Publications (128)
The BRITE-Constellation Nanosatellite Space Mission And Its First Scientific Results
G. Handler, A. Pigulski, W. W. Weiss +15
The BRIght Target Explorer (BRITE) Constellation is the first nanosatellite mission applied to astrophysical research. Five satellites in low-Earth orbits perform precise optical t…
The BRITE Constellation nanosatellite mission: Testing, commissioning and operations
H. Pablo, G. N. Whittaker, A. Popowicz +27
BRITE (BRIght Target Explorer) Constellation, the first nanosatellite mission applied to astrophysical research, is a collaboration among Austria, Canada and Poland. The fleet of s…
Characterizing the variability of a sample of massive stars in eclipsing binaries
C. I. Eze, G. Handler, F. Kahraman AliçavuŠ+2
Massive stars exhibit a perplexing mismatch between their inferred masses from different observational techniques, posing a significant challenge to our understanding of stellar ev…
Catalogue of BRITE-Constellation targets I. Fields 1 to 14 (November 2013 - April 2016)
K. Zwintz, A. Pigulski, R. Kuschnig +25
The BRIght Target Explorer (BRITE) mission collects photometric time series in two passbands aiming to investigate stellar structure and evolution. Since their launches in the year…
First Kepler results on compact pulsators II: KIC 010139564, a new pulsating subdwarf B (V361 Hya) star with an additional low-frequency mode
Steven D. Kawaler, M. D. Reed, A. C. Quint +13
We present the discovery of nonradial pulsations in a hot subdwarf B star based on 30.5 days of nearly continuous time-series photometry using the \emph{Kepler} spacecraft. KIC 010…
Magnetic B stars observed with BRITE: Spots, magnetospheres, binarity, and pulsations
G. A. Wade, D. H. Cohen, C. Fletcher +16
Magnetic B-type stars exhibit photometric variability due to diverse causes, and consequently on a variety of timescales. In this paper we describe interpretation of BRITE photomet…
The 2003-4 multisite photometric campaign for the Beta Cephei and eclipsing star 16 (EN) Lacertae with an Appendix on 2 Andromedae, the variable comparison star
M. Jerzykiewicz, G. Handler, J. Daszynska-Daszkiewicz +26
A multisite photometric campaign for the Beta Cephei and eclipsing variable 16 Lacertae is reported. 749 h of high-quality differential photoelectric Stromgren, Johnson and Geneva…
First Kepler results on compact pulsators III: Subdwarf B stars with V1093~Her and hybrid (DW~Lyn) type pulsations
M. D. Reed, S. D. Kawaler, R. H. Ostensen +12
We present the discovery of nonradial pulsations in five hot subdwarf B (sdB) stars based on 27 days of nearly continuous time-series photometry using the Kepler spacecraft. We fin…
The photometric behaviour of the peculiar PG1159 star HS2324+3944 at high frequency resolution
R. Silvotti, S. Dreizler, G. Handler +1
We present the results from 135 hours of nearly continuous time series photometry on the ``hybrid'' (H-rich) PG1159 variable star HS2324+3944, obtained in August-September 1997. Th…
On the relationship between the Delta Scuti and Gamma Doradus pulsators
G. Handler, R. R. Shobbrook
We searched for Delta Scuti-type pulsations amongst known and candidate Gamma Doradus stars. We acquired 270 h of observations and monitored a total of 26 stars. One target, HD 209…
Short-term variability and mass loss in Be stars III. BRITE and SMEI satellite photometry of 28 Cygni
D. Baade, A. Pigulski, Th. Rivinius +11
The BRITE Constellation of nanosatellites obtained mmag photometry of 28 Cygni for 11 months in 2014-2016. Observations with the Solar Mass Ejection Imager in 2003-2010 and 118 H$Î…
A multisite photometric study of two unusual Beta Cep stars: the magnetic V2052 Oph and the massive rapid rotator V986 Oph
G. Handler, R. R. Shobbrook, K. Uytterhoeven +15
We report a multisite photometric campaign for the Beta Cep stars V2052 Oph and V986 Oph. 670 hours of high-quality differential photoelectric Stromgren, Johnson and Geneva time-se…
Eclipsing binary systems with Cephei components. V1216 Sco
A. Miszuda, C. I. Eze, F. Kahraman Alicavus +2
We present a detailed analysis of the high-mass binary system V1216 Sco, an eclipsing Algol-type binary hosting a Cephei pulsator, with an orbital period of 3.92 days. This sy…
Planet Hunters X. KIC 8462852 - Where's the Flux?
