Overview of the FLOYDS instruments

FLOYDS are a pair of nearly identical, low dispersion, robotic spectrographs deployed at the 2m Faulkes Telescopes, North and South (FTN and FTS). The instruments were designed with supernova classification and monitoring in mind, with a large wavelength coverage (\(\sim\)320 to 1000 nm) and a resolution (R\(\sim\)300 to 600, depending on wavelength) well-matched to the broad features of these events.

The design uses a low dispersion grating (235 l/mm) and a cross-dispersed prism in concert to work in first and second order simultaneously. A folded all-reflecting camera focuses first and second order light onto the CCD. This allows a \(\sim\)320 to 1000+ nm wavelength coverage in a single exposure. A 30“ slit length allows both orders to fit on the chip with no order overlap (Figure \ref{fig:floydsformat}). Four such slits widths are available at each spectrograph: 1.2”, 1.6“, 2.0”, and 6.0".