S 
+

COBE Seeks Universe' First Blush

1. Measure cosmic microwave background (ubiquitous hiss relic of the intense heat of the early universe) detectors see nearly featureless sea of matter created by the big bang. 2. Cosmic IR background : (Diffuse IR background experiemnt DIRBE) - black holes and swarms of brilliant objects quasars NOT part of the early universe. 3. DIRBE knows they are old stars since the earliest stars don't contain anything heavier than He (which can only be produced by fusion) /*---------------------------------------------------------------------*/ S +

ULYSSES ABOVE The Sun's South Pole : An Introduction

-Ulysses has explored the field and particle environment of the sun's polar region. The solar wind speed was fast and nearly constant above -50 latitude. Compositional differences were observed in slow (low-latitude) solar wind and in fast (high-latitude) solar wind. The radial magnetic field did not change with latitude, implying that polar cap magnetic fields are transported toward the equator. The intensity of galactic cosmic rays was nearly independent of latitude. Their access to the polar region is opposed by outward-traveling, large amplitude waves in the magnetic field. /*---------------------------------------------------------------------*/ S +

The Heliospheric Magnetic Field over the south polar region of the sun

-B fields measured from ulysses over the south polar region of the sun show that the structure and properties of the 3D heliosphere were determined by the fast solar wind flow and B fields from large coronal holes in the polar regions of the sun. -11year solar activity cycle. /*---------------------------------------------------------------------*/ S +

Over the Southern Solar Pole: Low-energy interplanetary charged particles.

-Heliosphere instrument for spectrum, composition and anisotropy recorded the fluxes of low-energy ions and electrons when ulysses crossed the southern solar polar region and revealed large scale structure of the heliosphere to at least -75degrees was significantly influenced by the near-equatorial heliospheric current sheet. Electrons in particular were accelerated by the current sheet-produced and poleward-propagating interplanetary reverse shock at helioradii far from the ulysses location. At heliolatitudes higher than 75degrees on the ulysses ascent to the pole and -50 on the descent, small, less regular enhancements of hte lowester energy electron fluxes were measured whose relations to the current sheet were less clear. The anomalous component of the low energy oxygen flux at the highest heliolatitudes was -10^-8 per steradian ; the anomalous Ne/O ratio was .25 /*---------------------------------------------------------------------*/ S +

Observations of energetic particles with EPAC on ulysses in polar latitudes of the heliosphere.

-Measurements w/ energetic particle composition instrument (EPAC) aboard ulysses show particles from near the ecliptic that were accelerated by shocks from corotating interaction region. Particles were detected with the shocks . Particles could have reached these latitudes along B fields; such connections to the outer lower latitude heliosphere do not exist above that latitude. Accelerated streams have composition similar to solar wind abundances, no dispersion and a net inward anisotropy. The underlying composition between the recurrent stream is similar to the anomalous component of cosmic rays. The channel sensitive to high-energy protons shows a 26day variation of the flux superimposed on the heliospheric modulation of the galactic ions. /*---------------------------------------------------------------------*/ S +

Cosmic Ray and Solar Particle Investigations over the south polar regions of the sun

-Galactic cosmic radiation & component nuclei w/ charged particle sensors showed heliospheric B field structure over south solar pole. Fluxes of galactic cosmic rays and anomalous component increased w/ latitude. So modulated cosmic ray nucleon, electron and component fluxes are spherically symmetric in inner solar system. /*---------------------------------------------------------------------*/ S +

Corotating variations of cosmic rays near the south heliospheric pole.

heliospheric modulation of galactic cosmic ray protons show corotating variations in the intensity can persist to high heliographic latitudes. Variations seen at latitudes higher than latitude extension of the heliographic current sheet in regions of solar wind velocity and B field show no significant variation. Similar conclusions may apply to lower energy particles, which may be accelerated at lower latitudes. Cosmic ray variations caused by corotating interaction regions present at low heliographic latitudes can propagate to significantly high latitudes. /*---------------------------------------------------------------------*/ S +

Ulysses Radio and Plasma Wave observations @ high southern heliographic latitudes.

-indicate variations in rate of electric and B wave events as a function of heliographic latitude, distance and phase of the solar cycle. -Short bursts of electrostatic and electromagnetic wave found w/ depressions in B field called B holes. Extensive wave activity in B clouds from electron-ion temperature ratios. Lower number of intense in situ wave events at high latitudes was likely due to the decreased variability of the high latitude solar wind. /*---------------------------------------------------------------------*/ S +

Ulysses Solar Wind Plasma Observations @ High Southerly Latitudes

-Recurrent high speed streams and corotating interaction regions dominated middle latitudes. Speed of solar win 750km/s. Corotating reverse shocks persisted farther south (due to tilt of heliomagnetic streamer belt). Sporadic coronal mass ejections seen. Proton temperature high and electron strahl broader at higher latitudes. High-latitude wind contained compressional, pressure-balanced and Alfvénic structures. /*---------------------------------------------------------------------*/ S +

Southern High speed stream: Results from the SWICS Instrument on Ulysses

High speed solar wind streaming from southern coronal hole was uniform and steady confined by sharp boundary extending to the corona and chromosphere. Charge state measurements indicate that the electron temperature in this coronal hole reached a max of 1.5mil kelvin in 3 solar radii of the sun. Lack of depletion of heavy elements, suggests that an additional source of momentum is required to accelerate the polar wind. --fin