A Solar Jet Triggered by a Decaying Satellite Sunspot

In this paper, we analyze in detail a solar jet event triggered by magnetic reconnections in the lower atmosphere of the Sun. On 1 August 2014, the solar jet occurred at a satellite sunspot on the edge of the National Oceanic and Atmospheric Administration (NOAA) active region 12127. It was composed of an Hα surge, an ultra-violet (UV) jet, and Extra Ultra-violet (EUV) hot, and cool jets. The TiO images taken by the Goode Solar Telescope (GST) at the Big Bear Solar Observatory (BBSO) show that the satellite sunspot has successively decayed during the solar jet, and its area reduced by 80% till the end of the jet. Line-of-sight photospheric magnetic field observations by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) show that the negative magnetic polarity corresponding to the satellite sunspot was obviously cancelled with the adjacent positive magnetic field, which might result in the brightenings of the jet footpoint source. According to the observations by the Atmospheric Imaging Assembly (AIA) onboard SDO, the footpoint brightenings firstly appeared at 1600 Å. When the UV jet erupted from the top of the 1600Å footpoint source, the corresponding source could be observed at the EUV passbands. Afterward, the obvious EUV cool jet and Hα surge erupted from the side of the footpoint source as it became much brighter. The surge was composed of lots of ultra fine loops rooted in the southeastern side of the footpoint as revealed by the GST high resolution Hα observations. Multi-wavelength observations from the photosphere, through the chromosphere, to the corona suggest that magnetic cancellations at the middle or lower chromosphere may be the trigger of the solar jet event. The erupting mass flow of the solar jet can bring the energy flow up to the higher atmosphere (the transition region and the corona), and heat the higher atmosphere. Our results indicate that magnetic reconnection at the lower atmosphere may play an important role in the corona heating