Following the Agreement between IAC and NOTSA for the continued operation of the Nordic Optical Telescope (NOT), 5% of the observing time at NOT is offered for joint IAC-Nordic research programs: this is known as the IAC-Nordic Observing Time. This observing time is aimed at reinforcing the collaboration and synergies between the IAC and the Nordic communities through joint programs. The IAC-Nordic program consists of 7/8 nights per semester, and is offered twice per year through special calls for proposals. Different types of programs can be presented – full or half nights, long term observations – but those proposals looking for strong scientific impact by means of collaboration and synergies between both communities during long periods will be especially considered. Observations will be in visitor mode. Owing to the special nature of the observing time, the conditions for its use differ from those of normal TAC/CAT time. The main features of IAC-Nordic Time are:

• Any IAC and Nordic research group may apply for this kind of observing time provided that they carry out a joint research and at least one member from each community appears as co-investigator on the proposal. If there are more than four people on the proposal there must be at least two from each community.
• Proposals must be presented before the deadline announced in the corresponding call for proposals.
• Proposals shall be made in a format similar to that of normal CAT proposals. See below (or see instructions for further details).

8 nights are available for semester 2019A (April – September  2019) with any of the NOT core instruments. The deadline for proposal submission is Monday, 10 December 2018, at 17:00 h Canarian time (18:00 h CET). 

Instrumental updates with respect to previous semesters are as follows:

• A new fiber bundle, using octagonal fiber, was installed in FIES. This new bundle is expected to improve the radial-velocity stability. Preliminary tests have shown the stability with the high-resolution fiber to be ~2 m/s on time-scales of a day, and below ~4 m/s on longer time-scales. More extensive tests are on-going. The medium-resolution fiber is now also working, and tests have shown the stability to be similar to that of the high-resolution fiber. More extensive tests are on-going.
• We acquired a holographic diffuser to do high-precision photometry. The diffuser effectively scrambled the incoming light, providing a more constant and optimal (`top-head’) shape, with minimal light  loss, significantly reducing any systematic effects in the photometry. The diffuser provides a very stable stellar image with a width (~FWHM) of 5.46 arcsec. A second diffuser, giving a stellar image with a width of 8 arcsec, is expected to arrive soon.
• The SOFIN high-resolution Echelle spectrograph is again available. It is offered only to do  circular spectro-polarimetry with the medium-resolution (R~80,000) camera. SOFIN is not a common-user instrument: only limited support is provided, and explicit approval for a proposal should be obtained. 

NOTE: During the IAC-Nordic time in semester 2019A, regular Nordic and CAT Target of Opportunity (ToO) programs are allowed to override IAC-Nordic time (except for time critical observations like planetary transit events, as decided by the joint Time Allocation Committees) according to the following rules:

• No more than 3 h per night (or 4 h per night, see next) can be overriden: in case of various ToO alerts are received from different programs of a given Time Allocation Committee (TAC), priority will be given to the highest ranked program. In case of competing CAT and Nordic ToO programs which aim for the same science/targets, ONLY JOINT triggers will be accepted. In case of CAT and Nordic ToO programs with different scientific objectives and targets, if triggers are active on the same night, both can be executed up to a maximum of 4 h. The details of how these two later cases can be arranged are to be agreed with the joint TACs.
• The time observing lost to ToOs will be compensated to the Principal Investigators (PIs) according to the Nordic rules in case of Nordic ToO programs and during the CAT service time (whenever the requested instrument is available) in semesters 2018A and 2018B in case of CAT ToO programs.
• Any IAC-Nordic PI affected by ToO observations should apply for specific observations to compensate for the observing time lost during the IAC-Nordic time through the NOT Fast-Track Service Program in case of Nordic ToOs and through the CAT Service formin case of CAT ToO programs (in the CAT form, please indicate clearly that your application is to compensate the time lost to ToO during the IAC-Nordic time, and provide the ToO program code).
• The list of approved ToO programs are available on Nordic ToO programs (click on the corresponding semester and go to the end of page) and CAT ToO programs.