HOP 0516

abstract of observational proposal

Main Objective: EIS observations of limb active region/prominence with magnetic field measurements in support of ground based observations of total eclipse 12 August 2026

Scientific Justification: Eclipses provide a rare opportunity to observe the solar corona in the visible from the ground with minimal contamination from the Earth's atmosphere. Spectroscopic observations from ground based instruments have provided a wealth of results for the formation of the solar wind, the properties of CMEs, and the long term evolution of the solar corona. Coordination with EIS EUV spectra will ensure a much better diagnostic coverage of the properties of the solar corona, and may lead to measurements of the absolute abundance of the elements that EIS observe. Furthermore, the newly developed magnetic field diagnostic techqniue utilizing Fe X EUV lines will provide magnetic field strength measurements for the first time, to be coupled with ground based observations and simulations of the solar corona by the 3D global MHD model AWSoM.

remarks

Dates: Start date: 12 August 2026; End date: 12 August 2026. Only 1 observation (cam_ar_limb_lite, raster ID=344) is required during totality.

Time window: Totality starts at 16:58 UT and ends at 18:34 UT so we request that the one raster we need includes this time span.

Target(s) of interest: Active region at the limb (west limb preferred, but anywhere is fine). If AR includes prominence, that is even best. If there is no active region available, then go to the base of a streamer.

Previous HOPs: None

Additional remarks:
This observation will be done at the same time that Prof. Shadia Habbal will carry out her own observations from the ground at 2-3 different places along totality. AWSoM global 3D MHD simulations of the solar corona and solar non-equilibrium spectra in the visible and EUV will be performed by Dr. Judit Szente (Boston University). Dr. Enrico Landi will ensure coordination with Habbal's team and Dr. Szente.