Astronomy Picture of the Day
    


Solar Neutrino Astronomy
<< Yesterday 17.05.2001 Tomorrow >>
Solar Neutrino Astronomy
Credit & Copyright: M. Weber & P. Sturrock (Stanford), J. Scargle (NASA / ARC),
SOHO / MDI, GALLEX / GNO
Explanation: Neutrinos are subatomic particles generated by the nuclear reactions which power stars like our Sun. Flying outward from the Sun's core, they easily pass through the Sun (and almost anything else!) unimpeded and should be detectable by earth-based neutrino "telescopes". Still, to the long-standing consternation of astrophysicists, the observed flux of solar neutrinos is less than expected. In a new twist to this solar neutrino saga, an analysis of data from the GALLEX / GNO neutrino detector finds a solar neutrino flux that varies over about 27 days ... approximately matching the Sun's rotation period. In fact, since different parts of the Sun rotate at different rates, the neutrino flux variations match most exactly the rotation rates of the areas shown in red on this colorful cross-sectional map of the solar interior rotation. So how could solar rotation affect the neutrino flux? Some theoretical models say that neutrinos can change quantum properties when they interact with tangled solar magnetic fields and become particles that the neutrino experiments were not designed to detect. Then, as the Sun rotates, the neutrinos sometimes come to us unaffected and sometimes come through magnetic fields, diminishing the flux that can be measured.

January
February
March
April
May
June
July
August
September
October
November
December
 < May 2001  >
Mo Tu We Th Fr Sa Su

123456
78910111213
14151617181920
21222324252627
28293031


Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: solar neutrinos - solar rotation - neutrino
Publications with words: solar neutrinos - solar rotation - neutrino
See also:
All publications on this topic >>