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Recent Improvements for 2016B 07 March 2016

This report briefly highlights some of the recent advancements at the Liverpool Telescope which include both incremental improvements to existing facilities, such as the doubling of FRODOSpec throughput, and availability of entirely new facilities, such as the UV-optimised spectrograph LOTUS.

Both the primary and secondary mirrors were realuminised last summer. This is the first time the secondary has been recoated, and the result was a factor of ~2 improvement in throughput. Signal-to-noise estimates for all instruments are available using the LT exposure time calculator.
[Full story about the mirror recoating.]

Our instrument suite has been improved with some new instruments and upgrades to existing ones. Specifically:

FRODOspec, our high resolution fibre-fed spectrograph, was upgraded last autumn with a new deep-depleted CCD detector in the red arm. As well as significantly reducing fringing, this has improved sensitivity across the wavelength range 5800-9400 angstroms, by up to 100 per cent at some wavelengths. Combined with the overall telescope throughput improvement, this represents a significant enhancement to the capabilities of this instrument.
[Full story about the FRODOSpec upgrade.]

IO:I is the near-infrared imaging component of the IO suite of instruments, and following commissioning in 2015B is now seeing full science use. This instrument has a 6.3 x 6.3 arcmin field-of-view and a fixed H-band filter. We have the option of changing this filter on a semester-by-semester basis. Other options currently available are J-band or a split filter, in which half of the field (3 x 6 arcmin) uses a J filter and the other half H. We would be most interested in receiving feedback from potential science users as to their preferred option.

LOTUS is a low resolution optical-near UV spectrograph with wavelength coverage from 3200 to 6300 Angstroms at a dispersion of 4.7 Angstroms/pixel. This object was built and commissioned very quickly and at low cost in 2015 in order to participate in the observing campaign of comet 67-P alongside the Rosetta spacecraft. It is now offered for general science use. The instrument has a single fixed slit with "narrow" (2.5 arcsec x 95 arcsec) and "wide" (5 arcsec x 25 arcsec) regions. We have received some interest in deploying an even wider (>10 arcsec) slit for programmes of, e.g., exoplanet transmission spectroscopy. This is another topic on which we would appreciate feedback from the community.

SPRAT, our R~350, 4000-8000 angstrom long slit spectrograph, has gained the ability to use IO:O for acquisition rather than relying on its own limited field-of-view, which makes acquisition much more reliable in sparse fields.

The optical imaging cameras IO:O and RISE, and the three-arm fast readout polarimeter RINGO3, also remain in operation and will be available in 2016B. Though these have not had any specific upgrades in the past year, they do of course all benefit from the throughput improvements of the mirror recoating, especially at blue wavelengths. All are described on the LT Instrumentation web pages.

Turning to telescope performance, guided by specific priorities set by the LT Users Group a new pointing software algorithm has been deployed providing an expected RMS blind pointing error of 5arcsec for semester 16B, improved from the 10arcsec RMS at which we have long operated.

There have also been several usability updates recently in the LT data archive web-based search tools. During the past semester the archive exceeded two million publicly available science observations.
[Full story about the archive public data release.]