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Context.Basaltic V-type asteroids play a crucial role in studies of Solar System evolution and planetesimal formation. Comprehensive studies of their physical, dynamical, and statistical properties provide insight into these processes. Thanks to wide surveys, currently there are numerous known V-type and putative V-type asteroids, allowing a detailed statistical analysis.Aims.Our main goal is to analyze I corrected for US language conventions in this paper the currently available large sample of V-type spin rates, to find signatures of the non-gravitational Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect among the different V-type populations, and to estimate the spin barrier and critical density for V-type asteroids. Our intention is to increase the pool of information about the intriguing V-types.Methods.We collected rotational periods from the literature for spectrally confirmed V-types, putative V-types, and Vesta family members. Through spectroscopic observations we confirmed their taxonomic type and verified the high confirmation rates of the putative V-types. We combined the collected periods with periods estimated in this manuscript and produced rotational frequency distributions. We determined the spin barrier in the frequency–light curve amplitude space for V-type asteroids.Results.We analyzed rotational periods of 536 asteroids in our sample. As expected, due to the small size of the objects analyzed, the frequency distributions for the Vesta family and the V-types outside the family are inconsistent with a Maxwellian shape. The Vesta family shows an excess of slow-rotators. V-types outside the family show an excess of both slow and fast rotators. Interestingly, we found that the population of V-types outside the Vesta family shows a significant excess of fast rotators compared to the Vesta family. The estimated critical density for V-type asteroids exceedsρc= 2.0 g cm−3, which surpasses the previous estimates.Conclusions.We demonstrated that V-type asteroids have been influenced by the thermal radiation YORP effect and that their critical spin rate is higher than for C-type asteroids. The population of V-types outside the Vesta family shows a significant excess of fast rotators compared to the Vesta family. We hypothesize that the objects that evolved from the Vesta family though the Yarkovsky drift are also more susceptible to the YORP effect. Objects for which YORP has not yet had enough time to act and those that are more YORP resistant will be left in the family, which explains the relatively small proportion of fast rotators being left. The YORP timescale must thus be similar to the migration timescale for those objects.

First spectroscopic and new photometric observations of the eclipsing binary FM Leo are presented. The main aims were to determine orbital and stellar parameters of two components and their evolutionary stage. First spectroscopic observations of the system were obtained with DDO and PST spectrographs. The results of the orbital solution from radial velocity curves are combined with those derived from the light-curve analysis (ASAS-3 photometry and supplementary observations of eclipses with 1 m and 0.35 m telescopes) to derive orbital and stellar parameters. JKTEBOP, Wilson-Devinney binary modelling codes and a two-dimensional cross-correlation (TODCOR) method were applied for the analysis. We find the masses to be M_1 = 1.318 $\pm$ 0.007 and M_2 = 1.287 $\pm$ 0.007 M_sun, the radii to be R_1 = 1.648 $\pm$ 0.043 and R_2 = 1.511 $\pm$ 0.049 R_sun 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 the components are located at the main sequence, with an age of about 3 Gyr., 5 pages, 4 figures, to appear in MNRAS

V440 Per is a Population I Cepheid with the period of 7.57 day and low amplitude, almost sinusoidal light and radial velocity curves. With no reliable data on the 1st harmonic, its pulsation mode identification remained controversial. We obtained a radial velocity curve of V440 Per with our new high precision and high throughput Poznan Spectroscopic Telescope. Our data reach the accuracy of 130 m/s per individual measurement and yield a secure detection of the 1st harmonic with the amplitude of A_2= 140+/- 15 m/s. The velocity Fourier phase \phi_21 of V440 Per is inconsistent at the 7.25 \sigma level with those of the fundamental mode Cepheids, implying that the star must be an overtone Cepheid, as originally proposed by Kienzle et al.(1999). Thus, V440 Per becomes the longest period Cepheid with the securely established overtone pulsations. We show, that the convective nonlinear pulsation hydrocode can reproduce the Fourier parameters of V440 Per very well. Requirement to match the observed properties of V440 Per constrains free parameters of the dynamical convection model used in the pulsation calculations, in particular the radiative losses parameter., Comment: Submitted to MNRAS

