A dataset provided by the European Space Agency

Name: The Secret X-ray Lives of Cepheids: Are Classical Cepheids X-ray Variables?
Published: 2011-05-21T00:00:00Z
License: https://creativecommons.org/licenses/by-nc/3.0/igo

Proposal ID	065478
Title	The Secret X-ray Lives of Cepheids: Are Classical Cepheids X-ray Variables?
Download Data Associated to the proposal	https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0654780201
DOI	https://doi.org/10.5270/esa-l5aakro
Principal Investigator, PI	Prof Edward Guinan
Abstract	We are now immersed in the middle of a stellar mystery: why (and how) areClassical Cepheids producing X-rays? We propose phase-constrained & betterexposed XMM observations in Cycle 9 to solve this mystery, and initiate a leapforward in our understanding of Cepheid atmospheres, pulsations, winds, shocksand internal structures. It is worth noting that: all three Cepheids observed todate by XMM have successfully been detected and, more importantly, our recentXMM results mark the first ever unambiguous X-ray detections of Cepheids. Themajor aim of this proposal is to obtain deeper XMM observations of twopreviously observed Cepheids (Polaris & beta Dor) at critical pulsation phasesto understand the mechanism(s) by which they produce X-rays.
Publications	The Secret Lives of Cepheids: A Multi-Wavelength Study of the Atmospheres and Real-Time Evolution of Classical Cepheids \|Engle Scott \| PhDT \| 0-45 \| 2015 \| 2015PhDT........45E \| http://ui.adsabs.harvard.edu/#abs/2015PhDT........45E The Million Optical - Radio/X-ray Associations (MORX) Catalogue \|Flesch Eric W. \| PASA \| 33-52 \| 2016 \| 2016PASA...33...52F \| http://ui.adsabs.harvard.edu/#abs/2016PASA...33...52F The Secret Lives of Cepheids: delta Cep---The Prototype of a New Class of Pulsating X-Ray Variable Stars \|Engle Scott G. Guinan Edward F. et al. \| ApJ \| 838-67 \| 2017 \| 2017ApJ...838...67E \| http://ui.adsabs.harvard.edu/#abs/2017ApJ...838...67E X-Ray UV and Optical Observations of Classical Cepheids: New Insights into Cepheid Evolution and the Heating and Dynamics of Their Atmospheres \|Engle Scott G. Guinan Edward F. \| JASS \| 29-181 \| 2012 \| 2012JASS...29..181E \| http://ui.adsabs.harvard.edu/#abs/2012JASS...29..181E Classification of 4XMM-DR9 sources by machine learning \|Zhang Yanxia Zhao Yongheng \| MNRAS \| 503-5263 \| 2021 \| 2021MNRAS.503.5263Z \| http://ui.adsabs.harvard.edu/#abs/2021MNRAS.503.5263Z X-Rays in Cepheids: Identifying Low-mass Companions of Intermediate-mass Stars \|Evans Nancy Remage Engle Scott et al. \| ApJ \| 938-153 \| 2022 \| 2022ApJ...938..153E \| http://ui.adsabs.harvard.edu/#abs/2022ApJ...938..153E The XMM-Newton Line Emission Analysis Program (X-LEAP). I. Emission-line Survey of O VII O VIII and Fe L-shell Transitions \|Pan Zeyang Qu Zhijie et al. \| ApJS \| 271-62 \| 2024 \| 2024ApJS..271...62P \| http://ui.adsabs.harvard.edu/#abs/2024ApJS..271...62P From Active Stars to Black Holes: A Discovery Tool for Galactic X-Ray Sources \|Rodriguez Antonio C. \| PASP \| 136-054201 \| 2024 \| 2024PASP..136e4201R \| http://ui.adsabs.harvard.edu/#abs/2024PASP..136e4201R Robust constraints on feebly interacting particles using XMM-Newton \|Luque Pedro De la Torre Balaji Shyam \| PhRvD \| 109-L101305 \| 2024 \| 2024PhRvD.109j1305L \| http://ui.adsabs.harvard.edu/#abs/2024PhRvD.109j1305L Multimessenger search for electrophilic feebly interacting particles from supernovae \|Luque Pedro De la Torre Balaji Shyam \| PhRvD \| 109-103028 \| 2024 \| 2024PhRvD.109j3028L \| http://ui.adsabs.harvard.edu/#abs/2024PhRvD.109j3028L Importance of Cosmic-Ray Propagation on Sub-GeV Dark Matter Constraints \|De la Torre Luque Pedro Balaji Shyam \| ApJ \| 968-46 \| 2024 \| 2024ApJ...968...46D \| http://ui.adsabs.harvard.edu/#abs/2024ApJ...968...46D New 511 keV Line Data Provide Strongest sub-GeV Dark Matter Constraints \|De la Torre Luque Pedro Balaji Shyam \| ApJ \| 973-L6 \| 2024 \| 2024ApJ...973L...6D \| http://ui.adsabs.harvard.edu/#abs/2024ApJ...973L...6D
Instrument	EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage	2010-05-01T09:12:01Z/2010-05-01T19:43:10Z
Version	21.51_20241115_1113
Mission Description	The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
Creator Contact	https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk
Date Published	2011-05-21T00:00:00Z
Last Update	2026-07-09
Keywords	"leap forward", "cepheid atmospheres", "secret xray lives", "beta dor", "worth noting", "internal structures", "deeper xmm", "XMM", "cepheids polaris", "phase constrained", "pulsation phases", "exposed xmm", "unambiguous xray detections"
Publisher And Registrant	European Space Agency
Credit Guidelines	European Space Agency, Prof Edward Guinan, 2011, 'The Secret X-ray Lives of Cepheids: Are Classical Cepheids X-ray Variables?', 21.51_20241115_1113, European Space Agency, https://doi.org/10.5270/esa-l5aakro
Rights	Data hosted in the ESA Space Science Archives are distributed under the CC BY-NC 3.0 IGO license.