Wednesday, October 3, 2012

The First of the Fall Maneuvers is Today

Today at 1830 UTC (2:30 pm ET) we will perform the HMI roll maneuver. The images are usually oriented to solar north before we see them, but sometimes we get the watch the Sun appear to spin around. It keeps the instruments in good shape and allows the scientists to study the shape of the Sun. A recent article in Science magazine describes the surprising result that came from combining SDO and other measurements of the solar shape. The Sun is slightly oblate but less so than expected and without a change over the solar cycle.
More data is needed to understand why the Sun doesn't quite behave as we think it should.