Instrumentation

You can find a simpler description of telescope instrumentation on the National Schools' Observatory website.

The NRT will perform fast follow-up observations of transients in the new era of multi-wavelength synoptic surveys. The telescope design specification allows an operable wavelength range of 300 – 2400 nm, while delivering an image quality not exceeding site seeing + 0.2 arcseconds in terms of 80% diffracted encircled energy. The time-to-target requirement following an alert is 30 seconds and as such the instrumentation should allow the object to fall onto the detector FOV within the blind pointing accuracy of the telescope (10”x10”; 99.9% of the time minimum).

 

The instrumentation for the NRT will be stable, efficient and cater to the needs of the time-domain community. Light from astronomical sources can be probed in six dimensions: through two polarisation states, temporally, with respect to wavelength dependence, and intensity in the two spatial directions as projected on the sky. A complex modern instrument may probe all dimensions, however these require large amounts of optics and tend to lead to poor overall instrument throughput. Such a combined instrument would not fit into the instrument envelope proposed for the NRT. Hence, imaging, spectroscopy and polarimetric measurement systems have been designed independently. Based on an analysis of the science case we are proposing a two generation instrumentation plan for the NRT, with the possibility of including a wide-field imager in addition to the proposed first and second generations below.

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A selection from the full set of NRT science requirements which are used to dictate the first and second generation instrumentation suite.

Éamonn Harvey

The first light instrumentation will likely be a set of low-cost, simple, high-throughput instruments designed to deliver the NRT science cases. The first light suite will consist of spectroscopic and photometric capabilities (e.g. NR-SPRAT and NR-IMAGER) as well as the transfer of two existing instruments from LT to NRT (NR-MOPTOP and NR-RAPTOR) to cover polarimetry and near-Infrared (NIR) imaging.

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Resolution vs wavelength capabilities of the NRT first light instrumentation suite

Éamonn Harvey

Éamonn Harvey

The proposed second generation of instrumentation is designed to complete the overall science requirements of the project. The major additions to the instrumentation suite are the introduction of a wide-field camera, a red, sensitive, imaging spectrograph, a medium-resolution, single-shot, broad-wavelength spectrograph and a full Stokes polarimeter, as summarised in the table and figure below:

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Éamonn Harvey

The prioritisation of certain instrumentation depends on changes to the funding landscape and science case motivation, however, the second generation instrument suite demonstrates the wide range of capabilities the NRT will have once full commissioning of the facility is complete.

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Éamonn Harvey

The NRT project is driven by collaboration and interaction with the worldwide time-domain astronomy community. If you wish to contribute your ideas or comments, please do contact us via the form below or by emailing NRT@ljmu.ac.uk. We welcome new members to our science working groups, to browse the different science cases please click on the button below.