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See detailConception of a near-infrared spectrometer for ground-based observations of massive stars
Kintziger, Christian ULg; Desselle, Richard ULg; Loicq, Jerôme ULg et al

in Journal of Astronomical Telescopes, Instruments, and Systems (2017), 3(1), 015002

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument for stellar astrophysics. Starting from the derivation of theoretical relationships from the ... [more ▼]

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument for stellar astrophysics. Starting from the derivation of theoretical relationships from the scientific requirements and telescope characteristics, the entire optical design of the spectrograph is presented. Specific optical elements, such as a toroidal lens, are introduced to improve the instrument’s efficiency. Then the verification of predicted optical performances is investigated through optical analyses, such as resolution checking. [less ▲]

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See detailXMM-Newton : en route vers une autre décennie de découvertes
Rauw, Grégor ULg

Article for general public (2017)

Au mois de décembre 2016, cela faisait 17 ans que XMM-Newton fut lancé par une fusée Ariane V. Equipé de ses trois modules miroirs comportant chacun 58 miroirs imbriqués les uns dans les autres, XMM ... [more ▼]

Au mois de décembre 2016, cela faisait 17 ans que XMM-Newton fut lancé par une fusée Ariane V. Equipé de ses trois modules miroirs comportant chacun 58 miroirs imbriqués les uns dans les autres, XMM-Newton est à l’affût de l’émission X de sources cosmiques de tout genre. Malgré sa longévité, XMM-Newton reste à ce jour un des observatoires les plus sollicités au monde. Chaque année, les astrophysiciens proposent des programmes d’observation qui totalisent à peu près 6 fois le temps d’observation disponible! La compétition pour les observations avec XMM est donc très rude. Et a priori cela pourrait continuer encore comme cela pendant quelques années. De fait, les réserves de carburant et la performance des panneaux solaires indiquent que la mission pourrait encore fonctionner au moins 10 ans si les budgets le permettent1! [less ▲]

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See detailObservational signatures of past mass-exchange episodes in massive binaries : The cases of HD17505 and HD206267
Raucq, Françoise ULg; Rauw, Grégor ULg

Conference (2016, December 19)

Mass and angular momentum exchanges through Roche Lobe Overflow interactions within close massive binaries are known to play an important role in the subsequent evolution of the components of such systems ... [more ▼]

Mass and angular momentum exchanges through Roche Lobe Overflow interactions within close massive binaries are known to play an important role in the subsequent evolution of the components of such systems, and produce several observational signatures, such as asynchronous rotation and altered chemical compositions, that remain once the stars detach again. We have started to investigate these effects in a sample of massive O-star binaries that are thought to have previously experienced a Case A Roche Lobe Overflow episode. Using phase-resolved spectroscopy, we perform the disentangling of the optical spectra of the two stars. The reconstructed primary and secondary spectra are then analysed with the CMFGEN model atmosphere code to determine stellar parameters such as the effective temperatures, surface gravities and rotational velocities, and to constrain the chemical composition of the components. In this contribution, we present the results of our analyses of the triple system HD17505 ([O7V + O7V, P = 8.57 days] + O6.5III). We also present the first results of our analyses of the triple system HD206267 ([O6.5V + O9.5V,P = 3.71 days] + OB). [less ▲]

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See detailGaia Data Release 1. Summary of the astrometric, photometric, and survey properties
Gaia Collaboration; Brown, A. G. A.; Vallenari, A. et al

in Astronomy and Astrophysics (2016), 595

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. <BR ... [more ▼]

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. <BR /> Aims: A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. <BR /> Methods: The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. <BR /> Results: Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the Hipparcos and Tycho-2 catalogues - a realisation of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of 3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr[SUP]-1[/SUP] for the proper motions. A systematic component of 0.3 mas should be added to the parallax uncertainties. For the subset of 94 000 Hipparcos stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr[SUP]-1[/SUP]. For the secondary astrometric data set, the typical uncertainty of the positions is 10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to 0.03 mag over the magnitude range 5 to 20.7. <BR /> Conclusions: Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data. [less ▲]

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See detailThe Gaia mission
Gaia Collaboration; Prusti, T.; de Bruijne, J. H. J. et al

in Astronomy and Astrophysics (2016), 595

Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept ... [more ▼]

Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page. <A href="http://www.cosmos.esa.int/gaia">http://www.cosmos.esa.int/gaia</A> [less ▲]

