, respectively. EPIC 210282473 represents the first star beyond the Magellanic Clouds for which the Blazhko period and cycle-to-cycle variations in the modulation were unambiguously measured. The photometric [Fe/H] indices of the stars agree with earlier results that Leo IV is a very metal-poor galaxy. Two out of the three stars blend with brighter background galaxies in the K2 frames. We demonstrate that image subtraction can be reliably used to extract photometry from faint confused sources, which will be crucial not only for the K2 mission but also for future space photometric missions.||Acknowledgments:||We are grateful to the referee for constructive comments that helped to improve the paper. We thank the hospitality of the Veszprém Regional Centre of the Hungarian Academy of Sciences (MTA VEAB) where part of our work was carried out. Funding for the Kepler and K2 missions is provided by the NASA Science Mission directorate. The authors gratefully acknowledge the Kepler team, the Guest Observer Office, and Ball Aerospace, whose outstanding efforts have made these results possible. This project has been supported by the Lendület-2009, LP2012-31, and LP2014-17 Programs of the Hungarian Academy of Sciences and the Hungarian OTKA grants K-104607, and K-109276, and the NKFIH K-115709 grant of the Hungarian National Research, Development and Innovation Office. The research leading to these results has received funding from the ESA PECS Contract No. 4000110889/14/NL/NDe, and from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreements No. 269194 (IRSES/ASK) and No. 312844 (SPACEINN). L.M. was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences. V.R. acknowledges partial support by the project PRIN-MIUR (2010LY5N2T) “Chemical and dynamical evolution of the Milky Way and Local Group galaxies” (P.I.: F. Matteucci). All of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non- HST data is provided by the NASA Office of Space Science via grant NNX09AF08G and by other grants and contracts.||URI:||http://hdl.handle.net/20.500.12386/25930||URL:||https://iopscience.iop.org/article/10.1088/0004-637X/812/1/2||ISSN:||0004-637X||DOI:||10.1088/0004-637X/812/1/2||Bibcode ADS:||2015ApJ...812....2M||Fulltext:||open|
|Appears in Collections:||1.01 Articoli in rivista|
Show full item record
Files in This Item:
|Molnár_2015_ApJ_812_2.pdf||Pdf editoriale||1.9 MB||Adobe PDF||View/Open|
checked on Sep 25, 2020
checked on Sep 25, 2020
Items in DSpace are published in Open Access, unless otherwise indicated.