Patricia J Lampens

Patricia J Lampens
Royal Observatory of Belgium · Astronomy & Astrophysics

PhD in Sciences, spec. Astronomy, Katholieke Universiteit Leuven, Belgium

About

228
Publications
11,062
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1,102
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Introduction
I conduct research in stellar physics. Over the years, I acquired relevant expertise in the observation and analysis of double and multiple stellar systems and variable stars. I focus on collecting accurate fundamental properties of double and multiple stars using space photometric and spectroscopic data, with a strong emphasis on systems with at least one pulsating star, in order to investigate the connection between the properties of the system and those of the intrinsic stellar pulsations...
Additional affiliations
March 2017 - September 2018
Royal Observatory of Belgium
Position
  • Head of Department
September 2009 - September 2020
Université Catholique de Louvain - UCLouvain
Position
  • Professor
Description
  • Co-teaching "Astronomy & Geophysics" (2nd Bachelor Math-Phys) Teaching& Examining (online with MS Teams)
January 1988 - present
Royal Observatory of Belgium
Position
  • Asteroseismology and Dynamics of Double and Multiple Stars
Education
October 1977 - July 1979
Katholieke Universiteit Leuven (KULeuven)
Field of study
  • Mathematics
October 1975 - July 1977
Katholieke Universiteit Leuven Afdeling Kortrijk (KULAK)
Field of study
  • Mathemathics

Publications

Publications (228)
Preprint
Since the end of 2018, the Transiting Exoplanet Survey Satellite (TESS) has provided stellar photometry to the astronomical community. We have used TESS data to study rotational modulation in the light curves of a sample of chemically peculiar stars with measured large-scale magnetic fields (mCP stars). In general, mCP stars show inhomogeneous dist...
Preprint
Full-text available
We present a new study of the Algol-type eclipsing binary system AS Eri based on the combination of the MOST and TESS light curves and a collection of very precise radial velocities obtained with the spectrographs HERMES operating at the Mercator telescope, La Palma, and TCES operating at the Alfred Jensch telescope, Tautenburg. The primary compone...
Article
We present a new study of the Algol-type eclipsing binary system AS Eri based on the combination of the MOST and TESS light curves and a collection of very precise radial velocities obtained with the spectrographs HERMES operating at the Mercator telescope, La Palma, and TCES operating at the Alfred Jensch telescope, Tautenburg. The primary compone...
Preprint
Full-text available
Oscillating eclipsing Algols (oEAs) are remarkable systems which allow us to determine accurate fundamental stellar parameters (mass, radius) and probe the stellar interiors through pulsations. TZ\,Dra is an oEA system containing a $\delta$ Scuti component. To examine particular characteristics of such close systems including pulsations and mass tr...
Article
Oscillating eclipsing Algols (oEAs) are remarkable systems which allow us to determine accurate fundamental stellar parameters (mass, radius) and probe the stellar interiors through pulsations. TZ Dra is an oEA system containing a δ Scuti component. To examine particular characteristics of such close systems including pulsations and mass transfer,...
Article
Evidence is presented that the far ultraviolet flux of ET And (A0Vp SiSr) recorded by the International Ultraviolet Explorer (IUE) was variable over a time scale of about one hour on 07 August 1979. In contrast, the spectra taken over 9 hours on 03 August 1979 do not show any flux variability. This behaviour is discussed using the light curve of ET...
Preprint
Full-text available
We present a study based on the high-resolution spectroscopy and K2 space photometry of five chemically peculiar stars in the region of the open cluster M44. The analysis of the high-precision photometric K2 data reveals that the light variations in HD 73045 and HD 76310 are rotational in nature and caused by spots or cloud-like co-rotating structu...
Article
Full-text available
We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. We identify 12 new roAp stars. Amongst these stars we discover the roAp star with the longest pulsation period, another with the shortes...
Preprint
Full-text available
We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. We identify 12 new roAp stars. Amongst these stars we discover the roAp star with the longest pulsation period, another with the shortes...