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See detailApsidal motion in the massive binary HD 152218
Rauw, Grégor ULg; Rosu, S.; Noels-Grötsch, Arlette ULg et al

in Astronomy and Astrophysics (2016), 594(A33), 1-12

Massive binary systems are important laboratories in which to probe the properties of massive stars and stellar physics in general. In this context, we analysed optical spectroscopy and photometry of the ... [more ▼]

Massive binary systems are important laboratories in which to probe the properties of massive stars and stellar physics in general. In this context, we analysed optical spectroscopy and photometry of the eccentric short-period early-type binary HD 152218 in the young open cluster NGC 6231. We reconstructed the spectra of the individual stars using a disentangling code. The individual spectra were then compared with synthetic spectra obtained with the CMFGEN model atmosphere code. We furthermore analysed the light curve of the binary and used it to constrain the orbital inclination and to derive absolute masses of (19.8 ± 1.5) and (15.0 ± 1.1) M⊙. Combining radial velocity measurements from over 60 yr, we show that the system displays apsidal motion at a rate of (2.04 ± .24)°/yr. Solving the Clairaut-Radau equation, we used stellar evolution models, obtained with the CLES code, to compute the internal structure constants and to evaluate the theoretically predicted rate of apsidal motion as a function of stellar age and primary mass. In this way, we determine an age of 5.8 ± 0.6 Myr for HD 152218, which is towards the higher end of, but compatible with, the range of ages of the massive star population of NGC 6231 as determined from isochrone fitting. [less ▲]

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See detailX-ray and optical spectroscopy of the massive young open cluster IC 1805
Rauw, Grégor ULg; Nazé, Yaël ULg

in Astronomy and Astrophysics (2016), 594(A82), 19

Context. Very young open clusters are ideal places to study the X-ray properties of a homogeneous population of early-type stars. In this respect, the IC 1805 open cluster is very interesting as it hosts ... [more ▼]

Context. Very young open clusters are ideal places to study the X-ray properties of a homogeneous population of early-type stars. In this respect, the IC 1805 open cluster is very interesting as it hosts the O4 If+ star HD 15570 thought to be in an evolutionary stage intermediate between a normal O-star and a Wolf-Rayet star. Aims: Such a star could provide a test for theoretical models aiming at explaining the empirical scaling relation between the X-ray and bolometric luminosities of O-type stars. Methods: We have observed IC 1805 with XMM-Newton and further collected optical spectroscopy of some of the O-star members of the cluster. Results: The optical spectra allow us to revisit the orbital solutions of BD+60° 497 and HD 15558, and provide the first evidence of binarity for BD+60° 498. X-ray emission from colliding winds does not appear to play an important role among the O-stars of IC 1805. Notably, the X-ray fluxes do not vary significantly between archival X-ray observations and our XMM-Newton pointing. The very fast rotator BD+60° 513, and to a lesser extent the O4 If+ star HD 15570 appear somewhat underluminous. Whilst the underluminosity of HD 15570 is only marginally significant, its amplitude is found to be compatible with theoretical expectations based on its stellar and wind properties. A number of other X-ray sources are detected in the field, and the brightest objects, many of which are likely low-mass pre-main sequence stars, are analyzed in detail. [less ▲]

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See detailLa malédiction X a encore frappé!
Rauw, Grégor ULg

Article for general public (2016)

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See detailX-ray emission from interacting wind massive binaries: A review of 15 years of progress
Rauw, Grégor ULg; Nazé, Yaël ULg

in Advances in Space Research (2016), 58

Previous generations of X-ray observatories revealed a group of massive binaries that were relatively bright X-ray emitters. This was attributed to emission of shock-heated plasma in the wind-wind ... [more ▼]

Previous generations of X-ray observatories revealed a group of massive binaries that were relatively bright X-ray emitters. This was attributed to emission of shock-heated plasma in the wind-wind interaction zone located between the stars. With the advent of the current generation of X-ray observatories, the phenomenon could be studied in much more detail. In this review, we highlight the progress that has been achieved in our understanding of the phenomenon over the last 15 years, both on theoretical and observational grounds. All these studies have paved the way for future investigations using the next generation of X-ray satellites that will provide crucial information on the X-ray emission formed in the innermost part of the wind-wind interaction. [less ▲]

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See detailConception of a near-IR spectrometer for ground-based observations of massive stars
Kintziger, Christian ULg; Desselle, Richard ULg; Loicq, Jerôme ULg et al

in Proc. SPIE Volume 9908 Ground-based and Airborne Instrumentation for Astronomy VI (2016, August 09)

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships ... [more ▼]

