Bright Points (BPs) are small-scale brightness enhancements located in the Sun. Previous works usually focus in the visible wavelengths and X-ray, EUV or even radio band, but the UV band are studied rarely due to the observation limits. However, the SDO/AIA works at multi-wavelength with a broad temperature range, which gives us a chance to study the BPs at UV band, such as at 1600 Å and 1700 Å, and we can study the relationship between the UV 1600BPs and magnetic polarities or bipoles with the SDO/HMI data.

In our paper, we use the threshold method to determine the UV 1600BPs and magnetic polarities.

That is to say, UV 1600BPs are determined from the bright regions with a brightness above the mean value of the background plus the three times of background deviation and with an area above 25 pixel2 (9.324 arcsec2), while individual magnetic polarity has a strength greater than the mean value of the background plus the two and half times of background deviation and an area greater than 5 pixel2 (1.272 arcsec2).And magnetic bipoles are identified as a pair of positive and negative polarities with a shortest distance between them. Finally, we identified 2722 UV 1600BPs and 2850 magnetic bipoles from 19 to 25 in August 2010. We find that only 29.6 %

(806/2722) UV 1600BPs display a good correlation with magnetic bipoles, while about 64.3 % (1749/2722) UV 1600BPs show one-to-one correspondence to the magnetic polarities, regardless of the positive and negative polarities, this is an observational constraint for the origination mechanism of UV 1600BPs. For these magnetic bipoles associated with UV 1600BPs, we find that their orientation angles are distributed randomly along the equator.

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　   SDO/HMI magnetograme on 25 August 2010　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　  　  The bipolar orientation angle (α) distribution

(by LI Dong)

The study has been adopted by ASTROPHYSICS AND SPACE SCIENCE, 2012, Vol. 341 No. 2 　pp.215-224　  http://www.springerlink.com/content/lv1jk5783755r2j2/