Observations of the Venus Transit across the Solar Hα Chromosphere in June 6, 2012

The solar telescope for full-disk observation of the Yunnan Observatory has been used for conventional observations of the solar Hα chromosphere, as well as other related studies of solar physical 34. We used this telescope for obtaining two complete sets of images of the Venus transits across the solar Hα full-disk in June 6, 2012 and June 8, 2004. The Venus transits, which were in the southern and northern high heliographic-latitude regions, respectively, did not appear to cross any area of solar activity or other unusual phenomena. While observing a Venus transit, the telescope also monitored the solar Ha chromosphere for potential solar activities and special events. In total 338 images (in the FITS format) were taken for the Venus transit in June 6, 2012. Abnormal shade phenomena occurred around the Venus in the raw images. Through the inspection and conventional image analysis (e.g. the median filtering), we speculate the abnormal shade phenomena are instrumental effects, possibly caused by the contribution of the telescope optics system, monochromatic ray diffraction, the atmospheric seeing, etc. Further research and analysis from various disciplines are needed for a more conclusive explanation of the phenomena. The paper describes in detail the results for the Venus transit in June 6, 2012.