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships from the scientific requirements and telescope characteristics, the entire optical design of the spectrograph is presented. Specific optical elements, such as a toroidal lens, are introduced to improve the instrument’s performances. Then, the verification of predicted optical performances is investigated through optical analyses such as resolution checking. Eventually, the star positioning system onto the central fiber core is explained. [less ▲]

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See detailThe Athena X-ray Integral Field Unit (X-IFU)
Barret, Didier; Trong, Thien Lam; den Herder, Jan-Willem et al

in Proc. SPIE. 9905, Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray, 99052F. (August 17, 2016) (2016, August 01)

The X-ray Integral Field Unit (X-IFU) on board the Advanced Telescope for High-ENergy Astrophysics (Athena) will provide spatially resolved high-resolution X-ray spectroscopy from 0.2 to 12 keV, with 5 ... [more ▼]

The X-ray Integral Field Unit (X-IFU) on board the Advanced Telescope for High-ENergy Astrophysics (Athena) will provide spatially resolved high-resolution X-ray spectroscopy from 0.2 to 12 keV, with 5 arc second pixels over a field of view of 5 arc minute equivalent diameter and a spectral resolution of 2.5 eV up to 7 keV. In this paper, we first review the core scientific objectives of Athena, driving the main performance parameters of the X-IFU, namely the spectral resolution, the field of view, the effective area, the count rate capabilities, the instrumental background. We also illustrate the breakthrough potential of the X-IFU for some observatory science goals. Then we briefly describe the X-IFU design as defined at the time of the mission consolidation review concluded in May 2016, and report on its predicted performance. Finally, we discuss some options to improve the instrument performance while not increasing its complexity and resource demands (e.g. count rate capability, spectral resolution). The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with further ESA member state contributions from Belgium, Finland, Germany, Poland, Spain, Switzerland and two international partners from the United States and Japan. [less ▲]

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See detailThe filter wheel and filters development for the X-IFU instruments onboard Athena
Bozzo, E.; Barbera, M.; Genolet, L. et al

in den Herder, Jan-Willem, A.; Takahashi, Tadayuki; Bautz, Marshall (Eds.) Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series (2016, July 01)

Athena is the large mission selected by ESA in 2013 to investigate the science theme "Hot and Energetic Universe" and presently scheduled for launch in 2028. One of the two instruments located at the ... [more ▼]

Athena is the large mission selected by ESA in 2013 to investigate the science theme "Hot and Energetic Universe" and presently scheduled for launch in 2028. One of the two instruments located at the focus of the 12 m-long Athena telescope is the X-ray Integral Field Unit (X-IFU). This is an array of TES microcalorimeters that will be operated at temperatures of 50 mK in order to perform high resolution spectroscopy with an energy resolution down to 2.5 eV at energies < 7 keV. In order to cope with the large dynamical range of X-ray fluxes spanned by the celestial objects Athena will be observing, the X-IFU will be equipped with a filter wheel. This will allow the user to fine tune the instrument set-up based on the nature of the target, thus optimizing the scientific outcomes of the observation. A few positions of the filter wheel will also be used to host a calibration source and to allow the measurement of the instrument intrinsic background. [less ▲]

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See detailLa malédiction X a encore frappée
Rauw, Grégor ULg

Article for general public (2016)

Les superstitieux parleront sans doute d’une malédiction en évoquant le malheureux concours de circonstances qui a mené le 26 mars 2016 à la perte de la mission Hitomi de l’agence spatiale japonaise (JAXA ... [more ▼]

Les superstitieux parleront sans doute d’une malédiction en évoquant le malheureux concours de circonstances qui a mené le 26 mars 2016 à la perte de la mission Hitomi de l’agence spatiale japonaise (JAXA). Il s’agit en effet de la troisième tentative de la JAXA d’offrir aux astrophysiciens un instrument d’un genre nouveau : un calorimètre à rayons X1 . Hélas, à ce jour, toutes ces tentatives se sont soldées par des échecs! [less ▲]

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See detailObservational signatures of past mass-exchange episodes in massive binaries : The cases of LSS 3074 and HD 17505
Raucq, Françoise ULg; Rauw, Grégor ULg; Gosset, Eric ULg et al

Poster (2016, July)

Mass and angular momentum exchanges through Roche Lobe Overflow interactions within close massive binaries are known to play an important role in the subsequent evolution of the components of such systems ... [more ▼]