The paper confronts chaos indicators of two basic types: spectral methods and variational methods. The spectral methods include the spectral numbers and the integrated autocorrelation function. Variational methods discussed are FLI, MEGNO and OFLI2. Using an ad hoc model of coupled pendulum we demonstrate various spurious patterns that appear in the maps of the chaos indicators. Spectral methods generate spurious Moire fringes, whereas variational methods are sensitive to the integration time or – in the case of the first-order variations indicators – to the initial direction of the variations vector. An example of major discrepancy between the two kinds of methods is given for an unstable periodic orbit. The influence of the initial variations vector is explained in the context of Lyapunov vectors theory and some selection rules are recommended.

We describe numerical tools for the stability analysis of extrasolar planetary systems. In particular, we consider the relative Poincare variables and symplectic integration of the equations of motion. We apply the tangent map to derive a numerically efficient algorithm of the fast indicator MEGNO (a measure of the maximal Lyapunov exponent) that helps to distinguish chaotic and regular configurations. The results concerning the three-planet extrasolar system HD 37124 are presented and discussed. The best fit solutions found in earlier works are studied more closely. The system involves Jovian planets with similar masses. The orbits have moderate eccentricities, nevertheless the best fit solutions are found in dynamically active region of the phase space. The long term stability of the system is determined by a net of low-order two-body and three-body mean motion resonances. In particular, the three-body resonances may induce strong chaos that leads to self-destruction of the system after Myrs of apparently stable and bounded evolution. In such a case, numerically efficient dynamical maps are useful to resolve the fine structure of the phase space and to identify the sources of unstable behavior.

We have computed the integrated autocorrelation function for different families of geosynchronous, inclined orbits in order to detect the regions of chaotic motion. In order to reduce the problems due to high eccentricity orbits, the logarithmic Hamiltonian regularization was applied and a symplectic integrator of the Wisdom–Holman type was implemented. The orbits were integrated for an interval of 10,000 days. The results indicate that non-predictable orbits can be found in this relatively short time in the separatrix zone of the 1:1 tesseral resonance. Their chaotic nature results from the interchange between libration and circulation type of motion, and from the significant eccentricity growth, caused by the Kozai–Lidov resonance. Some of these orbits intersects the Earth’s surface in time shorter than 20 years for a particular initial geometry of interacting bodies.

We present the results of a campaign of simultaneous observations of V603 Aql in the X-ray and UV bands ac- complished with the IUE and ROSAT satellites. Simultaneous observations cover 20 orbital cycles, while the total span of all the observations is 40 cycles. This constitutes the longest continuous UV time series of simultaneous space observations of a cataclysmic variable. As all high energy radiation is ultimately powered by accretion, it is perhaps remarkable that we observe some signs of correlations of the UV line and continuum emission with the X-ray flux at zero lag, but none over a range of time lags from 400 40 000 s. A hint of some lagged correlation was revealed for UV color and X-ray flux. We detect a very strong modulation of intensity of the UV lines of CIV and SiIV. The modulation appears coherent over the range of observation and its period of 0:1380(5) d is consistent with the spectroscopic orbital period but diers significantly from the period of photometric modulation. Furthermore, we observe variable P-Cygni profiles of the CIV1550 line. Its absorption and emission components are modulated with the orbital period of the binary. These data present evidence for sustained asymmetry of the supersonic wind excited from the accretion disc yet pose diculties for the current disc and wind models. Since no periodic modulation was found in the X-ray band nor in the UV continuum, the present data do not lend support to our earlier classification of V603 Aql as an intermediate polar.

