Qibin Li

A New View of Coronal Waves from STEREO

On 2007 December 7, there was an eruption from AR 10977, which also hosted a sigmoid. An EUV Imaging Telescope (EIT) wave associated with this eruption was observed by EUVI on board the Solar Terrestrial Relations Observatory (STEREO). Using EUVI images in the 171 A and the 195 A passbands from both STEREO A and B, we study the morphology and kinematics of this EIT wave. In the early stages, images of the EIT wave from the two STEREO spacecrafts differ markedly. We determine that the EUV fronts observed at the very beginning of the eruption likely include some intensity contribution from the associated coronal mass ejection (CME). Additionally, our velocity measurements suggest that the EIT wave front may propagate at nearly constant velocity. Both results offer constraints on current models and understanding of EIT waves.

Discovery of X-ray selected AGNs, white dwarf and cataclysmic variable☆

Abstract In order to investigate selection criteria for a ROSAT X-ray selected sky survey of bright nearby quasars, test observations were carried out on the 2.16 m telescope of Beijing Observatory between 1995 April and 1996 October. In the process 73 quasars, 27 Seyferts. 1 BL Lac candidate, 1 white dwarf and 1 cataclysmic variable were discovered.

Discovery of Five Bright Low-Redshift Quasars from ROSAT PSPC Sources 1

A program to identify bright ROSAT sources is being carried out with the 216-cm and 60-cm telescopes at Xinglong station. As the result of the first run, five bright low-redshift quasars have been discovered.

Optical observations of Comet Shoemaker-Levy 9 impacts on Jupiter

Abstract Part results of optical observations made at Fuzhou and Urumqi during the period of Comet Shoemaker-Levy impacts on Jupiter (1994 July 17–22), are given in this Note.