A dataset provided by the European Space Agency

Name: The Secret Lives of Cepheids: Exploring the X-ray Variability of delta Cep
Published: 2014-09-01T00:00:00Z
License: https://creativecommons.org/licenses/by-nc/3.0/igo

Proposal ID	072354
Title	The Secret Lives of Cepheids: Exploring the X-ray Variability of delta Cep
Download Data Associated to the proposal	https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0723540301 https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0723540401
DOI	https://doi.org/10.5270/esa-amro4ri
Principal Investigator, PI	Prof Edward Guinan
Abstract	We propose XMM-NEWTON EPIC observations of the prototype of Classical Cepheids,δ Cep, that we discovered is a variable X-ray and FUV emission-line star.The data will complement existing / approved HST FUV spectroscopy and completeX-ray phase coverage for this important star, which shows well-defined phasedchanges of FUV emission line fluxes from hot (10,000 300,000 K) plasmas. Theemissions peak between pulsation phases 0.75 1.05 and likely originate frompulsation-induced shocks. We request two 90 ksec exposures of δ Cep,covering the critical phase range of ~0.5 1.0, where X-ray emissions shouldpeak. These phases were not previously covered by XMM. The requestedobservations will provide crucial tests of atmospheric heating theories for Cepheids.
Publications	Discovery of the Hard Spectrum VHE gamma-Ray Source HESS J1641-463 \|Abramowski A. Aharonian F. et al. \| ApJ \| 794-1 \| 2014 \| 2014ApJ...794L...1A \| http://ui.adsabs.harvard.edu/#abs/2014ApJ...794L...1A 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 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 Nonthermal X-Rays from Pulsation-driven Shocks in Cepheids \|Fraschetti Federico Anastasopoulou Konstantina et al. \| ApJ \| 944-62 \| 2023 \| 2023ApJ...944...62F \| http://ui.adsabs.harvard.edu/#abs/2023ApJ...944...62F 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	2013-06-28T06:11:55Z/2013-07-03T08:00:22Z
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	2014-09-01T00:00:00Z
Last Update	2026-07-09
Keywords	"xmm newton epic", "xray emissions", "variable xray", "&# 948", "secret lives", "defined phased", "delta cep", "phase range", "EPIC", "HST", "XMM", "classical cepheids", "complement existing", "pulsation induced shoc", "pulsation phases", "xray variability", "atmospheric heating theories", "emissions peak"
Publisher And Registrant	European Space Agency
Credit Guidelines	European Space Agency, Prof Edward Guinan, 2014, 'The Secret Lives of Cepheids: Exploring the X-ray Variability of delta Cep', 21.51_20241115_1113, European Space Agency, https://doi.org/10.5270/esa-amro4ri
Rights	Data hosted in the ESA Space Science Archives are distributed under the CC BY-NC 3.0 IGO license.