Disk-unresolved solar light is fed to the spectrograph from a small Sun-as-a-star telescope via a fibre connection to the calibration unit. An integration sphere behind the telescope feeds two fibres to the spectrograph (note that the telescope was redesigned compared to the original description in the PEPSI technical paper in AN). SDI’s aim is, firstly, to provide an external comparison source for the instrumental profile and monitor its long-term stability and, secondly, to monitor the Sun over an entire magnetic activity cycle, among others.
Data rate 402GB/day , 32TB SAN storage for 60 d.
- The poster presents the optical spectrum of the Sun obtained with SDI can be downloaded from the news section.
- Partial Solar eclipse in 2017 was observed by SDI. Read more…