Preprint
Full-text available
Eclipsing systems are essential objects for understanding the properties of stars and stellar systems. Eclipsing systems with pulsating components are furthermore advantageous because they provide accurate constraints on the component properties, as well as a complementary method for pulsation mode determination, crucial for precise asteroseismolog...
Article
Context. Asteroseismic modelling of the internal structure of main-sequence stars born with a convective core has so far been based on homogeneous analyses of space photometric Kepler light curves of four years in duration, to which most often incomplete inhomogeneously-deduced spectroscopic information was added to break degeneracies. Aims. Our go...
Article
Full-text available
Eclipsing systems are essential objects for understanding the properties of stars and stellar systems. Eclipsing systems with pulsating components are furthermore advantageous because they provide accurate constraints on the component properties, as well as a complementary method for pulsation mode determination, crucial for precise asteroseismolog...
Preprint
Full-text available
The nominal Kepler mission provided very high-precision photometric data. Using these data, interesting phenomena such as spots, and ``hump and spike'' features were observed in the light curves of some normal A and metallic lined A stars (Am stars). However, the connection between such phenomena and the chemical peculiarity of the Am stars is stil...
Preprint
Full-text available
Asteroseismic modelling of the internal structure of main-sequence stars born with a convective core has so far been based on homogeneous analyses of space photometric Kepler light curves of 4 years duration, to which most often incomplete inhomogeneously deduced spectroscopic information was added to break degeneracies. We composed a sample of 111...
Article
Context. The presence of A/F-type Kepler hybrid stars extending across the entirety of the $\delta$ Scuti - $\gamma$ Doradus instability strips and beyond remains largely unexplained. In order to better understand these particular stars, we performed a multi-epoch spectroscopic study of a sample of 49 candidate A/F-type hybrid stars and one cool(er...
Preprint
Full-text available
The presence of A/F-type {\it Kepler} hybrid stars extending across the entire $\delta$ Sct-$\gamma$ Dor instability strips and beyond remains largely unexplained. In order to better understand these particular stars, we performed a multi-epoch spectroscopic study of 49 candidate A/F-type hybrid stars and one cool(er) hybrid object detected by the...
Experiment Findings
Full-text available
Article
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We present an analysis of the TESS-based light curve of the chemically peculiar A-type (Ap) star 21 Com (HD 108945). We used the SAP light curve with a time span of 27 d. A least-squares fi�t to the data with 10 harmonics yields a frequency of 0.48726 d^-1, which corresponds to a rotational period of 2.05229 d. Furthermore, we �find no evidence of...
Article
Aims. KIC 8975515 is a double-lined spectroscopic binary system with hybrid nature. Regular monitoring with the échelle spectrograph HERMES show that both components have matching atmospheric properties ( T eff ∼ 7400 K), and that one of them is a fast rotator ( v sin i = 162 versus 32 km s ⁻¹ ). Our aim is to study the Kepler light curve in order...
Preprint
Full-text available
Since the end of 2018, the Transiting Exoplanet Survey Satellite (TESS) provides high-quality space data on stellar photometry to the astronomical community. We present the results of an analysis of TESS photometric data for known slowly rotating magnetic chemically peculiar (mCP) stars. In general, mCP stars show an inhomogeneous distribution of e...
Article
Full-text available
We present the first asteroseismic results for δ Scuti and γ Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilize the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding variability and place them in the Hertzsprung-Russell diagram using Gaia DR2 data. Included within our sample are the epony...
Conference Paper
Full-text available
By means of a study based on multi-epoch, high-resolution spectra of 83 A/F-type candidate hybrid pulsating stars from the Kepler mission collected at various observatories, we derive a (lower) estimate of the fraction of hybrid stars which belong to spectroscopic binary and multiple systems. In the first part (49 hybrid stars), we derived a global...
Preprint
Full-text available
We present the first asteroseismic results for $\delta$ Scuti and $\gamma$ Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilise the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding variability and place them in the Hertzsprung-Russell diagram using Gaia DR2 data. Included within our sample...
