The HMI data-collection scheme was changed on 13 April 2016 to reduce noise in the vector magnetic field measurement. Starting at 19:24, the Stokes data series hmi.S_720s has been computed by combining filtergrams from both HMI cameras.
HMI and MDI both captured the Mercury transit in May 2016. We have created composite images showing the transit in its entirety.
A realistic MHD simulation driven directly by SDO/HMI vector magnetograms reproduced a solar eruption in a non-potential flux-emerging active region.
An atypical X-shaped-ribbon flare provides evidence for 3D magnetic reconnection at a separator.
The F10.7 microwave flux shows remarkabke agreement with the unsigned magnetic flux from MDI and HMI over the past 20 years, attesting to the accuracy and significance of both.
We observed magnetoacoustic waves propagating along the magnetic field lines of a sunspot. Based on the wave periods and atmospheric characteristics, we reconstructed the magnetic field topology of the sunspot.
The HMI team has developed several Python codes that can be used to conveniently analyze its many magnetic field data products. Check it out!
The magnetic twist of a flux rope is carefully calculated for an active region model. The flux rope is close to the threshold of helical kink instability and has powered a series of eruptions.
Tiny sunspots, or pores, might have escaped the observers during the Maunder minimum. However, they might have carried enough magnetic flux for the normal operation of a Babcock-Leighton-type dynamo.
Data-driven magnetofrictional model provides a more realistic description of the non-potential coronal magnetic field, but faces technical challenges that need to be addressed.