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Solar rotation rate from minimum to maximum of activity cycle
Kumar, Brajesh; Tripathy, S. C.; Jain, Kiran +1 more
Using helioseismic data from SOI/MDI and GONG for the current solar cycle 23, from solar minimum to near maximum phase, we report here on the temporal variation of the rotation rate.
The Media Calibration System for Cassini Radio Science: Part III
Keihm, S. J.; Resch, G. M.; Lanyi, G. E. +5 more
A new media calibration system has been implemented at DSS 25. It is designed to calibrate the delay of radio signals imposed by the neutral atmosphere. The system provides periodic measurements, with intervals greater than 2 s, of both the static dry and fluctuating wet components of this delay. In particular, a water vapor radiometer calibrates …
A Cyclone on Mars: Observations in 1999
Teifel', V. G.
Observations of a cyclone in the Martian northern hemisphere from April 24 to April 27, 1999, are reported. The cyclone was revealed by the Hubble Space Telescope (HST), but later it was identified in CCD images obtained earlier by the author from April 24 to April 26 with the 0.6-m telescope of the Astrophysical Institute Observatory. The cyclone…
Space physics: Rhythms of the auroral dance
Newell, Patrick T.
Earlier this year, the four satellites of the Cluster mission passed through part of the electric circuit that causes aurorae. Their observations support the view that intense aurorae form in regions largely devoid of electrons.
Coherence of Charged Particle Oscillations in the Heliosphere (f∼5 µHz): Implications for a Solar Modulation Source
Kunow, H.; Lanzerotti, L. J.; Maclennan, C. G. +3 more
Time series analysis of low energy electron and high energy proton cosmic ray fluxes, both measured on the Ulysses spacecraft, shows that they are coherent in some frequency bands in the energy range 0-6 µHz, especially near 5 µHz. Interplanetary particle fluxes with very different kinematic properties (e.g., gyrofrequencies) are modulated coheren…
Solar cycle variations of GCR anisotropies at Ulysses
Fraenz, M.; Heber, B.; Blake, J. B. +1 more
The four telescope array of the EPAC investigation aboard Ulysses provides a good measurement of the anisotropy of the > 230 MeV GCR ux during those frequent time periods when MeV solar electrons are not present. We focused on the time period since late 1994 and found that the angular distribution of the GCR, as determined by the ratio of count…
Anomalous cosmic rays as a source of energetic neutral atoms in the heliosphere
Czechowski, A.
Anomalous cosmic ray (ACR) ions in the distant heliosphere are potentially one of the important heliospheric sources of energetic neutral atoms (ENAs), which derive from the energetic ions neutralized by charge exchange with low energy atoms of the background interstellar gas. ENAs are unaffected by magnetic fields and move almost freely over larg…
Cosmic Ray Elemental Source Composition: Observations with the Ulysses High Energy Telescope
Connell, J. J.; Burin de Roziers, E.
We will present new and revised measurements of cosmic ray source abundances from boron to nickel. The High Energy Telescope (HET) on the Ulysses spacecraft provides high resolution measurements of cosmic rays, separating elements from hydrogen to nickel for energies ranging from 40 to 400 MeV/u. We determine cosmic ray source abundances by compar…
BM Eri - SR-type Variable Star
Brukhanov, I. S.
BD +20o 1171 (= NSV 16732 = TYCHO 1320 91 1 = HD 39785 = SAO 077726) is a long-periodic pulsating variable star of SRc-type with a period of 20930d, range of variations in B 8.8m - 10.3m, and the most realiable maximum is JD 2443410.5
The Onset of Long Term Modulation in the Heliosphere in Cycle 23
Kunow, H.; Wibberenz, G.; Heber, B. +8 more
The combination of Voyager 1 (77.9 AU, 34.4° N) and Voyager 2 (61.2 AU, 24.5° S) at moderate heliolatitudes in the distant heliosphere and Ulysses with its unique latitudinal surveys in the inner heliosphere along with IMP 8 and other satellites at 1 AU constitutes a network of observatories that are ideally suited to study cosmic rays over the so…