MSC candidate TANG Zehao, from Yunnan Observatories of the Chinese Academy of Sciences, and his cooperators firstly reported sympathetic standard and blowout coronal jets from two nearby coronal bright points in a polar coronal hole. Their research was published on The Astrophysical Journal Letter a few days ago.

Coronal jets, mainly triggered by the magnetic reconnection, are very pervasive in the solar atmosphere. They are heated plasmas flows moving along magnetic field lines showing as collimated or two-sided ejections. Besides solar jets, there exist many kinds of successive solar eruptions during a relatively short time interval in the solar atmosphere. These phenomenon occurring at different sites and showing internal physical connections were called sympathetic eruptions. Before then, sympathetic eruptions among the wave and filament, different flares, different coronal mass ejections (CMEs) and different filaments have been reported, but sympathetic solar jets have not yet.

To investigate the sympathetic solar jets, TANG and his coauthors diagnosed two successive coronal jets occurring in the south polar coronal hole on 2019 March 31, using data of X-ray, extreme ultraviolet wavelengths, and also photospheric magnetograms. In this event, two jets emanated from two adjacent coronal bright points (CBP1 and CBP2) successively. The first jet (jet1) was characterized by a typical inverted-Y (or cusp) and its lateral motion, suggesting that it was a standard jet and triggered by the magnetic reconnection between CBP1 and ambient field.

The second jet (jet2) erupted successively after the first jet impinged upon its nearby CBP2. The trigger of jet2 is observationally evidenced to be the magnetic reconnection between jet1 and CBP2, suggesting that these two successive jets are connected with each other physically. In addition, the authors also found a strong twisted structure within jet2's base, which eventually erupted, resulting in the dramatically brightening of the jet base and the broadening of the jet spire. Thus, the second jet is a blowout jet. Therefore, these two successive jets are sympathetic standard and blowout jets.

Solar jets are a ubiquitous phenomenon in the solar atmosphere. They may be the potential explanation for solar wind and even spicules, and thus studying solar jets is of significant importance. They are usually triggered by the internal magnetic activities, i.e., magnetic emergences and cancellations. This study indicates that besides the internal triggers, coronal jets can be triggered also by external eruptions or disturbances. (within 10 days)

Contact:

SHEN Yuandeng, Yunnan Observatories, CAS

ydshen@ynao.ac.cn