After nearly 20 years and several attempts, Optec has developed a new Near-IR photometer for small to medium size telescopes. Relatively new InGaAs PIN photodiodes designed for the fiber optics communication market have reached very high performance levels compared to the IR detectors of earlier times. It is now possible to design and build an IR photometer, which allows a great many stars to be observed accurately in the J (1250nm) and H (1650nm) photometric bands. Using custom J-band and H-band filters the SSP-4 allows amateur astronomers with 10 to 16 inch telescopes to perform a level of scientific measurement unheard of just a few years ago. The age of amateur level infrared photometry is finally upon us

The InGaAs PIN photodiode is the heart of the SSP-4 and is manufactured by Hamamatsu Corp. The series G5851-13 with a 1mm detector diameter and G5851-203 with a 0.3mm diameter are available to be mounted in the instrument. While harder to position over the object, the G5851-203 has considerable less noise and therefore is the prefered detector. The complete specifications for these detectors can be found in the manual or by clicking here to visit the Hamamatsu web site.

This level of instrumentation requires a large telescope with excellent tracking ability to fully appreciate the performance of the SSP-4. The SSP-4 can be used manually with input control via the two button interface or the supplied control program, SSP4Dataq, can operate the SSP-4 remotely with a PC. The SSP4Dataq program can operate the instrument and record the data but it has no provision for data reduction. This may change so check the Optec software update area often.

The AAVSO has assisted Optec in the development of this instrument and they have an active users group and much information concerning data reduction and program stars. Click here to go to the AAVSO SSP-4 web site.