T. S. Boyajian, D. M. LaCourse, S. A. Rappaport +46
Over the duration of the Kepler mission, KIC8462852 was observed to undergo irregularly shaped, aperiodic dips in flux of up to \%. The dipping activity can last for betwe…
The rapidly oscillating Ap star HD 99563 and its distorted dipole pulsation mode
G. Handler, W. W. Weiss, R. R. Shobbrook +9
We undertook a time-series photometric multi-site campaign for the rapidly oscillating Ap star HD 99563 and also acquired mean light observations over two seasons. The pulsations o…
The single-sided pulsator CO~Camelopardalis
D. W. Kurtz, G. Handler, S. A. Rappaport +10
CO~Cam (TIC 160268882) is the second ``single-sided pulsator'' to be discovered. These are stars where one hemisphere pulsates with a significantly higher amplitude than the other…
Revisiting the pulsational characteristics of the exoplanet host star Pictoris
K. Zwintz, D. R. Reese, C. Neiner +22
Exoplanet properties crucially depend on their host stars' parameters. In case the exoplanet host star shows pulsations, asteroseismology can be used for an improved description of…
TESS first look at evolved compact pulsators: Known ZZ Ceti stars of the southern ecliptic hemisphere as seen by TESS
Zs. Bognár, S. D. Kawaler, K. J. Bell +13
Context. We present our findings on 18 formerly known ZZ Ceti stars observed by the TESS space telescope in 120s cadence mode during the survey observation of the southern ecliptic…
Spectroscopy of hot Gamma Doradus and A-F hybrid Kepler candidates close to the hot border of the Delta Scuti instability strip
F. Kahraman Alicavus, E. Poretti, G. Catanzaro +4
If Gamma Dor-type pulsations are driven by the convective blocking mechanism, a convective envelope at a sufficient depth is essential. There are several hot Gamma Dor and hybrid s…
BRITE-Constellation photometry of $\bpi^5$ Orionis, an ellipsoidal SPB variable
M. Jerzykiewicz, A. Pigulski, G. Handler +5
Results of an analysis of the BRITE-Constellation photometry of the SB1 system and ellipsoidal variable Ori (B2\,III) are presented. In addition to the orbital light-variati…
Short-term variability and mass loss in Be stars IV. Two groups of closely spaced, approximately equidistant frequencies in three decades of space photometry of Puppis (B7-8 IIIe)
D. Baade, A. Pigulski, Th. Rivinius +13
In early-type Be stars, groups of nonradial pulsation (NRP) modes with numerically related frequencies may be instrumental for the release of excess angular momentum through mass-e…
Stellar masses from granulation and oscillations of 23 bright red giants observed by BRITE - Constellation
T. Kallinger, P. G. Beck, S. Hekker +11
Context: The study of stellar structure and evolution depends crucially on accurate stellar parameters. The photometry from space telescopes has provided superb data that allowed a…
BRITE observations of Centauri and Lupi, the first non-eclipsing members of the new class of nascent binaries
M. Jerzykiewicz, A. Pigulski, G. Michalska +8
Results of an analysis of the BRITE-Constellation and SMEI photometry and radial-velocity observations, archival and new, of two single-lined spectroscopic binary systems Cent…
Wildly Oscillating Stars -- Unexplained dense ridge-like frequency agglomerations in A and F type pulsators
V. Antoci, J. Labadie-Bartz, M. Swiech +14
We investigate the origin of the dense, ridge-like frequency clusters observed in a subset of A and F type pulsating stars, which we refer to as `wildly oscillating' stars (WOS). T…
Searching for solar-like oscillations in the delta Scuti star rho Puppis
V. Antoci, G. Handler, F. Grundahl +7
Despite the shallow convective envelopes of delta Scuti pulsators, solar-like oscillations are theoretically predicted to be excited in those stars as well. To search for such stoc…
Evolving pulsation of the slowly rotating magnetic Cep star CMa