Mass and angular momentum exchanges through Roche Lobe Overflow interactions within close massive binaries are known to play an important role in the subsequent evolution of the components of such systems, and produce several observational signatures, such as asynchronous rotation and altered chemical compositions, that remain once the stars detach again. We have started to investigate these effects in a sample of massive O-star binaries that are thought to have previously experienced a Case A Roche Lobe Overflow episode. Using phase-resolved spectroscopy, we perform the disentangling of the optical spectra of the two stars. The reconstructed primary and secondary spectra re then analysed with the CMFGEN model atmosphere code to determine stellar parameters such as the effective temperatures, surface gravities and rotational velocities, and to constrain the chemical composition of the components. In this contribution, we present the results of our analyses of LSS 3074 (O5.5I + O6.5-7I, P = 2.1852 days), together with the analyses of its photometric lightcurve and orbital solution. We also present the first results of our analyses of the triple system HD17505 ([O7.5V + O7.5V, P = 8.57 days] + O6.5III). [less ▲]

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See detailConception of a near-IR spectrometer for ground-based observations of massive stars
Kintziger, Christian ULg; Desselle, Richard ULg; Loicq, Jerôme ULg et al

Poster (2016, June 27)

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships ... [more ▼]

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships from the scientific requirements and telescope characteristics, the entire optical design of the spectrograph is presented. Specific optical elements, such as a toroidal lens, are introduced to improve the instrument’s performances. Then, the verification of predicted optical performances is investigated through optical analyses such as resolution checking. Eventually, the star positioning system onto the central fiber core is explained. [less ▲]

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See detailTesting the theory of colliding winds: the periastron passage of 9 Sagittarii. I. X-ray and optical spectroscopy
Rauw, Grégor ULg; Blomme, R.; Nazé, Yaël ULg et al

in Astronomy and Astrophysics (2016), 589

Context. The long-period, highly eccentric O-star binary 9 Sgr, known for its non-thermal radio emission and its relatively bright X-ray emission, went through its periastron in 2013. <BR /> Aims: Such an ... [more ▼]

Context. The long-period, highly eccentric O-star binary 9 Sgr, known for its non-thermal radio emission and its relatively bright X-ray emission, went through its periastron in 2013. <BR /> Aims: Such an event can be used to observationally test the predictions of the theory of colliding stellar winds over a broad range of wavelengths. <BR /> Methods: We conducted a multi-wavelength monitoring campaign of 9 Sgr around the 2013 periastron. In this paper, we focus on X-ray observations and optical spectroscopy. <BR /> Results: The optical spectra allow us to revisit the orbital solution of 9 Sgr and to refine its orbital period to 9.1 years. The X-ray flux is maximum at periastron over all energy bands, but with clear differences as a function of energy. The largest variations are observed at energies above 2 keV, whilst the spectrum in the soft band (0.5-1.0 keV) remains mostly unchanged, indicating that it arises far from the collision region, in the inner winds of the individual components. The level of the hard emission at periastron clearly deviates from the 1 /r relation expected for an adiabatic wind-interaction zone, whilst this relation seems to hold at the other phases that are covered by our observations. The spectra taken at phase 0.946 reveal a clear Fe xxv line at 6.7 keV, but no such line is detected at periastron (φ = 0.000), although a simple model predicts a strong line that should be easily visible in the data. <BR /> Conclusions: The peculiarities of the X-ray spectrum of 9 Sgr could reflect the effect of radiative inhibition as well as a phase-dependent efficiency of particle acceleration on the shock properties. [less ▲]

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See detailHigh spectral resolution monitoring of Nova V339 Delphini with TIGRE (Corrigendum)
De Gennaro Aquino, I.; Schröder, K.-P.; Mittag, M. et al

in Astronomy and Astrophysics (2016), 589

The tags in Table 2, indicating the positions of the most prominent spectral features in Figs. 2a and b, were not corrected during the revision process. We include here the corrected table. The lines ... [more ▼]

The tags in Table 2, indicating the positions of the most prominent spectral features in Figs. 2a and b, were not corrected during the revision process. We include here the corrected table. The lines observed and identified in the spectra and the respective phases remain unchanged. [less ▲]

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See detailObservational signatures of past mass-exchange episodes in massive binaries: The case of HD 149 404
Raucq, Françoise ULg; Rauw, Gregor ULg; Gosset, Eric ULg et al

in Astronomy and Astrophysics (2016), 588

Context. Mass and momentum exchanges in close massive binaries play an important role in their evolution, and produce several observational signatures such as asynchronous rotation and altered chemical ... [more ▼]

