Saturday, July 19, 2014

This Week in SDO

On July 9 SDO did the EVE FOV and HMI/AIA Flatfield maneuvers. You may have seen the images from AIA wiggle and blur during these maneuvers. This is a normal part of running a solar observatory in a geosynchronous orbit.

This week we have the EVE cruciform maneuver on Wednesday, July 23. On Saturday, July 26 we will have a lunar transit. Here is a short movie showing how the Moon moves through the SDO field of view. The transit lasts from 1457–1542 UTC (10:57-11:42 a.m. ET).

It isn't a very long transit, nor does the Moon cover a lot of the Sun. SDO will watch two more lunar transits this here, so stay tuned.

The Sun had a spotless day on July 17! According to the SIDC there were no sunspots on the Sun that day. The average sunspot number for 2014 remains at 90, even though the daily value has been as high as 150. This was the first spotless day since 2011. Unlike the spotless days in 2009-2011, several small sunspots appeared that day. They weren't seen at the earlier time used by the official observer. Here is an HMI with the sunspot circled.

They were pretty small sunspots!