G. A. Wade, A. Pigulski, S. Begy +11
Recent BRITE-Constellation space photometry of the slowly rotating, magnetic Cep pulsator CMa permits a new analysis of its pulsation properties. Analysis of the two-co…
Empirical Determination of Convection Parameters in White Dwarfs I : Whole Earth Telescope Observations of EC14012-1446
J. L. Provencal, M. H. Montgomery, A. Kanaan +55
We report on analysis of 308.3 hrs of high speed photometry targeting the pulsating DA white dwarf EC14012-1446. The data were acquired with the Whole Earth Telescope (WET) during…
uvbybeta photometry of early type open cluster and field stars
G. Handler
The beta Cephei stars and slowly pulsating B (SPB) stars are massive main sequence variables. The strength of their pulsational driving strongly depends on the opacity of iron-grou…
The ^12C(alpha,gamma)^16O Nuclear Reaction Rate from Asteroseismology of the DBV White Dwarf CBS 114
T. S. Metcalfe, G. Handler
We have identified seven independent pulsation modes in the helium-atmosphere variable (DBV) white dwarf star CBS 114, based on 65 hours of time-resolved CCD photometry from the 0.…
First Kepler results on compact pulsators I. Survey target selection and the first pulsators
R. H. Ãstensen, R. Silvotti, S. Charpinet +25
We present results from the first two quarters of a survey to search for pulsations in compact stellar objects with the Kepler spacecraft. The survey sample and the various methods…
Amplitude and frequency variability of the pulsating DB white dwarf stars KUV 05134+2605 and PG 1654+160 observed with the Whole Earth Telescope
G. Handler
We have acquired new time series photometry of the two pulsating DB white dwarf stars KUV 05134+2605 and PG 1654+160 with the Whole Earth Telescope. Additional single-site photomet…
Discovery and analysis of p-mode and g-mode oscillations in the A-type primary of the eccentric binary HD 209295
G. Handler, L. A. Balona, R. R. Shobbrook +8
We have discovered both intermediate-order gravity mode and low-order pressure mode pulsation in the same star, HD 209295. It is therefore both a Gamma Doradus and a Delta Scuti st…
Magnetic OB[A] Stars with TESS: probing their Evolutionary and Rotational properties (MOBSTER) - I. First-light observations of known magnetic B and A stars
A. David-Uraz, C. Neiner, J. Sikora +21
In this paper we introduce the MOBSTER collaboration and lay out its scientific goals. We present first results based on the analysis of nineteen previously known magnetic O, B and…
BRITEning up the Be Phenomenon
D. Baade, Th. Rivinius, A. Pigulski +13
Observations of 25 Ori much expand the picture derived of other early-type Be stars with BRITE and SMEI. Two instead of one difference frequencies rule the variability: (a) The low…
Pulsation of the Delta Scuti star Theta2 Tau: New multisite photometry and modelling of instability
M. Breger, A. A. Pamyatnykh, W. Zima +3
The results of a multisite photometric campaign of Theta2 Tau are reported. This binary system consists of evolved and main-sequence A stars inside the instability strip. The 12th…
New BRITE-Constellation observations of the roAp star Alpha Circini
W. W. Weiss, H. -E. Fröhlich, T. Kallinger +11
Chemically peculiar (CP) stars with a measurable magnetic field comprise the group of mCP stars. The pulsating members define the subgroup of rapidly oscillating Ap (roAp) stars, o…
Preparing the COROT space mission: incidence and characterisation of pulsation in the Lower Instability Strip
E. Poretti, R. Garrido, P. J. Amado +24
By pursuing the goal to find new variables in the COROT field-of-view we characterised a sample of stars located in the lower part of the instability strip. Our sample is composed…
Rotational modulation in TESS B stars
L. A. Balona, G. Handler, S. Chowdhury +6
