A dataset provided by the European Space Agency

Name OT2_pkervell_2
Title The stellar wind of two Galactic Cepheids: a key to solve the evolutionary/pulsational mass discrepancy


DOI https://doi.org/10.5270/esa-y42j7dl
Author European Space Agency
Description Thanks to their Period-Luminosity law, Cepheids are among the most
important class of stars. The recent discovery of circumstellar envelopes
(CSEs) around Cepheids is an indication that many Cepheids, if not all,
are surrounded by CSEs. The bright classical Cepheids RS Pup and
delta Cephei are particularly interesting members of their famous
class of variable stars, as they are known to be surrounded by large
CSEs. Following our PACS and SPIRE imaging observations of the dusty
circumstellar envelopes of these two Galactic Cepheids in OT1, we
request spectroscopic observations of the same two targets to measure
the physical conditions and composition of their stellar winds. Our
scientific goal is to determine the physical conditions in the stellar
winds, and pinpoint, in combination with other observations, the mass
loss rate of these two benchmark stars. There is still today a significant
discrepancy between the Cepheid masses estimated from evolutionary
modeling, and pulsation modeling. The evolutionary modeling
systematically predicts higher masses than the ..instantaneous,
dynamical pulsating masses. This may indicate that massive stars
experience significant mass loss episodes during their Cepheid phase.
We aim at testing the hypothesis that pulsation driven stellar winds occur
during the crossing of the instability strip, and are at the origin
of this discrepancy.
Instrument PACS_PacsRangeSpec_point
Temporal Coverage 2012-12-04T04:30:29Z/2013-01-29T16:58:36Z
Version SPG v14.2.0
Mission Description Herschel was launched on 14 May 2009! It is the fourth 'cornerstone' mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
Creator Contact https://support.cosmos.esa.int/h®erschel/
Date Published 2013-07-29T15:43:37Z
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, 2013, The Stellar Wind Of Two Galactic Cepheids: A Key To Solve The Evolutionary/Pulsational Mass Discrepancy, SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-y42j7dl