Supernovae of type Ia (SNe Ia) are confirmed to be the best distance indicators to derive the cosmic expansion rate. The dispersion of their peak lumi nosity at
We find that five sources listed in the new carbon star catalog are not really carbon-rich objects but oxygen-rich stars, because they all have the prominent 10
We report results from a multi-wavelength study of the 3B/X1.2 tworibbon disk flare (S15E44), which was well observed by both ground-based and space-borne instr