Light curves and periodograms of 160 B stars observed by the TESS space mission and 29 main-sequence B stars from Kepler and K2 were used to classify the variability type. There ar…
Asteroseismology of the Beta Cephei star 12 (DD) Lacertae: photometric observations, pulsational frequency analysis and mode identification
G. Handler, M. Jerzykiewicz, E. Rodriguez +28
We report a multisite photometric campaign for the Beta Cephei star 12 Lacertae. 750 hours of high-quality differential photoelectric Stromgren, Johnson and Geneva time-series phot…
The Discovery of an Outburst and Pulsed X-ray Flux from SMC X-2 from RXTE Observations
R. H. D. Corbet, F. E. Marshall, M. J. Coe +2
Rossi X-ray Timing Explorer All Sky Monitor observations of SMC X-2 show that the source experienced an outburst in January to April 2000 reaching a peak luminosity of greater than…
Mass transfer and tidally tilted pulsation in the Algol-type system TZ Dra
F. Kahraman Alicavus, G. Handler, F. Alicavus +6
Oscillating eclipsing Algols (oEAs) are remarkable systems which allow us to determine accurate fundamental stellar parameters (mass, radius) and probe the stellar interiors throug…
Towards ensemble asteroseismology of the young open clusters Chi Persei and NGC 6910
S. Saesen, A. Pigulski, F. Carrier +71
As a result of the variability survey in Chi Persei and NGC6910, the number of Beta Cep stars that are members of these two open clusters is increased to twenty stars, nine in NGC6…
Asteroseismology and forced oscillations of HD 209295, the first member of two classes of pulsating star
G. Handler, L. A. Balona, R. R. Shobbrook +9
We report the discovery of both intermediate-order gravity mode and low-order pressure mode pulsation in the same star, HD 209295. It is therefore both a gamma Doradus and a delta…
The search for roAp stars: null results and new candidates from Stroemgren-Crawford photometry
E. Paunzen, G. Handler, K. Honkova +10
The rapidly oscillating Ap (roAp) stars exhibit pulsational photometric and/or radial velocity variations on time scales of several minutes, which are essential to test current pul…
The Kepler characterization of the variability among A- and F-type stars. I. General overview
K. Uytterhoeven, A. Moya, A. Grigahcene +38
The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds of A-F type stars. We present a first general characterization of the…
Detection of 75+ pulsation frequencies in the Delta Scuti star FG Vir
M. Breger, P. Lenz, V. Antoci +9
Extensive photometric multisite campaigns of the Delta Scuti variable FG Vir are presented. For the years 2003 and 2004, 926 hours of photometry at the millimag precision level wer…
Cepheid investigations using the Kepler space telescope
R. Szabó, L. Szabados, C. -C. Ngeow +35
We report results of initial work done on selected candidate Cepheids to be observed with the Kepler space telescope. Prior to the launch 40 candidates were selected from previous…
Kepler Asteroseismology Program: Introduction and First Results
Ronald L. Gilliland, T. M. Brown, J. Christensen-Dalsgaard +32
Asteroseismology involves probing the interiors of stars and quantifying their global properties, such as radius and age, through observationsof normal modes of oscillation. The te…
M-Dwarf Fast Rotators and the Detection of Relatively Young Multiple M-Star Systems
S. Rappaport, J. Swift, A. Levine +9
We have searched the Kepler light curves of ~3900 M-star targets for evidence of periodicities that indicate, by means of the effects of starspots, rapid stellar rotation. Several…
New Beta Cephei stars in the young open cluster NGC 637
G. Handler, S. Meingast
Studying stellar pulsations in open clusters offers the possibility to perform ensemble asteroseismology. The reasonable assumption that the cluster members have the same age, dist…
Kepler and TESS Observations of PG 1159-035
