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E. Ragan,
M. Mikolajewski,
T. Tomov,
W. Dimitrow, M. Fagas,
T. Kwiatkowski,
A. Schwarzenberg-Czerny,
Ch. Buil,
E. Swierczynski,
T. Brozek, [......],
C. Galan,
A. Karska,
M. Klosinska,
M. Lewandowski,
T. Radomski,
P. Rozanski,
M. Wiecek,
P. Wychudzki,
A. Zajczyk,
M. Zielinska
[show abstract]
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ABSTRACT: We present photometric and spectral observation for four novae: V2362 Cyg, V2467 Cyg, V458 Vul, V2491 Cyg. All objects belongs to the "fast novae" class. For these stars we observed different departures from a typical behavior in the light curve and spectrum. Comment: 4 pages, 4 figures
04/2010;
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M. Ratajczak,
T. Kwiatkowski,
A. Schwarzenberg-Czerny,
W. Dimitrov,
M. Konacki,
K. G. Hełminiak,
P. Bartczak, M. Fagas,
K. Kamiński,
P. Kankiewicz,
W. Borczyk,
A. Rożek
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ABSTRACT: First spectroscopic and new photometric observations of the eclipsing binary FM Leo are presented. The main aims were to determine the orbital and stellar parameters of the two components and their evolutionary stage. First spectroscopic observations of the system were obtained with the David Dunlap Observatory and Poznań Spectroscopic Telescope spectrographs. The results of the orbital solution from radial velocity curves are combined with those derived from the light-curve analysis (V-band photometry from the All Sky Automated Survey and supplementary observations of eclipses with the 1 and 0.35 m telescopes) to derive orbital and stellar parameters. jktebop, Wilson–Devinney binary modelling codes and a two-dimensional cross-correlation method were applied for the analysis. We find the masses to be M1= 1.318 ± 0.007 and M2= 1.287 ± 0.007 M⊙ and the radii to be R1= 1.648 ± 0.043 and R2= 1.511 ± 0.049 R⊙ for primary and secondary stars, respectively. The evolutionary stage of the system is briefly discussed by comparing physical parameters with current stellar evolution models. We find that the components are located at the main sequence, with an age of about 3 Gyr.
Monthly Notices of the Royal Astronomical Society 02/2010; 402(4):2424 - 2428. · 4.90 Impact Factor
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R. Baranowski,
R. Smolec,
W. Dimitrov,
T. Kwiatkowski,
A. Schwarzenberg-Czerny,
P. Bartczak, M. Fagas,
W. Borczyk,
K. Kamiński,
P. Moskalik,
R. Ratajczak,
A. Rożek
[show abstract]
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ABSTRACT: ABSTRACTV440 Per is a Population I Cepheid with a period of 7.57 d and low-amplitude, almost sinusoidal light and radial velocity curves. With no reliable data on the first harmonic, its pulsation mode identification remained controversial. We obtained a radial velocity curve of V440 Per with our new high-precision and high-throughput Poznań Spectroscopic Telescope. Our data reach an accuracy of 130 m s−1 per individual measurement and yield a secure detection of the first harmonic with an amplitude of A2= 140 ± 15 m s−1. The velocity Fourier phase φ21 of V440 Per is inconsistent at the 7.25σ level with those of fundamental-mode Cepheids, implying that the star must be an overtone Cepheid, as originally proposed by Kienzle et al. Thus, V440 Per becomes the longest-period Cepheid with securely established overtone pulsations. We show that a convective non-linear pulsation hydrocode can reproduce the Fourier parameters of V440 Per very well. The requirement to match the observed properties of V440 Per constrains the free parameters of the dynamical convection model used in the pulsation calculations, in particular the radiative loss parameter.
Monthly Notices of the Royal Astronomical Society 07/2009; 396(4):2194 - 2200. · 4.90 Impact Factor
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[show abstract]
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ABSTRACT: Presented herein are preliminary radial velocity results for two
classical Cepheids: V440 Per and α UMi (Polaris). Both stars have
been observed with the Poznan Spectroscopic Telescope (PST), operational
since Aug 2007 at the Borowiec Station of Poznań Astronomical
Observatory in Poland. Data obtained for V440 Per suggest the presence
of a low-amplitude secondary mode of pulsations. Results of α UMi
observations confirm further pulsation amplitude growth, as observed
during the last decades.