Article
National Astronomical Research Institute of Thailand, Chiang Mai 50180, ThailandWe present the first results of a spectroscopic survey of southern and equatorial Algol-type eclipsing binary systems with mass-accreting pulsating components (oEA stars) using the 2.4-m Thai National Telescope (TNT) and the 10-m South African Large Telescope (SALT). Th...
Article
The Belgo-Indian Network for Astronomy & astrophysics (BINA) was initiated in 2014 to stimulate Belgian and Indian astronomers to collaborate on projects that are based on observations with the Indo-Belgian telescopes and other telescopes of interest. After the successful event of the 1st BINA workshop that took place in Nainital (India) in Novembe...
Article
Full-text available
In recent times, many new exoplanet and eclipsing binary candidates are reported, particularly from the archival data produced by the Kepler space mission destined to detect exoplanets in the Cygnus-Lyra region of the sky. In the framework of Belgo-Indian Network for Astronomy & Astrophysics (BINA) project, we also initiated a long-term programme ”...
Article
The oscillating Algol-type (oEA) stars are the former secondaries of evolved, semi-detached eclipsing binaries which are (still) undergoing mass transfer and form a newly detected class of pulsators close to the main sequence. Their unique feature consists of mass accretion onto the atmosphere of the pulsating star. Mass accretion affects the mass,...
Preprint
Full-text available
We present a new asteroseismic analysis of KIC~6048106, a \textit{Kepler} Algol-type eclipsing binary star in a circularized orbit with $P_\rm{orb}$=1.559361$\pm$0.000036~d. Based on a physical model for the binary and its corresponding set of fundamental parameters, ($T_\rm{eff}=7033\pm187~K, ~M_\rm{1}=1.55\pm0.11M_{\odot}$ and $T_\rm{eff}=4522\pm...
Article
We present the results of an analysis of photometric time-series observations for NGC 2126 acquired during the years 2004, 2013 and 2015. NGC 2126 is an intermediate-age open cluster which has a population of stars inside the δ Scuti instability strip. The main purpose is to search for new variable stars, to study their light curves and pulsation s...
Article
Full-text available
We present a new asteroseismic analysis of KIC 6048106, a Kepler Algol-type eclipsing binary star in a circularized orbit with Porb = 1.559361 ± 0.000036 d. Based on a physical model for the binary and its corresponding set of fundamental parameters (Teff = 7033 ± 187 K, M1 = 1.55 ± 0.11 M ☉ , R1 = 1.58 ± 0.12 R ☉ and Teff = 4522 ± 103 K, M2 = 0.33...
Article
The Belgo-Indian Network for Astronomy and Astrophysics (BINA) is a collaboration between Indian and Belgian astronomical institutes with the main aim to optimize the scientific output of the Indo-Belgian telescopes, being the 4.0-m International Liquid Mirror Telescope and the 3.6-m Devasthal Optical Telescope. These new facilities are both locate...
Article
We present the results of an analysis of photometric time-series observations for NGC 2126 acquired at the Thai National Observatory (TNO) in Thailand and the Mount Lemmon Optical Astronomy Observatory (LOAO) in USA during the years 2004, 2013 and 2015. The main purpose is to search for new variable stars and to study the light curves of binary sys...
Article
We report on a study of 250 optical spectra for 50 bright A/F-type candidate hybrid pulsating stars from the Kepler field. Most of the spectra have been collected with the high-resolution spectrograph HERMES attached to the Mercator telescope, La Palma. We determined the radial velocities (RVs), projected rotational velocities, fundamental atmosphe...
Article
Full-text available
The 4-m International Liquid Mirror Telescope (ILMT) is presently (March-June 2017) being erected on the ARIES site in Devasthal (Uttarakhand). We describe and illustrate in the present paper its different components. The ILMT will be used in the Time Delayed Integration (TDI) mode to carry out a deep survey and high S/N photometric and astrometric...