Gabriela Oliveira da Rosa, S. O. Kepler, Alejandro H. Córsico +11
PG 1159-035 is the prototype of the DOV hot pre-white dwarf pulsators. It was observed during the Kepler satellite K2 mission for 69 days in 59 s cadence mode and by the TESS satel…
Asteroseismology of KIC 11754974: a high-amplitude SX Phe pulsator in a 343-day binary system
S. J. Murphy, A. Pigulski, D. W. Kurtz +13
The candidate SX Phe star KIC 11754974 shows a remarkably high number of combination frequencies in the Fourier amplitude spectrum: 123 of the 166 frequencies in our multi-frequenc…
Gamma Doradus Stars: Defining a New Class of Pulsating Variables
A. B. Kaye, G. Handler, K. Krisciunas +2
In this paper we describe a new class of pulsating stars, the prototype of which is the bright, early, F-type dwarf, Gamma Doradus. These stars typically have between 1 and 5 perio…
Asteroseismic analysis of the roAp star alpha Circini: 84 days of high-precision photometry from the WIRE satellite
H. Bruntt, D. W. Kurtz, M. S. Cunha +8
We present a detailed study of the pulsation of alpha Circini, the brightest of the rapidly oscillating Ap stars. We have obtained 84 days of high-precision photometry from four ru…
Kepler photometry and optical spectroscopy of the ZZ Lep central star of the Planetary Nebula NGC 6826: rotational and wind variability
G. Handler, R. K. Prinja, M. A. Urbaneja +3
We present three years of long-cadence and over one year of short-cadence photometry of the central star of the Planetary Nebula NGC 6826 obtained with the Kepler spacecraft, and t…
2MASSJ0516288+260738: Discovery of the first eclipsing late K + Brown dwarf system?
S. L. Schuh, G. Handler, H. Drechsel +22
We report the discovery of a new eclipsing system less than one arcminute south of the pulsating DB white dwarf KUV 05134+2605. The object could be identified with the point source…
First Kepler results on compact pulsators V: Slowly pulsating subdwarf B stars in short-period binaries
S. D. Kawaler, M. D. Reed, R. H. Ãstensen +15
The survey phase of the Kepler Mission includes a number of hot subdwarf B (sdB) stars to search for nonradial pulsations. We present our analysis of two sdB stars that are found t…
The asteroseismological potential of the pulsating DB white dwarf stars CBS 114 and PG 1456+103
G. Handler, T. S. Metcalfe, M. A. Wood
We have acquired 65 h of single-site time-resolved CCD photometry of the pulsating DB white dwarf star CBS 114 and 62 h of two-site high-speed CCD photometry of another DBV, PG 145…
Discovery of a Nova-Like Cataclysmic Variable in the Kepler Mission Field
Kurtis A. Williams, Domitilla de Martino, Roberto Silvotti +6
We announce the identification of a new cataclysmic variable star in the field of the Kepler Mission, KIC J192410.81+445934.9. This system was identified during a search for compac…
Pulsational Mapping of Calcium Across the Surface of a White Dwarf
Susan E. Thompson, M. H. Montgomery, T. von Hippel +27
We constrain the distribution of calcium across the surface of the white dwarf star G29-38 by combining time series spectroscopy from Gemini-North with global time series photometr…
An asteroseismic test of diffusion theory in white dwarfs
T. S. Metcalfe, R. E. Nather, T. K. Watson +3
The helium-atmosphere (DB) white dwarfs are commonly thought to be the descendants of the hotter PG1159 stars, which initially have uniform He/C/O atmospheres. In this evolutionary…
The role of turbulent pressure as a coherent pulsational driving mechanism: the case of the delta Scuti star HD 187547
V. Antoci, M. Cunha, G. Houdek +6
HD 187547 was the first candidate that led to the suggestion that solar-like oscillations are present in delta Scuti stars. Longer observations, however, show that the modes interp…
Internal Gravity Waves in Massive Stars II: Frequency Analysis Across Stellar Mass
