Heesu Yang

SIMULTANEOUS OBSERVATION OF A HOT EXPLOSION BY NST AND IRIS

We present the first simultaneous observations of so-called “hot explosions” in the cool atmosphere of the Sun made by the New Solar Telescope (NST) of Big Bear Solar Observatory and the Interface Region Imaging Spectrograph (IRIS) in space. The data were obtained during the joint IRIS-NST observations on 2014 July 30. The explosion of interest started around 19:20 UT and lasted for about 10 minutes. Our findings are as follows: (1) the IRIS brightening was observed in three channels of slit-jaw images, which cover the temperature range from 4000 to 80,000 K; (2) during the brightening, the Si iv emission profile showed a double-peaked shape with highly blue and redshifted components ( and 80 km s−1); (3) wing brightening occurred in Hα and Ca ii 8542 Å bands and related surges were observed in both bands of the NST Fast Imaging Solar Spectrograph (FISS) instrument; (4) the elongated granule, seen in NST TiO data, is clear evidence of the emergence of positive flux to trigger the hot explosion; (5) the brightening in Solar Dynamics Observatory/Atmospheric Imaging Assembly 1600 Å images is quite consistent with the IRIS brightening. These observations suggest that our event is a hot explosion that occurred in the cool atmosphere of the Sun. In addition, our event appeared as an Ellerman bomb (EB) in the wing of Hα, although its intensity is weak and the vertical extent of the brightening seems to be relatively high compared with the typical EBs.

Intensity and Doppler velocity oscillations in pore atmospheres

We have investigated chromospheric traveling features running across two merged pores from their centers at speeds of about 55 km s−1, in the active region AR 11828. The pores were observed on 2013 August 24 by using high-time, spatial, and spectral resolution data from the Fast Imaging Solar Spectrograph of the 1.6 m New Solar Telescope. We infer a line-of-sight (LOS) velocity by applying the lambdameter method to the Ca ii 8542 A band and Hα band, and investigate intensity and LOS velocity changes at different wavelengths and different positions at the pores. We find that they have three-minute oscillations, and the intensity oscillation from the line center (0.0

Superpenumbral Fibrils Powered by Sunspot Oscillations

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Chromospheric Plasma Ejections in a Light Bridge of a Sunspot

) is preceded by that from the core (−0.3

OBSERVATIONS OF A SERIES OF FLARES AND ASSOCIATED JET-LIKE ERUPTIONS DRIVEN BY THE EMERGENCE OF TWISTED MAGNETIC FIELDS

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MAGNETIC-RECONNECTION GENERATED SHOCK WAVES AS A DRIVER OF SOLAR SURGES

) of the bands. There is no phase difference between the intensity and the LOS velocity oscillations at a given wavelength. The amplitude of LOS velocity from the near core spectra (

DEVELOPMENT OF THE FAST IMAGING SOLAR SPECTROGRAPH FOR 1.6 m NEW SOLAR TELESCOPE

{\Delta }\lambda =0.10-0.21\;\overset{\circ}{\rm A}

Observation of a Large-scale Quasi-circular Secondary Ribbon Associated with Successive Flares and a Halo CME

) is greater than that from the far core spectra (

Development of the camera lens system for total solar eclipse observation (Conference Presentation)

{\Delta }\lambda =0.24-0.36\;\overset{\circ}{\rm A}

A NEW METHOD TO DETERMINE THE TEMPERATURE OF CMES USING A CORONAGRAPH FILTER SYSTEM

). These results support the interpretation of the observed wave as a slow magnetoacoustic wave propagating along the magnetic field lines in the pores. The apparent horizontal motion and a sudden decrease of its speed beyond the pores can be explained by the projection effect caused by inclination of the magnetic field with a canopy structure. We conclude that the observed wave properties of the pores are quite similar to those from the sunspot observations.