Plasma Ejections from a Light Bridge in a Sunspot Umbra
نویسندگان
چکیده
We present conspicuous activities of plasma ejections along a light bridge of a stable and mature sunspot in NOAA 8971 on 2000 May 02. We found the ejections both in the Hα (10 K) images obtained with the Domeless Solar Telescope (DST) at Hida Observatory, and in the 171 Å (Fe ix/x, ∼106 K) images obtained with the Transition Region and Coronal Explorer (TRACE). Main characteristics of the ejections are as follows: (1)Ejections occur intermittently and recurrently, (2)The velocities and the timings of the 171Å-ejections are the same as those of Hα ejections, (3)The appearance of ejections are different from one another, i.e. the Hα ejections have jet-like appearance, while that of 171Å-ejections is like a loop. Subject headings: Sun : activity — Sun : chromosphere — Sun: corona — sunspots
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