... SHTOL ' Special Astrophysical Observatory of the Russian AS, Nizhnij Arkhyz 357147, Russia The investigation of such a phenomenon as the magnetic field variability at long times (years - decennials) is very interesting. If the explanation of the magnetic field variability with rotation period by the oblique rotator model is evident, then the reason of the long-period variability is not clear yet, despite the existence of some assumptions on its nature. ... Fig.2. ... 213 Fig.3. ...

... 458 ­ 461 Magnetic Variability of the Ap Star HD 9996 Bychkov V. D.1 , Bychkova L. V.1 , Madej J.2 , Shatilov A. V.1 1 2 Special Astrophysical Observatory, Nizhny Arkhyz, Russia Warsaw University Observatory, Poland Abstract. ... Its phase magnetic curve exhibits two components. ... 1 Long­Perio d Magnetic Phase Curve Compilation of early photometric measurements of HD 9996 allowed us to constrain the corresponding period P in the range of 7750 < Pph < 8550 days (Pyper & Adelman, 1986). ...

We present the results of an extensive observing campaign on the O7.5 III star xi Persei. The UV observations were obtained with the International Ultraviolet Explorer. xi Per was monitored continuously in October 1994 during 10 days at ultraviolet and visual wavelengths. The ground-based optical observations include magnetic field measurements, HЮБ and He I lambda 6678 spectra, and were partially covered by photometry and polarimetry. ...

... The Search of a pulsar Once the dedispersed time series is obtained, a Fourier transformation is performed. ... 2 Binary parameters The orbit of a pulsar , as well as any object, in a binary system is determined in its geometrical characteristics, space displacement and syncronised in time by the following parameters : Semimajor axis Eccentricity Longitude of periastron Binary period Time of ascending node a e PB T0 True spin period and observed spin period The ...

... The accuracy of calculation of both INTERBALL spacecraft (SC) motion has been estimated at the IKI. ... The 30 days measuring intervals were used during the Tail probe (TP) orbital data treatment, and 15 days intervals - during the Auroral probe (AP) orbit determination. ... http://www.iki.rssi.ru/vprokhor/indap.htm for the Auroral probe; . http://www.iki.rssi.ru/vprokhor/indtp.htm for the Tail probe . ... http://www.iki.rssi.ru/vprokhor/ssc.htm , or http://www.iki.rssi.ru/vprokhor/amisan.htm . ...

... Several attempts to discover the FICN signal in VLBI nutation series made during last years failed. ... We investigated several VLBI CPO series by means of spectral and wavelet analysis. It has been shown that there are several periodic signals with close amplitude around the expected FICN period without any prevailing one that can be reliably associated with the FICN. ... DATA ANALYSIS We analyzed several CPO series obtained in IVS analysis centers by means of spectral and wavelet analysis. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... The top two plots show our new B data phased with our best fit period, superimposed on the polynomial fits of Manfroid Mathys (2000) to their larger B dataset (green dashed curve). In the top panel the second, slightly different, B curve (red dash-dotted line) is the variation of B predicted by our adopted field geometry. ... The bottom figure depicts the Bz field variations observed in HD 318107. ...

... The evolution equation presented above indicates that an accreting compact star must endeavor to attain an equilibrium state in which the resultant torque vanishes (Davidson and Ostriker, 1973[ 38 ]; Lipunov and Shakura, 1976[ 109 ]). ... Let us turn to the case of disk accretion. ... Since , the equilibrium period in the case of disk accretion is close to the critical period, , separating accretion stage A and the propeller stage P . ...

... 13, Moscow 119992, Russian Federation, e-mail: busarev@sai.msu.ru; 2 Research Institute Crimean Astrophysical Observatory, p/o Nauchnyi, Crimea 334413, Ukraine, e-mail: prok@crao.crimea.ua Summary: We propose a combined method of astronomical investigations of small or distant planets incorporating registration of a set of integral spectra of an object and their frequency analysis. ... An application of the method is shown on example of asteroid 21 Lutetia. ... 6] Busarev V. V. (2002), Solar Sys. ...

... Experimental base . ... The experimental base of the investigations is the topside sounding data obtained on board of the Intercosmos-19 and Cosmos-1809 satellites. ... It carried on board the following scientific payload: satellite ionospheric station for radio sounding of ionosphere (IS-338) and apparatus for the measurements of low-frequency electromagnetic field (VLF-2ME), electric component of high-frequency field (AHF-2K), electron temperature (KM-3), and spectrometer of photoelectrons (SF3-M)...

spaceweb@oulu.fi - last update: 13 September 1998, 1130 UT (RR) . Ground based magnetometer measurements are used to derive several indices that describe magnetic activity in the Earth 's environment. aa , AE , Ak(Hel) , Kp , Dst , PC , MT . ... AE index is an auroral electrojet index obtained from a number (usually greater than 10) of stations distributed in local time in the latitude region that is typical of the northern hemisphere auroral zone (Davis and Sugiura, 1966). ...