R. P. Ratnasingam, T. M. Rogers, S. Chowdhury +4
Stars with masses above 1.6 solar masses generally possess convective cores and radiative envelopes, which allows the propagation of outward-travelling internal gravity waves. We h…
Kepler observations of the beaming binary KPD 1946+4340
S. Bloemen, T. R. Marsh, R. H. Ãstensen +24
The Kepler Mission has acquired 33.5d of continuous one-minute photometry of KPD 1946+4340, a short-period binary system that consists of an sdB and a white dwarf. In the light cur…
Hybrid gamma Doradus - delta Scuti pulsators: New insights into the physics of the oscillations from Kepler observations
A. Grigahcene, V. Antoci, L. Balona +39
Observations of the pulsations of stars can be used to infer their interior structure and test theoretical models. The main sequence Doradus (Dor) and Scuti (Sct) stars w…
Ground-based observations of Kepler asteroseismic targets
K. Uytterhoeven, R. Szabo, J. Southworth +42
We present the ground-based activities within the different working groups of the Kepler Asteroseismic Science Consortium (KASC). The activities aim at the systematic characterizat…
Variable Stars
G. Handler, K. R. Pollard, M. S. Cunha +10
This is the triennial report of IAU Commission 27, mostly presenting a review of recent advances in the field.
The symphony of pulsations and binarity among massive stars using HERMES spectroscopy and TESS photometry
K. Thomson-Paressant, D. M. Bowman, F. Nardini +16
A wide range of variability mechanisms exist among intermediate mass and massive stars, which are not yet fully understood. Using complementary data sources for a large population…
On the Existence of "Maia variables"
F. Kahraman AliçavuÅ, G. Handler, S. Chowdhury +5
There are different classes of pulsating stars in the H-R diagram. While many of those classes are undisputed, some remain a mystery such as the objects historically called "Maia v…
Towards a seismic model of the Delta Scuti star XX Pyxidis
A. A. Pamyatnykh, W. A. Dziembowski, G. Handler +1
Frequencies of 13 oscillation modes in the star XX Pyxidis (CD-24 7599) are accurately measured but for none of the modes the spherical harmonic degree l is known. We present resul…
Pulsations and outbursts in Be stars: Small differences - big impacts
D. Baade, Th. Rivinius, A. Pigulski +12
New high-cadence observations with BRITE covering many months confirm that coupled pairs of nonradial pulsation modes are widespread among early-type Be stars. With the difference…
The roAp star Circini as seen by BRITE-Constellation
W. W. Weiss, H. -E. Fröhlich, A. Pigulski +25
We report on an analysis of high-precision, multi-colour photometric observations of the rapidly-oscillating Ap (roAp) star Cir. These observations were obtained with the BRIT…
Short-term variability and mass loss in Be stars I. BRITE satellite photometry of and Centauri
D. Baade, Th. Rivinius, A. Pigulski +13
Empirical evidence for the involvement of nonradial pulsations (NRP's) in the mass loss from Be stars ranges from (i) a singular case (\object{ Cen}) of repetitive mass ejectio…
Constraints of a pulsation frequency on stellar parameters in the eclipsing spectroscopic binary system: V577 Oph
O. L. Creevey, J. Telting, J. A. Blemonte +7
We present a preliminary spectroscopic analysis of the binary system V577Oph, observed during the summer of 2007 on the 2.6m NOT telescope on La Palma. We have obtained time series…
HD 42477: coupled r modes, g modes and a p mode in an A0Vnne star
D. W. Kurtz, R. Jayaraman, P. Sowicka +4
Several studies have shown that a number of stars pulsating in p modes lie between the Cep and Sct instability strips in the Hertzsprung-Russell (HR) Diagram. At present,…
An asteroseismic study of the Beta Cephei star Theta Ophiuchi: photometric results
G. Handler, R. R. Shobbrook, T. Mokgwetsi
