Solar Coronal Jets Extending to High Altitudes Observed during the 2017 August 21 Total Eclipse

Abstract

Coronal jets, which extend from the solar surface to beyond 2 R ⊙ , were observed in the polar coronal hole regions during the total solar eclipse on 2017 August 21. In a time-series of white-light images of the corona spanning 70 minutes taken with our multi-site observations of this eclipse, six jets were found as narrow structures upwardly ejected with the apparent speed of about 450 km s −1 in polar plumes. On the other hand, extreme-ultraviolet (EUV) images taken with the Atmospheric Image Assembly of the Solar Dynamics Observatory show that all of the eclipse jets were preceded by EUV jets. Conversely, all the EUV jets whose brightness is comparable to ordinary soft X-ray jets and which occurred in the polar regions near the eclipse period were observed as eclipse jets. These results suggest that ordinary polar jets generally reach high altitudes and escape from the Sun as part of the solar wind.

On the Nature of Propagating Intensity Disturbances in Polar Plumes during the 2017 Total Solar Eclipse

“…It is noted from the eclipse and LASCO images that the plumes (L1, C, and R1) in the middle are brighter and more extended into the higher corona than the others (L2 and R2). The plumes, 'L1', 'C', and 'R1' correspond to the coronal fine structures, '3', '2', and '1', respectively, in the Figure 1 of Hanaoka et al (2018).…”

“…Based on the multi-site WL observations during the 2017 TSE, Hanaoka et al (2018) reported that these plumes are associated with the coronal (eclipse) jets, while the L2 plume is not accompanied by WL jets seen during the eclipse. According to their study, the jets associated with the plumes were upwardly ejected with an apparent speed of about 450 km s −1 beyond 2 R ⊙ .…”

Solar eclipses as a chance for professional-amateur scientific collaboration

“…The professional and amateur collaboration for the observation of the solar eclipses in Japan, which has been continued for more than ten years, have really produced some scientific results (Hanaoka et al 2012;Hanaoka et al 2014;Hanaoka et al 2018). Most of the cutting-edge astronomical observations require expensive, sophisticated instruments, but, on the contrary, imaging observations of the solar eclipses can be carried out with small telescopes.…”

Images and Spectra of the 2017 Total Solar Eclipse Corona From Our Oregon Site

“…Tian et al (2017) and Chen et al (2018) have described the coronal configuration and a coronal cavity over a prominence region, which also shows on our images. Hanaoka et al (2018) have described changes over an expanse of umbral motion across the United States. Figure 4 shows a sample slitless spectrum, taken several seconds before 3rd contact, showing the forbidden [Fe X] coronal red line at 637.4 nm and the forbidden [Fe XIV] coronal green line at 530.3 nm as well as chromospheric lines at low heights above the limb.…”