© Parts of this composite contain images published in Shaifullah et al (2020), Solar Physics and are used here under the Springer author reuse clause.
CMEchaser is a python-based software to detect the occultation of background sources by Solar coronal mass ejections (CMEs). The way the software works is displayed in the cartoon on the left. It first converts the celestial coordinates of the source, a distant pulsar in this example, to the khaki helioprojective plane where it is marked by the maroon star. It then checks if a CME moving out from the Sun, traced by the pink CME cone, will encounter the longer, dash-dotted line of sight from the Earth to the source. If such a crossing is detected, the software then produces the plots on the right.
The bottom right plot shows the source marked with a crosshair symbol, overplotted on images of the Sun at the CME launch time, taken from the Solar and Heliospheric Observatory (SOHO) and Solar Dynamics Observatory (SDO) spacecrafts. The top right plot shows the detection of an occultation of the line of sight to the pulsar J0034−0534 (indicated by the star symbol). The pulsar was observed on April 20, 2014 and was occulted by a halo CME launched on April 18. In this plot, the CME is shown by the mauve sector spanning the angular width of the CME (360 deg in this case) and the propagation is only drawn up to the solar elongation (in astronomical units, ua) of the pulsar. The field of view of the Large Angle and Spectrometric Coronagraph Camera 3 (LASCO C3, on board SOHO) is shown by the purple shaded circle and the gold circle in the centre of the plot denotes the Sun. The radial axis shows the Solar Elongation converted to a projected separation in fractional ua. The article describing CMEchaser has been accepted for publication in Solar Physics.