We have carried out a three-site photometric campaign for the Beta Cephei star Theta Ophiuchi from April to August 2003. 245 hours of differential photoelectric uvy photometry were…
On the Period-Luminosity-Colour-Metallicity relation and the pulsational characteristics of lambda Bootis type stars
E. Paunzen, G. Handler, W. W. Weiss +7
The group of lambda Bootis type stars comprises late B- to early F-type, Population I objects which are basically metal weak, in particular the Fe group elements, but with the clea…
Massive pulsating stars observed by BRITE-Constellation. I. The triple system Beta Centauri (Agena)
A. Pigulski, H. Cugier, A. Popowicz +16
This paper aims to precisely determine the masses and detect pulsation modes in the two massive components of Beta Cen with BRITE-Constellation photometry. In addition, seismic mod…
TESS Cycle 2 observations of roAp stars with 2-min cadence data
D. L. Holdsworth, M. S. Cunha, M. Lares-Martiz +46
We present the results of a systematic search of the Transiting Exoplanet Survey Satellite (TESS) 2-min cadence data for new rapidly oscillating Ap (roAp) stars observed during the…
Asteroseismology of the Beta Cephei star Nu Eridani: Interpretation and applications of the oscillation spectrum
A. A. Pamyatnykh, G. Handler, W. A. Dziembowski
The oscillation spectrum of Nu Eri is the richest known for any variable of the Beta Cephei type. We interpret the spectrum in terms of normal mode excitation and construct seismic…
Tidally Trapped Pulsations in Binary Stars
J. Fuller, D. W. Kurtz, G. Handler +1
A new class of pulsating binary stars was recently discovered, whose pulsation amplitudes are strongly modulated with orbital phase. Stars in close binaries are tidally distorted,…
Abundance analysis of the Gamma Doradus - Delta Scuti hybrid metallic line (Am) star HD 8801
R. Neuteufel, W. Weiss, G. Handler
Low frequency oscillation, typical for Gamma Doradus g-mode type stellar core sensitive pulsation, as well as higher frequency Delta Scuti type pulsation typical for p-modes, sensi…
Asteroseismological studies of three Beta Cephei stars: IL Vel, V433 Car and KZ Mus
G. Handler, R. R. Shobbrook, F. F. Vuthela +3
We have acquired between 127 and 150 h of time-resolved multicolour photometry for each of the three Beta Cephei stars IL Vel, V433 Car and KZ Mus over a time span of four months f…
BRITE-Constellation: nanosatellites for precision photometry of bright stars
W. W. Weiss, S. M. Rucinski, A. F. J. Moffat +17
BRITE-Constellation (where BRITE stands for BRIght Target Explorer) is an international nanosatellite mission to monitor photometrically, in two colours, the brightness and tempera…
The Hvar survey for roAp stars: II. Final results (Research Note)
E. Paunzen, M. Netopil, M. Rode-Paunzen +2
The 60 known rapidly oscillating Ap (roAp) stars are excellent laboratories to test pulsation models in the presence of stellar magnetic fields. Our survey is dedicated to search f…
beta Cas: the first delta Scuti star with a dynamo magnetic field
K. Zwintz, C. Neiner, O. Kochukhov +10
F type stars are characterised by several physical processes such as different pulsation mechanisms, rotation, convection, diffusion, and magnetic fields. The rapidly rotating delt…
Asteroseismology of the Beta Cephei star Nu Eridani -- IV. The 2003-4 multisite photometric campaign and the combined 2002-4 data
M. Jerzykiewicz, G. Handler, R. R. Shobbrook +5
The second multisite photometric campaign devoted to Nu Eri is reported. For Nu Eri, analysis of the new data adds four independent frequencies to the nine derived previously from…
Search for sdB/WD pulsators in the Kepler FOV
R. Silvotti, G. Handler, S. Schuh +2
In this article we present the preliminary results of an observational search for subdwarf B and white dwarf pulsators in the Kepler field of view, performed using the DOLORES came…
