Letters of Intent received in 2018

LoI 2020-2035
Coronae observed from natural eclipses and man-made eclipses (Non-GA Symposium)

Date: 22 June 2020 to 26 June 2020
Location: Xiamen City, China, Nanjing
Contact: Zhongquan Qu (zqqu@ynao.ac.cn)
Coordinating division: Division E Sun and Heliosphere
Other divisions: Division B Facilities, Technologies and Data Science
Division C Education, Outreach and Heritage
Division G Stars and Stellar Physics
Co-Chairs of SOC: Zhongquan Qu (Yunnan Observatories, Chinese Academy of Sciences)
Jay Pasachoff (Williams College)
Chair of LOC: Junfeng Wang (Xiamen University)



1,Quiet coronal features and structures of both large scales and fine ones.
2,Variable and active coronae.
3,Coronal heating.
4,Coronal magnetic fields.
5,Coronal waves.
6,Solar and/or stellar wind acceleration.
8,Theories and simulations.
9,Scientific outreach of coronae for the public.



Solar and stellar coronae contain many mysteries to be uncovered for human beings. They attract great attention of not only astronomers but also ordinary people. Such mysteries remain partially due to the coronal observation being much more hardly carried out than photospheric or chromospheric ones.
Natural eclipses especially total ones provide a unique way to detect those coronal properties requiring the extremely low scattering light by the sky. And thanks to B. Lyot who invented coronagraph in 1930, researchers can observe it in visible light and infrared bands on the ground as the man-made eclipses, along with coronal radio observation. As the space technique is developed, space-borne coronagraphs as well as those instruments using EUV and X-ray bands can resolve the corona with high spatial resolutions.
The data have been accumulated as time goes, many progresses have been made and novel coronagraph techniques are continually developed, not only for solar corona but also stellar coronae. However, the prominent issues still stand there. For instance, mechanisms responsible for the coronal heating, solar and stellar wind acceleration as well as coronal variations and eruptions wait for answers.
It is a chance for us to organize a symposium from June 22 to 26, 2020 after the annular solar eclipse on June 21 at Xiamen, China. Not only the astronomers can share and exchange their ideas but also can the local people share the knowledges obtained by outreaches. Another main scientific goal is to obtain a complete picture about solar and stellar coronae update for the attendees.
Therefore, the following aspects will be emphasized and discussed during the meeting:
1. Quiet coronal features and structures of both large scales and fine ones. Discussion about their connections would be expected;
2. Variable and active coronae. The hottest topic in the coronal physics should continue, especially the mechanisms responsible for them and whether critical evidences supporting the mechanisms exist till then;
3. Coronal heating. Perhaps it is the biggest problem faced by solar and stellar physicists. Not only micro eruptions and waves are thought to be responsible, but also magneto-convection driven mechanism appears. Overall views may be needed;
4. Coronal magnetic fields. A hard topic tightly relevant to the other topics. The accurate spectropolarimetry data are rare and the reliable inversion problems remain to be solved;
5. Coronal waves. There are abundant coronal waves, and their transformations as well as origins should be further explored;
6. Solar and/or stellar wind acceleration. Many efforts have been paid, it stands still as an open questions;
7. Instrumentation. Coronagraphs have been designed for different coronal sciences. It will be time to show those novel telescopes, and discussion on whether more powerful facilities are needed for further discovery and identification of these mechanisms mentioned above will be encouraged;
8. Theories and simulations. It is expected that the new theories and simulation results will flourish every year, and their guidance for observations are reasonably hoped;
9. Scientific outreach of coronae for the public. As usual, it will be the great chance for astronomers to present the clear and easily-understanding coronal pictures for the public.

It is believed that the gathering of experts in the field of instrumentation, observation, data analysis as well as theory can improve our understanding of solar and stellar coronae by sufficient and efficient discussions, especially via inter-Division ones, and this is the purpose for the organization.

Location: Xiamen, China. A historic city, southeast coast.
Duration: June 22-26, 2020,just after the 2020 annular solar eclipse