Context. Mass and momentum exchanges in close massive binaries play an important role in their evolution, and produce several observational signatures such as asynchronous rotation and altered chemical compositions, that remain after the stars detach again. Aims: We investigated these effects for the detached massive O-star binary HD 149 404 (O7.5 If + ON9.7 I, P = 9.81 days), which is thought to have experienced a past episode of case A Roche-lobe overflow (RLOF). Methods: Using phase-resolved spectroscopy, we performed the disentangling of the optical spectra of the two stars. The reconstructed primary and secondary spectra were then analysed with the CMFGEN model atmosphere code to determine stellar parameters, such as the effective temperatures and surface gravities, and to constrain the chemical composition of the components. We complemented the optical study with the study of IUE spectra, which we compare to the synthetic binary spectra. The properties of the stars were compared to evolutionary models. Results: We confirmed a strong overabundance in nitrogen ([N/C] ~ 150[N/C][SUB]⊙[/SUB]) for the secondary and a slight nitrogen overabundance ([N/C] ~ 5[N/C][SUB]⊙[/SUB]) for the primary star. Comparing the two stars, we found evidence for asynchronous rotation, with a rotational period ratio of 0.50 ± 0.11. Conclusions: The hypothesis of a past case A RLOF interaction in HD 149 404 is most plausible to explain its chemical abundances and rotational asynchronicity. Some of the observed properties, such as the abundance pattern, are clearly a challenge for current case A binary evolution models, however. [less ▲]

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See detailThe α CrB binary system: A new radial velocity curve, apsidal motion, and the alignment of rotation and orbit axes
Schmitt, J. H. M. M.; Schröder, K.-P.; Rauw, Gregor ULg et al

in Astronomy and Astrophysics (2016), 586

We present a new radial velocity curve for the two components of the eclipsing spectroscopic binary α CrB. This binary consists of two main-sequence stars of types A and G in a 17.3599-day orbit ... [more ▼]

We present a new radial velocity curve for the two components of the eclipsing spectroscopic binary α CrB. This binary consists of two main-sequence stars of types A and G in a 17.3599-day orbit, according to the data from our robotic TIGRE facility that is located in Guanajuato, Mexico. We used a high-resolution solar spectrum to determine the radial velocities of the weak secondary component by cross-correlation and wavelength referencing with telluric lines for the strongly rotationally broadened primary lines (v sin(i) = 138 km s[SUP]-1[/SUP]) to obtain radial velocities with an accuracy of a few hundred m/s. We combined our new RV data with older measurements, dating back to 1908 in the case of the primary, to search for evidence of apsidal motion. We find an apsidal motion period between 6600 and 10 600 yr. This value is consistent with the available data for both the primary and secondary and is also consistent with the assumption that the system has aligned orbit and rotation axes. [less ▲]

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See detailMeasuring rotation periods of solar-like stars using TIGRE. A study of periodic CaII H+K S-index variability
Hempelmann, A.; Mittag, M.; Gonzalez-Perez, J. N. et al

in Astronomy and Astrophysics (2016), 586

Context. The rotation period of a star is a key parameter both for the stellar dynamo that generates magnetic fields as well as for stellar differential rotation. <BR /> Aims: We present the results from ... [more ▼]

Context. The rotation period of a star is a key parameter both for the stellar dynamo that generates magnetic fields as well as for stellar differential rotation. <BR /> Aims: We present the results from the first year of monitoring a sample of solar-like stars by the TIGRE facility in Guanajuato (Mexico), which will study rotation in solar analogs. <BR /> Methods: TIGRE is an automatically operating 1.2 m telescope equipped with an Échelle spectrograph with a spectral resolution of 20 000, which covers a spectral range of between 3800 and 8800 Å. A main task is the monitoring the stellar activity of cool stars, mainly in the emission cores of the CaII H and K lines. We observed a number of stars with a sampling between 1-3 days over one year. <BR /> Results: A total number of 95 stars were observed between August 1 2013 and July 31 2014, the total number of spectra taken for this program was appoximately 2700. For almost a third of the sample stars the number of observations was rather low (less than 20), mainly because of bad weather. Fifty-four stars show a periodic signal but often with low significance. Only 24 stars exhibit a significant period. We interpret these signals as stellar rotation. For about half of them the rotation periods were already previously known, in which case our period measurements are usually in good agreement with the literature values. Besides the periodic signals, trends are frequently observed in the time series. <BR /> Conclusions: TIGRE is obviously able to detect stellar rotation periods in the CaII H+K emission cores when the time series contains a sufficient number of data points. However, this is frequently not achievable during the wet summer season in Guanajuato. Hence, future estimates of rotation periods will concentrate on stars that are observable during the winter season from October until April. [less ▲]

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