We present spectroscopic and photometric analysis of the quintuple star HD 86222 with an eclipsing component. Until now three visual components A, B, and C of this multiple star were known. Four components in the A/B pair were detected during the examination of the cross correlation functions obtained from the spectra. We noticed that the visual components A and B, separated by , are in fact two binary stars – one eclipsing pair and one spectroscopic system. The pair with higher radial velocity amplitude corresponds to the eclipsing period. Photometric and spectroscopic observations of the eclipsing binary enable us to obtain the Wilson-Devinney model. The masses of this pair are M1 = 1.29 ± 0.09 M⊙ and M2 = 1.33 ± 0.09 M⊙, respectively. The radii, slightly higher than for the main sequence stars, are R1 = 1.35 ± 0.01 R⊙ and R2 = 1.36 ± 0.01 R⊙, respectively. The main parameters of the spectroscopic binary are also estimated, but they must be confirmed by future observations because of the uncertainty of the period. The farthest star named C, is 15 arc seconds from the main A and B components. Assuming that this object is gravitationally connected with the A and B binary pairs, HD 86222 has at least five components.

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 Poznan 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. Individual Objects: V440Per, Polaris Introduction Both V440 Per and α UMi spectroscopy has been obtained with the old PST configuration. The telescope was equipped with two 0.4m parabolic mirrors (only one of them was operational during the period of observations). PST is currently being adjusted to simultaneously use both mirrors, which have been replaced with 0.5m ones in August 2008. PST is equipped with a mid-resolution (R = 35000) fibre-fed echelle spectrograph, based on the MUSICOS construction design (Baudrand & Bohm 1992). It covers the spectral range between 4500 and 9200 A. Image acquisition was performed with a high-quality low-noise 2k× 2k ANDOR CCD, at a temperature of −90◦ C. Data reduction and radial velocity measurements were done using the IRAF package (http://iraf.noao.edu/), as well as with combined Python and cl scripts developed by our team members. The cross-correlation method was used to obtain radial velocities. Further periodicity analysis was conducted using the Period04 (Lenz & Breger 2005) and TATRY (Schwarzenberg-Czerny 1996) software. V440 Per V440 Per is a bright (6.3 mag) star of F7 Ib spectral type. It is an overtone pulsator, with an oscillation period of 7.570 d (Luck et al. 2008). 158 spectra for this star have been obtained with PST between August 2007 and July 2008. Typical exposure times were 600 − 900 s, with a signal-to-noise ratio (S/N) varying from ∼ 20− 40, depending on weather conditions. Radial velocity data are presented in Fig. 1. Preliminary radial velocity measurements revealed a low-amplitude (∼ 90 m/s) second harmonic of V440 Per pulsations. If confirmed, that would make V440 Per the overtone M.Fagas, R. Baranowski, P.Bartczak, W.Borczyk, W.Dimitrow, et al. 49 0 0,5 1 1,5 2 phase -3 -2 -1 0 1 2 3 4 re la tiv e V _r ad [ km /s ] V440 Per PST, 14 Aug 2007 03 Jul 2008, P = 7.57 d, HJD0 = 2454325.202 Figure 1: Radial velocity curve of V440 Per obtained with PST. Cepheid with the longest pulsation period known. Data analysis is being carried out in cooperation with Pawel Moskalik. α UMi (Polaris) Spectroscopic and photometric observations of this bright classical Cepheid over the last century revealed changes in both pulsation period and amplitude. While the period was increasing, the amplitude (both photometric and spectroscopic) seemed to decrease, leading to the conclusion that Polaris’ pulsations might eventually cease. This trend, however, diverted during the last decades (Lee et al. 2008). PST’s design allows easy observations of Polaris. 330 spectra have been taken over seven months (Dec 2007 Jul 2008) with a typical exposure time of 150 s. The S/N in the obtained spectra was ∼ 30− 70, depending on weather conditions. 190 α UMi spectra (Dec 2007 Apr 2008) have been reduced so far. The influence of Polaris’ orbital motion on the star’s pulsation period has not been taken into account, as the analyzed data set only covers 4 months (∼ 1% of the orbital period). Preliminary analysis of the radial velocity data revealed a pulsation period slightly longer than expected (3.978 ± 0.002 d). The 2K amplitude found was 2.52 ± 0.03 km/s, which is consistent with recent work by Lee et al. (2008) and Spreckley & Stevens (2008). The star is scheduled for further observations with PST in the upcoming years. Acknowledgments. The authors acknowledge support from the Polish MNiI/MNiSzW Grant 1 P03D 025 29. 50 Preliminary results of V440 Per and α UMi observations with the Poznan Spectroscopic Telescope

