urn:nasa:pds:context:instrument:ctio-cerro_tololo.smarts_1m50.cassegrainspec 1.4 1.25.0.0 Product_Context urn:nasa:pds:context:instrument:ctio.smarts1m5.cassegrainspec 2026-07-07 1.4 Removed duplicate Internal_Reference entries from Reference_List. 2025-12-24 1.3 Adding missing "facility" references. Adding missing "telescope" references. 2025-12-24 1.2 Updated schema version. Adding missing "facility" references. Adding missing "telescope" references. 2025-01-02 1.1 Updated schema version. Adding missing "telescope" references. 2021-12-07 1.0 per RMS, deprecated ctio in favor of ctio-cerro_tololo urn:nasa:pds:context:telescope:ctio-cerro_tololo.smarts_1m50 instrument_to_telescope urn:nasa:pds:context:facility:observatory.ctio-cerro_tololo instrument_to_facility CTIO 1.5-meter Cassegrain Spectrograph Spectrometer The CTIO 1.5-meter Cassegrain spectrograph is an ultraviolet transmitting grating spectrograph which is used at the f/7.5 focus where the scale is 18.1 arcseconds/mm. It is identical to the 2.1-meter telescope White Cassegrain spectrograph at Kitt Peak National Observatory and therefore allows one to obtain similar spectrograms in both hemispheres. Plate Scale (at f/7.5 focal plane) 18.06 arcsec/mm Slit Length 25.4 mm, 459.7 arcsec Collimator Focal Length 766.1 mm Point source collimated beam diameter 101.6 mm Collimator-to-Camera Angle 55 degrees Grating size 127[INVALID_PDS_CHARACTER]152 mm Camera Focal Length 160 mm Demagnification 4.788 Plate Scale (at detector) 86.7 arcsec/mm