Globular clusters in Scorpio: Messier 4 (Robotic, NM)
This is a little more interesting than M3 and M5 in some respects. Its obvious optical characteristic is a straight bar of bright stars running almost vertically along the core.
Its line of sight also puts it very close to the Rho Ophiuchus complex of stars and dust clouds - its not that far from the Antares nebulosity/dust cloud.
My orginal image (before PixInsight processing) had quite a background gradient of red/yellow to the left which was probably the edge of the dust cloud lit up by the red supergiant Antares.
Almost the first processing step in PixInsight is to remove background gradients! I considered saving the extracted gradient and blending it back in again but left it in the end.
My next GC will be NGC 6144, which lies right behind the Antares nebulosity/dust cloud.
19 x 6 min exposures, dithered and drizzled. Post-processed in PixInsight 1.8. Acquired remotely from iTelescope T3 in NM.
Globular clusters in Scorpio: Messier 4 (Robotic, NM)
This is a little more interesting than M3 and M5 in some respects. Its obvious optical characteristic is a straight bar of bright stars running almost vertically along the core.
Its line of sight also puts it very close to the Rho Ophiuchus complex of stars and dust clouds - its not that far from the Antares nebulosity/dust cloud.
My orginal image (before PixInsight processing) had quite a background gradient of red/yellow to the left which was probably the edge of the dust cloud lit up by the red supergiant Antares.
Almost the first processing step in PixInsight is to remove background gradients! I considered saving the extracted gradient and blending it back in again but left it in the end.
My next GC will be NGC 6144, which lies right behind the Antares nebulosity/dust cloud.
19 x 6 min exposures, dithered and drizzled. Post-processed in PixInsight 1.8. Acquired remotely from iTelescope T3 in NM.