NEWTONsche Relativ-Mechanik

The NEWTONian mechanics involves the dynamical absoluteness of motions which means the presence of absolute accelerations in NEWTON's equations of motion. Against NEWTON's point of view HUYGENS (and LEIBNIZ and the young KANT and later MACH and POINCARÉ) have postulated that the dynamics of a closed system of n particles P_a is depending on relative kinematical quantities, only. These relative quantities have to be the differences of the absolute kinematical quantities of each particle P_a according to HUYGENS, KANT and POINCARÉ. — We prove that a closed system of N NEWTONian particles with the same atomic masses m (according to the hypothesis of HERTZ) can be described by a HUYGENsian relative dynamics in the rest system of the center of masses. In this reference system the HAMILTONian, the LAGRANGian, the virial, the angular momentum etc. of the N particle system are depending on the difference quantities, only. — However, the absolute dynamical meaning of motion in the NEWTONian mechanics leads to a paradoxon for this relativistic representation. This paradoxon is resulting by an ideal combination of two independing particle systems to one system in the mind. No such paradoxon is existing by a very modification of NEWTON's dynamics with respect to MACH's principle of the relativity of inertia.     

Radial velocity and light curves analysis of the eclipsing binary NN Vir

The eclipsing binary NN Vir is a short period system showing an EW‐type light curve. Photometric observations of NN Vir were done by Gomez‐Ferrellad & Garcia‐Melendo (1997) at Esteve Duran Observatory. We used photometric data of NN Vir for light curve analysis. The available spectroscopic data of NN Vir is new and we also used the first radial velocity data of this system obtained by Rusinski & Lu (1999) for analysis. The radial velocity and light curves analysis was made with the latest version ofWilson program(1998) and the geometric and physical elements of the system are derived. By searching the simultaneous solutions of the system, we have determined the masses and radii of the components : 1.89(M_⊙) and 1.65(R_⊙) for the primary component; 0.93(M_⊙) and 1.23(R_⊙) for the secondary component. We estimated effective temperatures of 7030(K) for the primary and 6977(K) for the secondary component. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Determining the orientation parameters of the ICRS/UCAC2 system using the Kharkov catalog of absolute stellar proper motions

The absolute proper motions of about 275 million stars from the Kharkov XPM catalog have been obtained by comparing their positions in the 2MASS and USNO-A2.0 catalogs with an epoch difference of about 45 yr for northern-hemisphere stars and about 17 yr for southern-hemisphere stars. The zero point of the system of absolute proper motions has been determined using 1.45 million galaxies. The equatorial components of the residual rotation vector of the ICRS/UCAC2 coordinate system relative to the system of extragalactic sources have been determined by comparing the XPM and UCAC2 stellar proper motions: ω _x,y,z = (−0.06, 0.17, −0.84) ± (0.15, 0.14, 0.14) mas yr⁻¹. These parameters have been calculated using about 1 million faintest UCAC2 stars with magnitudes R _UCAC2 > 16 ^m and J > 14 ^m . 7, for which the color and magnitude equation effects are negligible.     

Modeling the Eclipsing Binary System VW Cygni

Five color UBVRI photometric and polarimetric measurements of the eclipsing binary VW Cyg are reported. It is shown that in the primary minimum the luminosity is attenuated (at short wavelengths) even after passage of the second contact. This fact is interpreted as evidence of gaseous structures in the system. The exchange of matter among the system components is also confirmed by the O-C curve constructed from data covering nearly a hundred years. Polarimetric analysis makes it possible to isolate the intrinsic (P=0.030±0.02) and interstellar components of the polarization. The UBVRI light curves of VW Cyg have been resolved. This was done using an algorithm for synthesizing theoretical light curves in the Roche model. Good agreement was obtained between the theoretical curves and observations in the V, R, and I bands, but the observed minimum depths in the U and B bands exceed the theoretical values. This appears to be caused by gas flows in the system.     