Article
Full-text available
The A/F-type stars and pulsators ($\delta$ Scuti-$\gamma$ Dor) are in a critical regime where they experience the transition from radiative to convective transport of energy in their envelopes. Such stars can pulsate in both gravity and acoustic modes. Hence, the knowledge of their fundamental parameters along with their observed pulsation characte...
Article
Full-text available
We analysed photometric time series of the active, semidetached Algol-type system RZ Cas obtained in 1999–2009, in order to search for seasonal and short-term variations in the oscillation spectrum of RZ Cas A. The orbital period shows ±1 s cyclic variations on time-scales of 6–9 years. We detected six low-degree p-mode oscillations with periods be...
Article
Full-text available
Context. Hundreds of candidate hybrid pulsators of intermediate type A–F were revealed by recent space missions. Hybrid pulsators allow us to study the full stellar interiors, where both low-order p - and high-order g -modes are simultaneously excited. The true hybrid stars must be identified since other processes, related to stellar multiplicity o...
Article
Full-text available
We present the results of a combined analysis of photometric time series and spectroscopic observations for the semi-detached eclipsing binary AO Ser aimed to study physical parameters of the system. New CCD photometric light curves in the B and V bands and radial velocities of AO Ser are presented. The Wilson-Devinney technique was used to simulta...
Article
Full-text available
\delta$ Scuti stars are remarkable objects for asteroseismology. In spite of decades of investigations, there are still important questions about these pulsating stars to be answered, such as their positions in $\log$$T_{\rm eff}$ $-$ $\log g$ diagram, or the dependence of the pulsation modes on atmospheric parameters and rotation. Therefore, we pe...
Article
We report on the discovery of a planetary companion candidate with a minimum mass Msini = 4.6 M_J orbiting the K2 III giant star HD 175370 (KIC 007940959). This star was a target in our program to search for planets around a sample of 95 giant stars observed with Kepler. This detection was made possible using precise stellar radial velocity measure...
Article
The Kepler space mission provided a wealth of δ Sct–γ Dor hybrid candidates. While some may be genuine hybrids, others might be misclassified due to the presence of a binary companion or to rotational modulation caused by magnetism and related surface inhomogeneities. In particular, the Kepler δ Sct–γ Dor hybrid candidate HD 188774 shows a few low...
Article
Full-text available
This report covers the workings of Commission 26 over the triennial period 2012-2015 and is the last report of the Commission. Included are reports from Working Groups and the Commission 26 Circular; all of which will be continuing in Commission G1 ( Binary and Multiple Stars ). Also included is a report of the Splinter Meeting of Commissions 26, 4...
Article
Full-text available
We report the identification of 61.45 d−1 (711.2 μHz) oscillations, with amplitudes of 62.6 μmag, in KIC 4768731 (HD 225914) using Kepler photometry. This relatively bright (V = 9.17) chemically peculiar star with spectral type A5 Vp SrCr(Eu) has previously been found to exhibit rotational modulation with a period of 5.21 d. Fourier analysis reveal...
Article
Full-text available
Context. Several hundred candidate hybrid pulsators of type A–F have been identified from space-based observations. Their large number allows both statistical analyses and detailed investigations of individual stars. This offers the opportunity to study the full interior of the genuine hybrids, in which both low radial order p- and high-order g-mod...
Article
Full-text available
The Kepler space mission provided near-continuous and high-precision photometry of about 207,000 stars, which can be used for asteroseismology. However, for successful seismic modelling it is equally important to have accurate stellar physical parameters. Therefore, supplementary ground-based data are needed. We report the results of the analysis o...
Article
Full-text available
We are currently monitoring up to 40 Kepler candidate δ Scuti-γ Doradus (resp. γ Doradus-δ Scuti) hybrid stars in radial velocity in order to identify the physical cause behind the low frequencies observed in the periodograms based on the ultra-high accuracy Kepler space photometry. The presence of low frequency variability in unevolved or slightly...
Article
Full-text available
Reliable determination of the basic physical properties of hot emission-line binaries with Roche-lobe filling secondaries is important for developing the theory of mass exchange in binaries. It is a very hard task, however, which is complicated by the presence of circumstellar matter in these systems. So far, only a small number of systems with acc...