The larger number of models of asteroid shapes and their rotational states derived by the lightcurve inversion give us better insight into both the nature of individual objects and the whole asteroid population. With a larger statistical sample we can study the physical properties of asteroid populations, such as main-belt asteroids or individual asteroid families, in more detail. Shape models can also be used in combination with other types of observational data (IR, adaptive optics images, stellar occultations), e.g., to determine sizes and thermal properties. We use all available photometric data of asteroids to derive their physical models by the lightcurve inversion method and compare the observed pole latitude distributions of all asteroids with known convex shape models with the simulated pole latitude distributions. We used classical dense photometric lightcurves from several sources and sparse-in-time photometry from the U.S. Naval Observatory in Flagstaff, Catalina Sky Survey, and La Palma surveys (IAU codes 689, 703, 950) in the lightcurve inversion method to determine asteroid convex models and their rotational states. We also extended a simple dynamical model for the spin evolution of asteroids used in our previous paper. We present 119 new asteroid models derived from combined dense and sparse-in-time photometry. We discuss the reliability of asteroid shape models derived only from Catalina Sky Survey data (IAU code 703) and present 20 such models. By using different values for a scaling parameter cYORP (corresponds to the magnitude of the YORP momentum) in the dynamical model for the spin evolution and by comparing synthetics and observed pole-latitude distributions, we were able to constrain the typical values of the cYORP parameter as between 0.05 and 0.6., Accepted for publication in A&A, January 15, 2013

Context. The shapes and spin states of asteroids observed with photometric techniques can be reconstructed using the lightcurve inversion method. The resultant models can then be confirmed or exploited further by other techniques, such as adaptive optics, radar, thermal infrared, stellar occultations, or space probe imaging.Aims. During our ongoing work to increase the set of asteroids with known spin and shape parameters, there appeared a need for displaying the model plane-of-sky orientations for specific epochs to compare models from different techniques. It would also be instructive to be able to track how the complex lightcurves are produced by various asteroid shapes.Methods. Basing our analysis on an extensive photometric observational dataset, we obtained eight asteroid models with the convex lightcurve inversion method. To enable comparison of the photometric models with those from other observing/modelling techniques, we created an on-line service where we allow the inversion models to be orientated interactively.Results. Our sample of objects is quite representative, containing both relatively fast and slow rotators with highly and lowly inclined spin axes. With this work, we increase the sample of asteroid spin and shape models based on disk-integrated photometry to over 200. Three of the shape models obtained here are confirmed by the stellar occultation data; this also allowed independent determinations of their sizes to be made.Conclusions. The ISAM service can be widely exploited for past and future asteroid observations with various, complementary techniques and for asteroid dimension determination.

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 six g modes of high radial order together with eight low-order Beta Cep oscillations in both data sets. Mode identification shows that all pulsations have spherical degrees l = 0 - 2. An 8.5 solar mass model reproduces the observed pulsation frequencies; all theoretically predicted modes are detected. We suggest, contrary to previous authors, that Gamma Peg is a single star; the claimed orbital variations are due to g-mode pulsation. Gamma Peg is the first hybrid pulsator for which a sufficiently large number of high-order g modes and low order p and mixed modes have been detected and identified to be usable for in-depth seismic modeling., Comment: 18 pages (4 pages in journal style), 4 figures, accepted for ApJ Letters

International audience; Two fast and reliable numerical integrators for the motion of the Oort Cloud comets in the Galactic tidal potential are presented. Both integrators are constructed as Hamiltonian splitting methods. The first integrator is based upon the canonical Hamiltonian equations split into the Keplerian part and a time-dependent perturbation. The system is regularized by the application of the Kuustanheimo-Stiefel variables. The composition rule of Laskar and Robutel with a symplectic corrector is applied. The second integrator is based on the approximate, averaged Hamiltonian. Non-canonical Lie-Poisson bracket is applied allowing the use of non-singular vectorial elements. Both methods prove superior when compared to their previously published counterparts.