V2213 Cyg is a New W Uma-Type System

V2213 Cyg was discovered as a variable star by Pavlenko (1999) in 1998. We present our photometry of V2213 Cyg from 1998–2003 based on CCD observations with the K-380 Cassegrain telescope of CrAO and the 60 cm Zeiss telescope of SAI. Observations have been carried out mostly in R and sometimes in B and V Johnson system. The total amount of data is 2270 points, covering ∼50 nights. We classify this binary as a W UMa-type contact system. Using all data we determined the orbital period to be 0.350079 ± 0.000007 day. The mean brightness varies between R = 14.35 and 14.05. The mean 1999–2003 orbital light curve has two humps and a primary minimum (I), which is 0.04 mag brighter than the deeper secondary one (II). The mean humps have slightly different height. The difference between two individual maxima varies within 0.1 mag, which may indicate an activity of the components. The highest hump is an asymmetrical one: it has sort of a shoulder at phases 0.75–0.80, before entering the less deep primary minimum (phase 0.0). The system is rather reddened, its colour indices are: B−V ∼ 0.8 and V−R ∼ 0.7, and give a spectral class of V2213 Cyg earlier than K.     

Control of chaos in the vicinity of the Earth‐Moon L5 Lagrangian point to keep a spacecraft in orbit

The concept of Space Manifold Dynamics is a new method of space research. We have applied it along with the basic idea of the method of Ott, Grebogi, and York (OGY method) to stabilize the motion of a spacecraft around the triangular Lagrange point L₅ of the Earth‐Moon system. We have determined the escape rate of the trajectories in the general three‐ and four‐body problem and estimated the average lifetime of the particles. Integrating the two models we mapped in detail the phase space around the L₅ point of the Earth‐Moon system. Using the phase space portrait our next goal was to apply a modified OGY method to keep a spacecraft close to the vicinity of L₅. We modified the equation of motions with the addition of a time dependent force to the motion of the spacecraft. In our orbit‐keeping procedure there are three free parameters: (i) the magnitude of the thrust, (ii) the start time, and (iii) the length of the control. Based on our numerical experiments we were able to determine possible values for these parameters and successfully apply a control phase to a spacecraft to keep it on orbit around L₅. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The very short period W UMa system V 1022 Ophiuchi

Photoelectric light curves of V1022 Oph inB andV are presented. It has been confirmed that it is a W UMa type eclipsing binary with one of the shortest periods known (P<0.^d25). Some general properties of the system have been derived.Based on observations made at the European Southern Observatory (La Silla/Chile)     

Photoelectric elements of the eclipsing binary XY Cep

The light curve andU, B andV observations of the system XY Cep have been presented. Photoelectric and absolute elements of the system have been determined. It is a semi-detached system.     

FZ Orionis: a short period W UMa system

PhotoelectricU , B andV observations of the eclipsing binary system FZ Orionis obtained by the author during three years 1984, 1985 and 1986 are presented and studied. The present photometry may settle the dispute regarding the class and the period of the system light variation between the GCVS 1969 ( Lyr;p = 1.597 d) and Figer (1983) and Le Brogneet al. (1984) (W UMa;p 0.4 d) in favour of the latter. A period change was detected which may be elucidated as due to the presence of a third body and mass exchange between the components. Times of ten minima were determined and new ephemeris have been deduced. The present light and colour curves were investigated and preliminary parameters for the system could be estimated.     

Photometric investigation of the evolved contact binary system DN Aur

We present here the photometric light curve analyses of the eclipsing binary star DN Aur. The CCD photometry, performed at the Behlen observatory using the 0.76 m automated telescope gave 646 individual data points inV andR bandpass filters. From this data we have determined a new epoch and an orbital period of 0.6168891 days. The published spectral classification is F3.The Wilson-Devinney model was used to derive the photometric solutions. DN Aur is a W UMa type contact binary system. The mass ratio, (q=m ₂/m ₁0.210, where star 2 is eclipsed at the primary minimum) suggests that the system has A-type configuration. The computed light curve has a third light of about 22 percent and a total eclipse in the secondary minimum. A solution with a cool spot on the secondary component is also found. We recommend spectroscopic study of DN Aur even though the light curve analysis show it to be a single line spectroscopic system. Generally contact systems of spectral type F3 have periods ranging from 0.25 to 0.5 days. The longer period of DN Aur suggests that it is an evolved contact system with case A mass transfer.     

HD 134 518: A Main-Sequence Detached or a Semi-detached Eclipsing Binary?

