Fast radio bursts are enigmatic transient sources that attracted many studies in the past 13 years. They are radio bursts that release a huge amount of energy within milliseconds time. For many years, they were only observed from very distant galaxies. Given the large distances, those extragalactic fast radio bursts remain mysterious events (find here a review by Emily Petroff). On Apr 28, 2019, an extremely bright millisecond-duration radio burst was caught from a magnetar in our Miky Way! The radio bursts were detected by two radio telescopes — Canadian Hydrogen Intensity Mapping Experiment (CHIME) and the Survey for Transient Astronomical Radio Emission 2 (STARE2).  They are powerful radio arrays…

Numerous black holes are hidden in the space. These compact objects are difficult to probe as light cannot escape from the strong gravities from them. Fortunately, some black holes are actively shaping their environment and in such a way, we could “catch” them. SS 443 is one of the most popular and active black hole systems that strongly influence its neighborhood. It is a young binary system that contains a 16 solar mass black hole accreting materials from a massive star orbiting around it (see Figure 1). The black hole was formed in a recent stellar explosion, which we call “supernova”. The recent time here means 20 thousand years ago,…

Our ancestors have been monitoring the night sky since 5000 years ago, making astronomy the oldest natural science. Most stars seen on the night sky have been there for millions to billions of years, except that they rise and descend along with the Earth’s rotation. But if one is very patient and lucky, one could see that the sky is changing. For astrological purposes and other reasons, the variation of the sky had been recorded by ancient astronomers. In addition to the comets and meteors, many transient events occur outside of our Solar systems. The astronomical term “transient” expresses the phenomena that some celestial objects switch on and off their…