International audience; Aims:We observed a near-Earth asteroid 2004 RZ164 to study its rotational properties. The object was chosen because of its small diameter of about 700 m, which is close to the 150 m threshold, separating monolithic and rubble-pile asteroids. Methods: With small telescopes at five observatories, equipped with CCD cameras, we obtained seven lightcurves, which were taken through the clear, R, and I filters. Results: Despite significant changes in the observing geometries (and large phase angles during observations), the peak-to-peak amplitudes of the lightcurves never exceeded 0.15 m, suggesting the almost spheroidal shape of this asteroid. There is a signature of a probable occultation/eclipse event in one of the lightcurves, which suggests 2004 RZ164 is a binary asteroid. Its primary component spins with a period of P=2.5559 h ± 0.0001 h and the orbital period of the system is longer than 10.8 h.

[Aims]: Our goal is to characterize AGN populations by comparing their X-ray and optical classifications within the framework of the standard orientation-based unified scheme. [Methods]: We present a sample of 99 spectroscopically identified (R ≤ 22 mag) X-ray selected point sources in the XMM-LSS survey which are significantly detected (≥3σ) in the [2-10] keV band with fluxes between 8 × 10-15 and 8 × 10 -14 erg s-1 cm-2, and which have more than 80 counts. We have compared their X-ray and optical classifications. To this end, we performed an X-ray spectral analysis for all of these 99 X-ray sources in order to assess whether they are intrinsically absorbed or not. The X-ray classification is based on the measured intrinsic column density. The optical classification is based on the measured FWHM of the permitted emission lines, the absence of broad lines being due to obscuration within the framework of the standard AGN unified scheme. [Results]: Introducing the fourfold point correlation coefficient r, we find a mild correlation between the X-ray and the optical classifications (r = 0.28), as up to 32 X-ray sources out of 99 have differing X-ray and optical classifications: on one hand, 10% of the type 1 sources (7/32) present broad emission lines in their optical spectra and strong absorption (NH int ≥ 1022 cm-2) in the X-rays. These objects are highly luminous AGN lying at high redshift and thus dilution effects by the host galaxy light are totally ruled out, their discrepant nature being an intrinsic property instead. Their X-ray luminosities and redshifts distributions are consistent with those of the unabsorbed X-ray sources with broad emission lines (L2-10 ∼ 4 × 10 44 erg s-1; z ∼ 1.9). On the other hand, 25/32 are moderate luminosity (L2-10 ≤ 5 × 1043 erg s -1) AGN, which are both unabsorbed in the X-rays and only present narrow emission lines in their optical spectra. Based on their line ratios in the optical, the majority of them have an optical spectrum which is more representative of the host galaxy rather than of a reddened AGN. We finally infer that dilution of the AGN by the host galaxy seems to account for their nature. 5/25 have been defined as Seyfert 2 based on their optical spectra. In conclusion, most of these 32 discrepant cases can be accounted for by the standard AGN unified scheme, as its predictions are not met for only 12% of the 99 X-ray sources., OG, EG, PGS, VB, and JS acknowledge support from the ESA PRODEX Programme “XMM-LSS”, and from the Belgian Federal Science Policy Office for their support. LC, DM, MT acknowledge financial contribution from contract ASI-INAF I/023/05/0. PG is a Fellow of the Japan Society for the Promotion of Science. MK acknowledges the German DLR under grant 50OR0404. ACR, JEC and FJC acknowledge financial support from the Spanish Ministry for Education and Science, under projects ESP2003-00812 and ESP2006-13608-C02-01. JAT, SM, SR and MW acknowledge support from the UK PPARC research council.