We have analyzed PRZYBYLSKY 's (1981) photometric observations of HD 134518, an eclipsing binary with a period of 1.15 days and a β Lyrae type light curve. Performing a grid of solutions with different assumed values of the mass ratio by means of the WILSON -DEVINNEY method we have determined the photometric elements of this variable, which shows an extremely low mass ratio (q = mc/mh = 0.06) and appears as semi-detached system. The discrepancies between the WILSON -DEVINNEY solution and the WOOD solution (GIURICIN et al. 1982) are pointed out. Die photometrischen Beobachtungen PRZYBYLSKYS (1981) von HD 134 518, einem Bedeckungsveränderlichen mit P = 1^d.15 und einer β-Lyrae-artigen Lichtkurve, wurden analysiert. Mittels der WILSON -DEVINNEY -Methode wurden für verschiedene Masseverhältnisse die photometrischen Elemente des Veränderlichen bestimmt, der ein extrem niedriges Massenverhältnis (q = mc/mh = 0.06) besitzt und halbgetrennt zu sein scheint.     

Fourier analysis of the light curves of eclipsing variables,XVI

The practical procedures for the solutions of the elements of any eclipsing system in the frequency-domain have been described in a previous paper of this series (Kopal and Demircan, 1978, Paper XIV). The fundamental quantities from which we depart in quest of our solution are twog-functions defining by the momentsA _2m (see Equations (2.13)–(2.16) in Paper XIV, or Equations (3.2)–(3.6) in Paper XV: Demircan, 1978b). If we establish the observational values for these functions, they constitute two independent relations between the unknown parametersa andc _o, and can be numerically solved for them with the aid of the general expressions for the respective moments. However, the determinacy of these parameters depends on not only the accuracy of observations but also the employedg-functions. For better understanding of the geometrical determinacy of the eclipse parametersa andc _o, different combinations of the momentsA _2m have been worked out asg-functions. For the index 2m, the values between 0 and 6 were applied. It has been noted that the behaviour of these functions vary but very little with applied different combinations of the moments. A choice of the most convenient moments to obtain a good determinacy for the eclipse elements were discussed. In this connection, (i) them-dependence of the moments, and the errors in their observational values have been considered, (ii) different practical procedures for the solution of eclipse elements were introduced, and (iii) different type of moments were tested.     

Photometric Properties of Clusters of Galaxies

We present CCD photometry of 16 Abell clusters and one cluster candidate found in POSS-II field 861. The images were taken at the 0.9 m Telescope at Cerro Tololo, in the g, r and i filters of the Gunn–Thuan system. We tested the idea proposed by Garilli et al. (1996) that there is a population of unusually red galaxies which could be associated with either the field or clusters. Garilli et al. (1996) suggest that these galaxies have anomalously red colours, but we find that these objects are all near the limiting magnitude of the images (20^m<r<22^m) and have colours that are consistent with those expected for stars or field galaxies at z∼0.7. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cyclic light and period variations of the UV Leonis system

Solutions of the new standard V‐light curves for the EA type binary UV Leo are obtained using the PHOEBE code (0.31a version). Absolute parameters of the stellar components were then determined, enabling them to be positioned on the absolute magnitude‐color (l.e. M_V vs. B – V) isochrones diagram, based on which the age of the system is estimated to be >4×10⁹ yr. Also times of minima data (“O – C curve”) have been analyzed. Apart from an almost sinusoidal variation with a period of 29.63 yr, which modulates the orbital period, and was attributed to a third body orbiting around the system, other cyclic variation in the orbital period and also brightness, with time scales of 24.25 and 22.77 yr were found, respectively. We associate this with a magnetic activity cycle newly reported here for UV Leo (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

First ground‐based photometry and light‐curve analysis of the eccentric eclipsing binary V744 Cas

The first ground‐based BVR photometric observations of the recently discovered eclipsing binary V744 Cas are presented. From these measurements, timings for two primary and one secondary minima have been calculated. The light curves of the system were analyzed by using the Wilson‐Devinney program. The analysis shows that the system is detached with two similar components of spectral type A2V, and the orbit is eccentric (e = 0.0662 ± 0.0005). The longitude of the periastron (ω) was found significantly different for two different light curves (ours and that of Hipparcos), which is strongly suggestive of an apsidal motion with a period of about 425 ± 68 yr. This makes V744 Cas an important candidate for studies of apsidal motions. The first estimate of the absolute dimensions place the system close to the terminal age of the main sequence (TAMS) in the HR diagram. The distance from the spectroscopic parallax (d = 740 ± 10 pc) was found to be slightly larger than the Hipparcos distance of d = 610 ± 400 pc. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