Article
Full-text available
Pulsating stars in binary systems are ideal laboratories to test stellar evolution and pulsation theory, since a direct, model-independent determination of component masses is possible. The high-precision CoRoT photometry allows a detailed view of the frequency content of pulsating stars, enabling detection of patterns in their distribution. The ob...
Article
Full-text available
We carried out an extensive observational study of the Slowly Pulsating B (SPB) star, HD 25558. The ≈2000 spectra obtained at different observatories, the ground-based and MOST satellite light curves revealed that this object is a double-lined spectroscopic binary with an orbital period of about nine years. The observations do not allow the inferen...
Article
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We carried out an extensive photometric and spectroscopic investigation of the SPB binary, HD 25558 (see Fig. 1 for the time and geographic distribution of the observations). The ~2000 spectra obtained at 13 observatories during 5 observing seasons, the ground-based multi-colour light curves and the photometric data from the MOST satellite revealed...
Article
Full-text available
The asteroseismic and planetary studies, like all research related to stars, need precise and accurate stellar atmospheric parameters as input. We aim at deriving the effective temperature (Teff), the surface gravity (log g), the metallicity ([Fe/H]), the projected rotational velocity (v sin i) and the MK type for 169 F-, G-, K- and M-type Kepler t...
Article
We present relative astrometry and differential photometry measurements for a sample of nearby southern orbital binaries making use of the technique of Adaptive Optics. The observations were made in December 2000, with the ADONIS camera mounted at the 3.6m ESO telescope from La Silla Observatory, equipped with the broad-band near-infrared filters (...
Article
We used high-quality Kepler photometry and recent spectroscopic data to investigate the Kepler target KIC 005988140 considering three possible scenario's: (1) binarity, (2) co-existence of δ Scuti- and γ Doradus-type oscillations, and (3) rotational modulation with spots over the stellar surface. Using spectrum synthesis, we derived improved atmosp...
Article
A total of 40 optical spectra taken in 2010 with the HERMES spectrograph attached to the 1.2-m Mercator telescope (Observatorio del Roque de los Muchachos, Spain) in the range 380-900nm and in 2011 with the Coude-Echelle spectrograph attached to the 2-m telescope at the Thueringer Landessternwarte Tautenburg (Germany) in the range 472-740nm is bein...
Article
Full-text available
We used high-quality Kepler photometry and spectroscopic data to investigate the Kepler binary candidate KIC 5988140. Using the spectrum synthesis method, we derived the fundamental parameters Teff, log g, [M/H], and v.sini and the abundances. Frequency analyses of both the photometric and the spectroscopic data were performed, revealing the same t...
Article
Full-text available
HD 50138 presents the B[e] phenomenon, but its nature is not clear yet. This star is known to present spectral variations, which have been associated with outbursts and shell phases. We analyze the line profile variability of HD 50138 and its possible origin, which provide possible hints to its evolutionary stage, so far said to be close to the end...
Article
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The predicted orbital period histogram of an sdB population is bimodal with a peak at short (< 10 days) and long (> 250 days) periods. Observationally, there are many short-period sdB systems known, but only very few long-period sdB binaries are identified. As these predictions are based on poorly understood binary interaction processes, it is of p...
Article
Full-text available
A total of 72 files related to the optical spectra taken within 8 observing nights with HERMES spectrograph, covering the photospheric HeI 4026Å and SiII 4128Å and 4131Å lines, the circumstellar [OI] 6364Å line, and the lines formed in the upper layers of the stellar atmosphere or very close to the stellar surface: SiII 6347Å and 6371Å, HeI 6678Å,...
Article
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432 maxima of 64 High-Amplitude Delta Scuti Stars (HADS) obtained from CCD observations, are presented. Observations of the newly discovered HADS GSC 3004-0870 are included. The object GSC 1924-1134 was found to be a double-mode HADS, while GSC 1621-1643, GSC 2847-586 and GSC 3490-814 were found to be multiperiodic pulsators. GSC 4556-1113 is showi...