We present the new, second spectroscopic telescope of Poznań Astronomical Observatory. The telescope allows automatic simultaneous spectroscopic and photometric observations and is scheduled to begin operation from Arizona in autumn 2013. Together with the telescope located in Borowiec, Poland, it will constitute a perfect instrument for nearly continuous spectroscopic observations of variable stars. With both instruments operational, the Global Astrophysical Telescope System will be established.

The Global Astronomical Telescope System is a project managed by the Astronomical Observatory Institute of Adam Mickiewicz University in Poznań (Poland) and it is primarily intended for stellar medium/high resolution spectroscopy. The system will be operating as a global network of robotic telescopes. The GATS consists of two telescopes: PST 1 in Poland (near Poznań) and PST 2 in the USA (Arizona). The GATS project is also intended to cooperate with the BRITE satellites and supplement their photometry with spectroscopic observations.

International audience; Lightcurves of the asteroid 1572 Posnania were obtained at six observatories on 19 nights during four apparitions: in 1993, 1994-95, 1996, and 1999. The synodical period is found to be 8.048 hours and the observed amplitudes of brightness variations are in the range of 0.37-0.40 mag. The sense of rotation is retrograde with a sidereal period Psid = 0.3353931 /- 0.0000003 days. The ecliptic coordinates of the pole of this asteroid are lambdap = 46deg /- 6deg and betap = -65deg /- 5deg. The shape of Posnania can be approximated by a triaxial ellipsoid model with semiaxes ratios a/b = 1.35 /- 0.01 and b/c = 1.04 /- 0.03. Partly based on observations collected at the European Southern Observatory, La Silla, Chile.

Context. Recent studies have uncovered evidence that the statistical properties of asteroids’ physical parameters are a fundamental source of information on the physics of their collisions and evolution. The analysis of the spin rates and spin vector distributions helps us to understand the role of various known and new effects. The alignment of spin vectors and the correlation of spin rates are for the first time observed for ten members of the Koronis family. These unexpected non-random orientations of the spin axes and correlations of the spin rates, now known as Slivan states are interpreted in terms of a YORP effect and spin-orbit resonances. Aims. To study non-gravitational-effects, there appears to be a need for new observational campaigns devoted to determining the physical parameters of the asteroid families. Methods. We analysed the photometric observations of the asteroids, which are the most efficient method of studying asteroid physical parameters.Results. We report the results of a ten-year long observational survey of the light variations of objects in the Flora region. We present 544 individual lightcurves of 55 objects obtained at various observing geometries. These lightcurves yield new or refined synodic periods for 32 asteroids and confirm period determinations for 23 objects in our sample. To improve the statistics of the Flora family objects, we add to our dataset 91 objects with reliably determined periods. The distribution of rotation rates for the Flora family is non-Maxwellian at a confidence level of 94% and different from those of the Koronis and the Hungaria families. It seems to be consistent with the long-term influence of the YORP effect, although it is also indicative of a younger age for the Flora family compared to both the Koronis and the Hungaria families. Conclusions. Our new data is a foundation for the spin vector and shape determinations that will be the objectives of the second paper of the series. We search for spin vector and spin periods correlations in order to determine whether Slivan states exist in the Flora family.

Radiation-induced torques on ellipsoids of revolution are discussed. Exact formulae for the thermal YORP torques are given in terms of elliptic integrals. It is demonstrated that in the absence of thermal inertia, the average values of dynamically significant projections of these torques are zero if a spheroid rotates around the axis of maximum inertia and if there are no resonances between rotation and orbital motion. The thermal lag leads to a systematic drift in the obliquity, but it does not affect the rotation period. The direct radiation pressure torques on spheroids are shown to be zero.

In 1995 asteroid 6489 Golevka (1991 JX) had a close encounter with the Earth at a distance of 0.034 AU, providing a good opportunity for a detailed study of a small Solar System object. In this paper we report the results of an extensive international obs