On a Property of Gravitational Systems

If one attributes to each component i of a gravitational system a dimensionless parameter ψ _i equal to the ratio of its relative mass (with respect to the mass of the system) to its relative position (with respect to a generally defined radius) and sums up the ψ _i values of all components outside the central core, one obtains a mass distribution index Σψ of the order of unity irrespective of the size or the type of the system. In the case of spiral galaxies (and probable other galactic systems) this property applies not only to the whole galaxy, but also to the matter inside any radius larger than the core radius. The mass distribution index in these systems has a maximum Σψ_* at a certain radius r _*, which strongly correlates with the surface brightness at r _* in galaxies with similar mass to light ratio. The gravitational acceleration of all galaxies at r _* divided by (Σψ_*)² is constant and approximately equal to MOND acceleration parameter. Also, at this radius all galaxies have a surface temperature of the order of the temperature of the cosmic microwave background radiation. This revised version was published online in July 2006 with corrections to the Cover Date.     

Stars outside the Hipparcos list closely encountering the Solar system

Based on currently available kinematic data, we have searched for stars outside the Hipparcos list that either closely encountered in the past or will encounter in the future the Solar system within several parsecs. For the first time, we have identified two single stars, GJ 3379 (G 099-049) and GJ 3323 (LHS 1723), as candidate for a close encounter with the solar orbit. The star GJ 3379 could encounter the Sunmore closely to aminimumdistance d _min = 1.32±0.03 pc at time t _min = −163 ± 3 thousand years. We have found two potential candidates for a close encounter that have only photometrical distances: the white dwarf SSSPM J1549-3544 without any data on its radial velocity and the L-dwarf SDSS J1416+1348. The probabilities of their penetration into the Oort cloud region are 0.09 (at a model radial velocity <V _r < = 50 km s⁻¹) and 0.05, respectively.     

Updated UBV Light-Curve and Period Analysis of Eclipsing Binary HS Herculis

UBV light-curves of the eclipsing binary HS Herculis, obtained in 2002–2003 observational seasons, were analysed with Wilson-Devinney computer code. New absolute dimensions of the system were calculated using the results of the light-curve analysis. Period variation of the system was also investigated. Several new times of minima have been secured for this problematic system. An apsidal motion with a period of 80.7 years was confirmed and a third body in a pretty eccentric orbit (e ₃ = 0.90 ± 0.08) with a period of 85.4 years was found. The corresponding internal structure constants of the binary system, log k ₂, and the mass of the third body were derived.     

Cyclic variations of the period and luminosity of SV Camelopardalis

New standardized V ‐band light curves (LCs) for the eclipsing binary SV Cam have been modeled using the PHOEBE program (v. 0.31a). Absolute parameters of the stellar components were then determined, enabling them to be positioned on the mass‐radius diagram. Analysis of eclipse minima timing data (O – C diagrams) indicated two cyclic periods of 48.0 and 23.3 yr. These cyclic variations of the orbital period are interpreted in terms of motion of a third body around the system and magnetic activity cycle modulating the orbital period of SV Cam via the Applegate (1992) mechanism. The use of the Applegate model for SV Cam has been checked by examining the long term brightness variation and calculating some important parameters of this system. The results of these calculations favor the modulation of the orbital period by the Applegate mechanism. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Identification of SrF molecular lines in the spectrum of sunspot umbra

A high resolution spectrum of a sunspot umbra is used for identification of rotational lines due to (0, 0) band of the A ²Π–X ²Σ⁺ system and (0, 0), (1, 1), and (2, 2) bands of the B ²Σ⁺–X ²Σ⁺ system of the molecule SrF. The published sunspot umbral spectrum obtained with Fourier Transform Spectrometer and solar telescope of National Solar Observatory/National Optical Astronomy Observatory at Kitt Peak was used for the study. The new identification of more than 200 SrF lines in the umbral spectrum confirms that this molecule accounts for the majority of lines in the spectral range 15050 to 15360 cm⁻¹ and 17240 to 17300 cm⁻¹. Equivalent widths have been measured for well-resolved lines of these bands and the effective rotational temperatures have been estimated for which the presence is confirmed.