Combining BRITE and ground-based photometry for the Beta Cephei star Nu Eridani: impact on photometric pulsation mode identification and detection of several g modes
G. Handler, M. Rybicka, A. Popowicz +12
We report a simultaneous ground and space-based photometric study of the Beta Cephei star Nu Eridani. Half a year of observations have been obtained by four of the five satellites…
The pulsating DA white dwarf star EC 14012-1446: results from four epochs of time-resolved photometry
G. Handler, E. Romero-Colmenero, J. L. Provencal +4
The pulsating DA white dwarfs are the coolest degenerate stars that undergo self-driven oscillations. Understanding their interior structure will help to understand the previous ev…
Photometric studies of three multiperiodic Beta Cephei stars: Beta CMa, 15 CMa and KZ Mus
R. R. Shobbrook, G. Handler, D. Lorenz +1
We have carried out single and multi-site photometry of the three Beta Cephei stars Beta and 15 CMa as well as KZ Mus. For the two stars in CMa, we obtained 270 h of measurement in…
Characterization of the Scuti eclipsing binary KIC 4851217 and its tertiary companion as well as detection of tidally tilted pulsations
Z. Jennings, J. Southworth, S. A. Rappaport +3
Stellar theory enables us to understand the properties of stars at different stages of their evolution, and contributes to other fields of astrophysics such as galactic and exoplan…
Photometric multi-site campaign on the open cluster NGC 884 I. Detection of the variable stars
S. Saesen, F. Carrier, A. Pigulski +62
CONTEXT: Recent progress in the seismic interpretation of field beta Cep stars has resulted in improvements of the physics in the stellar structure and evolution models of massive…
Multisite spectroscopic seismic study of the beta Cep star V2052 Oph: inhibition of mixing by its magnetic field
M. Briquet, C. Neiner, C. Aerts +29
We used extensive ground-based multisite and archival spectroscopy to derive observational constraints for a seismic modelling of the magnetic beta Cep star V2052 Ophiuchi. The lin…
The pulsation modes of the pre-white dwarf PG 1159-035
J. E. S. Costa, S. O. Kepler, D. E. Winget +74
PG 1159-035, a pre-white dwarf with T_eff=140,000 K, is the prototype of both two classes: the PG1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-0…
Triple system HD 201433 with a SPB star component seen by BRITE-Constellation: Pulsation, differential rotation, and angular momentum transfer
T. Kallinger, W. W. Weiss, P. G. Beck +17
Stellar rotation affects the transport of chemical elements and angular momentum and is therefore a key process during stellar evolution, which is still not fully understood. This…
Asteroseismology of hybrid pulsators made possible: simultaneous MOST space photometry and ground-based spectroscopy of Gamma Peg
G. Handler
We have acquired simultaneous high-precision space photometry and radial velocities of the bright hybrid Beta Cep/SPB pulsator Gamma Peg. Frequency analyses reveal the presence of…
Analysis of IUE spectra of helium-rich white dwarf stars
B. G. Castanheira, S. O. Kepler, G. Handler +1
We studied the class of DB white dwarf stars, using re-calibrated UV spectra for thirty four DBs obtained with the IUE satellite. By comparing the observed energy distributions wit…
The observation of Delta Sct and Gamma Dor stars by using MONS satellite
F. M. Zerbi, E. Poretti, C. Aerts +2
The MONS space experiment will be able to verify some of the most important topics in the asteroseismologic studies of Delta Sct and Gamma Dor stars. We discuss how the Doradu…
2006 Whole Earth Telescope Observations of GD358: A New Look at the Prototype DBV
J. L. Provencal, M. H. Montgomery, A. Kanaan +53
We report on the analysis of 436.1 hrs of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 200…