Guidelines for visiting observers

1. Organising your travel

**All the observers are required to fill in and sign our Visiting Observer's Authorization Form and send it to our Visiting Astronomers Office well ahead of their observing run.**

1.1 INAF (or associate) staff observing in INAF-TAC programs

TNG organises and reimburses transportation to La Palma as well as accommodation within the island for one (1) astronomer per program.

As a general rule, the flight ticket is purchased directly by TNG and made available to the observer. The other services (accommodation, car transportation, meals, etc.) are also paid by TNG. Observers are requested to contact our Visiting Astronomers Office (VAO) at least two months before their observing run. TNG do not take any responsibility on problems arising from late contacts. Please note that TNG can only reimburse the cost of an economy airline ticket.

These rules hold also for INAF (or associate) staff observing at Nordic Optical Telescope (NOT), in the framework of the TNG-NOT common offer for observing time.

1.2 Other visiting observers

Airline tickets, hotels, accommodation and meals atop the mountain as well as transports within the island must be organized and paid directly by the observer; no financial support is provided by TNG.

Click here for travel and lodging information. Accommodation and meal services at the “ORM residencia” atop the mountain can be booked via the dedicated IAC web page; some help can also be provided by our VAO.

1.3 Possible financial support from OPTICON

Observers of proposals with PI and the majority of the team from EU member or associated states other than Italy and Spain, may access the TNG under the auspices of the EC-funded research infrastructure program OPTICON. Please note that a separate call for proposals is issued for OPTICON programs. Applicants are invited to read the OPTICON web pages for detailed information on eligibility and other aspects of the program. The travel of visiting observers of OPTICON programs may be organized by us, following the rules in section 1.1.

1.4 Communication concerning the movement of workers

According to the Spanish law 45/1999, the presence of people working for 8 or more days at the Canary Islands Observatories must be notified to the Spanish authorities by their employer, who should fill in this form (in Spanish) and send it by fax to +34 922473746 or +34 92247374. Here we show also a English version, intended only to explain the meaning of the required information.

1.5 Seminars

Visiting astronomers are welcome to give us a talk. Please contact our VAO for details.

1.6 Health issues

The Observatory site is located at an altitude of 2400 metres above sea-level. The closest hospital can be reached in about 1h20m, but this time could considerably increase in presence of snow or landslides on the road. Although a 2400m altitude is not usually a problem, a general health check in the past 12 months is recommended.

2. Rules while staying at the telescope

Only astronomers and/or students involved in the observing project are authorized to remain at the telescope during a normal observing night. Visiting astronomers may use a TNG car for transport on-site; the use of this car in some cases might be precluded. Note that using TNG cars outside the observatory area is not allowed.

Visitors with scarce observing experience are highly recommended to come accompanied by a more expert colleague. The full responsibility of the observations and calibrations is always within the observer.

The Visitor will be met by TNG Astronomer around 4 pm of the first observing night. Then, the TNG astronomer will introduce the Visitor to the instrument and to the telescope. At 1:00 UT the TNG Astronomer will go down to the Residencia. The TNG Astronomer may exceptionally be called during the rest of the observing run. A Telescope Operator is staying with the visitor along the entire observing run and shall be the first-aid person in case of need about instrumentation and observations.

As a general rule, any night when a TNG astronomer is present, the time preceding the nautical twilight will be devoted to the acquisition of sky flats, according to the TNG calibration plan, even if not related to the scheduled program.

For safety reasons, visiting astronomers are not authorized to remain alone at the TNG. Calibration frames should be taken in the evening. Under normal circumstances, all telescope and instrument activities terminate once the sky brightness becomes too high to carry out the scheduled scientific observations. The Visiting Astronomer shall thus leave the telescope together with the Telescope Operator, and go down together to the Residencia. The Telescope Operator is in charge of the security of the TNG during observing nights: he/she will decide unconditionally on the alert status due to bad weather or other circumstances. The Visiting Astronomer shall follow in this case his/her instructions. This includes the use the TNG visitor car.

Visitors are requested to carefully use all the common areas at the telescope, respect all the non-smoking signs, and strictly follow all the indications given by the support astronomers and/or telescope operators, in particular those concerning the closure of the telescope for meteorological or safety reasons.

In the control room area, a wireless connection is available, as well as an eduroam access point.

Please note that the targets listed here are protected for exclusive observation with Harps-N within the Harps-N Consortium.

Visitor Astronomers, when requested, will carry out authorized Target of Opportunity observations. Please read carefully our ToO policy.

For any inquiries on the use of the TNG facilities, please ask the support astronomer or the operator.

3. Technical info and hints

3.1 Instrument switchings

The exchange between instruments within the same Nasmyth focal station (DOLORES/HARPS-N) is practically immediate, while the change of Nasmyth station (e.g. switching from NICS to DOLORES) may take about 5-10 minutes. All the switchings can be repeated as many times as necessary, although we recommend to keep them at a minimum, to reduce overheads.

3.2 Spectroscopic observations with DOLORES and NICS

Centering object into the slit. The operation is quite fast for objects which are relatively bright, i.e. which are clearly visible on a short exposure (less than 60s) image. Direct centering on faint sources could take much longer and is not recommended. We invite all astronomers to accurately determine, well in advance of the observations, the positions of faint objects relative to nearby, brighter “pivot” sources. By aligning the slit along the object-pivot line, i.e. by rotating the instrument to a predetermined position angle, one can quickly center the pivot source in the slit and be sure that the target is also in the slit.If this method cannot be used, i.e. if the choice of the slit position angle is dictated by other constraints, one can take advantage of the reliable and accurate combined-offset of the TNG which usually guarantees sub-arcsec accuracy for blind offsets of several tens of arcsecs.

Calibration lamps. To avoid excessive overheads we invite all astronomers to make use, whenever possible, of the calibration data-base of the TNG or collect the calibration frames early in the afternoon. For those programs requiring a “normal” wavelength calibration (i.e. accurate to about 1 pixel) we suggest to take advantage, whenever possible, of the sky airglow emission lines to monitor instrumental drifts (if any). Observers aiming at very precise (less than 1 pixel) measurements of wavelengths on spectra of point sources (e.g. programs for measuring stellar radial velocities) should keep in mind that such an accuracy can be easily achieved using atmospheric absorption lines/bands to determine the sub-pixel shift in wavelength between the different spectra. The use of emission lines (either lamps or airglow) for this purpose is not recommended because the results might be hampered by the unavoidable non-uniformity of the slit illumination, especially in situations of good seeing.

3.3 Optical filters for DOLORES

All the optical filters available at TNG can be mounted on DOLORES. However, only the standard filters are regularly available. Since requests for filters change must be communicated at least 2 weeks before the observations, we invite all users to refer to the filter page which also contains instructions for those who intend to use private filters.

3.4 Multi-object spectroscopy with DOLORES

Please keep in mind that special instructions and time constraints apply to programs requiring multi object spectroscopy (DOLORES+MOS), see the dedicated web page.

4. After observing

4.1 Reports

At the end of their run, observers are expected to fill in our Observer Feedback Form. They are also kindly requested to fill in the ORM Residence Feedback Form.

4.2 Data delivery

Scientific data collected are automatically saved in the TNG archive and copied to the IA2 Archive facility where the astronomers can download their own data. Non-archived data (e.g. guide frames) can be provided on a best effort basis. Requests are to be addressed to the Head of Astronomy before the beginning of the observing run.

5. Publications based on data collected at the TNG

Please remember that any publication based on TNG data should be suitably acknowledged. A complete reference should be communicated by e-mail to Walter Boschin.