In this article mathematical and computer models of sun sensor and magnetic sensor are considered that can be used for determination of small satellite attitude. In particular, the mathematical models of slit sun sensor and flux-gate magnetic sensor are given.

The concept that open magnetic flux of the Sun (rooted with one and only one footpoint at the Sun) is a conserved quantity is taking root in the heliospheric community. Observations show that the Sun’s open magnetic flux returns to the baseline from one solar minimum to the next. The temporary enhancement in the 1 AU heliospheric magnetic flux near solar maximum can be accounted for by the temp...

An observational relationship has been well established among magnetic reconnection, high-energy flare emissions and the rising motion of erupting flux ropes. In this paper, we verify that the rate of magnetic reconnection in the low corona is temporally correlated with the evolution of flare nonthermal emissions in hard X-rays and microwaves, all reaching their peak values during the rising ph...

The Sun’s magnetic activity has steadily declined during its main-sequence life. While the solar photospheric luminosity was about 30% lower 4.6Gyr ago when the Sun arrived on the main sequence compared to present-day levels, its faster rotation generated enhanced magnetic activity; magnetic heating processes in the chromosphere, the transition region, and the corona induced ultraviolet, extrem...

Observations suggest that magnetic fields at the solar photosphere may be structured below the limit of the present resolution. We argue that numerical simulations could be used in a complementary way to observations in order to study the small-scale structure of photospheric fields. We present a number of illustrative examples. Subject headings: convection — MHD — Sun: magnetic fields — Sun: p...

Magnetic elds are thought to play a role in a wide variety of important astrophysical processes, from angular momentumtransport and jet formation in accretion disks to corona formation in stars. Unfortunately, the dynamics of magnetic elds in astrophysical plasmas are extremely complicated, and the success of current theoretical models and computer simulations seems to be inversely correlated w...

Systems consisting of magnetic particles embedded in a silica matrix have been used in magnetic recording, their study being thus an actual theme of research. In this work, we report some of the main results of a systematic study conducted to determine properties of the magnetic phases of the system Co2SiO4. The study also deals with the magnetic parameters of the composites Co2O3±SiO2, in an a...