Communications in Asteroseismology 02/2009; 159:48-50.
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[show abstract]
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ABSTRACT: Radial velocity curves obtained with the new Poznan Spectroscopic
Telescope (PST) are presented. PST is a small instrument located near
Pozná n, Poland, equipped with a fibre fed echelle spectrograph.
One of the first observed objects was γ Peg, a bright B2IV β
Cep type pulsator. It was found to have a period of P= 3.4h and an
amplitude of vrad variations of 3.5 km/s. Another star observed at PST,
28 And, is a member of the δ Sct family. For this object a
pulsational period of 1.66h could be determined.
Communications in Asteroseismology 11/2008; 157:361-362.
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A. Marciniak,
T. Michałowski,
M. Kaasalainen,
J. Ďurech,
M. Polińska,
T. Kwiatkowski,
A. Kryszczyńska,
R. Hirsch,
K. Kamiński, M. Fagas,
F. Colas,
S. Fauvaud,
G. Santacana,
R. Behrend,
R. Roy
[show abstract]
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ABSTRACT: We report photometric lightcurve observations of 184 Dejopeja (apparition years: 2000, 2002, 2005, 2006), 276 Adelheid (2000, 2001, 2004, 2005, 2006), and 556 Phyllis (1998, 2000, 2002, 2004, 2005, 2006) carried out on 48 nights at four observatories. Using all of the available lightcurves, the spin vectors, senses of rotation, and shape models of these three asteroids have been determined.
http://dx.doi.org/10.1051/0004-6361:20077694.
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J. Ďurech,
M. Kaasalainen,
A. Marciniak,
W. H. Allen,
R. Behrend,
C. Bembrick,
T. Bennett,
L. Bernasconi,
J. Berthier,
G. Bolt, [......],
R. Poncy,
D. Pray,
W. Pych,
R. Roy,
G. Santacana,
S. Slivan,
S. Sposetti,
R. Stephens,
B. Warner,
M Wolf
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ABSTRACT: Aims.We present physical models of ten asteroids obtained by means of lightcurve inversion. A substantial part of the photometric data was observed by amateur astronomers. We emphasize the importance of a coordinated network of observers that will be of extreme importance for future all-sky asteroid photometric surveys.Methods.The lightcurve inversion method was used to derive spin states and shape models of the asteroids.Results.We derived spin states and shape model for ten new asteroids: (110) Lydia, (125) Liberatrix, (130) Elektra, (165) Loreley, (196) Philomela, (218) Bianca, (306) Unitas, (423) Diotima, (776) Berbericia, and (944) Hidalgo. This increases the number of asteroid models up to nearly one hundred.
http://dx.doi.org/10.1051/0004-6361:20066347.
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A. Marciniak,
T. Michałowski,
R. Hirsch,
M. Polińska,
K. Kamiński,
T. Kwiatkowski,
A. Kryszczyńska,
R. Behrend,
L. Bernasconi,
J. Michałowski,
S. Starczewski, M. Fagas,
K. Sobkowiak
[show abstract]
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ABSTRACT: We present a set of new photometric observations of three main belt asteroids: 160 Una, 747 Winchester, and 849 Ara. This, combined with the available data, allowed us to construct their physical models. The lightcurve inversion method was used to obtain their spins and shapes. We have resolved problems with the rotation period of 160 Una, and found it to be $11.033176 \pm 0.000011$ h, almost twice the value given in the literature.
http://dx.doi.org/10.1051/0004-6361/200811078.
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A. Marciniak,
T. Michałowski,
M. Kaasalainen,
A. Kryszczyńska,
T. Kwiatkowski,
R. Hirsch,
K. Kamiński, M. Fagas,
M. Polińska,
F. P. Velichko,
M. J. Michałowski,
C. Snodgrass,
R. Behrend,
L. Bernasconi
[show abstract]
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ABSTRACT: We present photometric observations of three asteroids: 73 Klytia, 377 Campania, and 378 Holmia, together with their spin and shape models. The models were constructed with the lightcurve inversion method, using all available lightcurves of these objects. In the case of Campania, the long persisting doubts about its rotational period have been resolved. Various authors state periods between $8.48$ and $16$ h, while the period we determined is $11.664401 \pm 0.000010$ h.
http://dx.doi.org/10.1051/0004-6361:20078930.
