Phase 1: Application & Science Definition

Introduction

The LT is available to UK and international astronomers for scientific research. It is, however, also available to students from schools and colleges in the UK and Ireland for educational purposes — see The Schools' Observatory website for details. A small amount of time is also available to amateur and semi-professional astronomers through our PATAG programme.

To which TAG do I propose?

This is determined by the affiliation of the proposal's Principal Investigator (PI):

• A PI from a UK institute must apply through STFC's Panel for the Allocation of Telescope Time (PATT). See Applying through PATT below.
• A PI from a Spanish institute must apply through CAT, using the standard CAT form and submission procedure administered by the IAC.
• A PI from a non-UK and non-Spanish institution may apply through the OPTICON Transnational Access programme, or through the International Scientific Committee (CCI). Non-UK PIs not eligible for CAT, OPTICON or CCI time may apply through PATT.
• PIs from the LJMU Astrophysics Research Institute may apply via the internal JMU TAG. JMU will also consider proposals with a non-JMU PI under certain conditions (see below).

When do I apply?

All prospective PIs must wait until their Telescope Allocation Group (TAG) issues a Call for Proposals for the upcoming semester. The Call gives all relevant details (application procedures, current telescope performance, instruments available, etc.) and usually sets a deadline of 3–4 weeks from the date of issue.

We use a "twice-yearly / 8-month semester" model with a two-month overlap at the end of each semester. Between 1 January and 28/29 February, proposals from outgoing semester B and incoming semester A remain in the queue; the same applies between 1 July and 31 August. The goal is to avoid empty queue time and maximise the chances of top-ranked proposals being completed. So targets observable in January/February may be requested in a semester A or B proposal (the same applies to July/August).

How much time is available?

The available clear time on the LT is distributed as follows (last updated August 2014):

Typically of order 1000 hours is available for allocation by all TAGs combined to proposals ranked A or B; roughly 300 hours is also awarded as backup time to a number of rank C proposals. The exact amount is listed in the Call for Proposals.

What kind of time should I apply for?

There are five timing constraints which control when and how often your targets are observed:

FLEXIBLE

Observations can be carried out at any time during the semester when conditions are appropriate.

MONITOR

Observations of an object are required at a regular interval.

INTERVAL

Observations taken as often as possible, provided the interval between them is never less than specified.

PHASED

Observe a target at a particular phase of its periodic cycle (e.g. an eclipsing binary during eclipse, on any orbit during the semester).

FIXED

Observations only carried out at a specified time, or not at all (e.g. occultations or simultaneity with another facility). FIXED time is very intrusive — the telescope overrides all other groups to secure the data — so a clear need for FIXED status must be demonstrated (a transit should be scheduled as PHASED). No more than 20% of any panel's awarded time should be FIXED.

Deciding between these can be tricky and they are not commonly used at other observatories — it is important to get this right when preparing observations in Phase 2. Please don't hesitate to contact us with questions.

What observing conditions should I apply for?

To allow efficient flexible scheduling, PIs must specify the seeing and photometric conditions needed, and should indicate the sky-brightness limitations of their project. This information may be used by each TAG when allocating time.

Sky brightness

The LT sky-brightness model predicts a relative sky brightness (in magnitudes brighter than the best-case, true-dark sky), including contributions from solar position, lunar elevation, lunar phase and lunar separation from pointing. The same value might derive from a faint twilight sky, a crescent Moon, or a gibbous Moon low on the horizon — the telescope makes no distinction between these.

Seeing

Scheduling uses the most recent seeing estimate, based on real-time reductions of recently-taken images. All proposals must include an estimate of the worst seeing (in arcseconds) under which observations would be possible.

Photometric conditions

All proposals must specify whether photometric conditions are needed, or whether non-photometric conditions are acceptable. In Phase 2, if a weather constraint is set to non-photometric, observations will only run in non-photometric conditions; if both are acceptable, a transparency constraint should not be set.

If photometric time is awarded and groups are flagged as needing photometric, we endeavour to observe them only under photometric conditions. Note that each night is defined as photometric or non-photometric at its start by the Duty Officer, and the robotic control system cannot distinguish photometric from mildly non-photometric conditions during the night — so some photometric groups may be observed in mildly non-photometric conditions.

Which instruments are available?

It is extremely important that prospective users always refer to the latest Call for Proposals for the instruments available in any given semester. For shared-risk or non-facility-class instruments, proposers should contact LT Phase 1 Support to discuss feasibility and any collaboration arrangements before applying. See the instrument overview for descriptions.

Pointing and tracking

Please see the current Call for Proposals, or contact LT Phase 1 Support, for up-to-date information on the pointing and tracking capabilities of the LT.

How do I calculate how much time I need?

Use the instrument-specific exposure time calculator to determine the exposure time (T_e) needed. Begin each calculation with a single group initialisation overhead T_i of 20 seconds, then add the instrument-specific overheads below.

IO:O overheads

To the exposure time (T_e) and initialisation time (T_i), add:

• Acquisition (slew on target), T_a = 60 s
• Autoguider acquisition, T_g = 45 s (only if you nominate the autoguider)
• Filter change, T_f = 15 s
• Readout, T_r ≈ 18.5 s for 2×2 on-chip binning (includes 5 s at the start of each exposure for FITS-header information)

LIRIC overheads

Please review the LIRIC instrument page for overheads. Exposure times can be worked out using the exposure calculator with the instrument field set to IO:I for the moment.

MOPTOP overheads

MOPTOP operates comparably to IO:O except with essentially zero read-out overhead. Include overheads for initialisation (T_i = 20 s), slew (T_a = 60 s), filter change (T_f = 10 s, at least once per group), and optionally the autoguider (T_g = 45 s); readout T_r = 0 s.

MOPTOP exposure time is the "duration" — the interval between the start of the first frame and the end of the last — distinct from the individual frames made at 16 per rotation. In "fast" mode the rotation period P = 8 s and frame exposure t_e = 0.4 s; in "slow" mode P = 80 s and t_e = 4.0 s. The duration is rounded up to a whole number of rotations.

FRODOSpec overheads

• Initialisation (T_i): 20 s
• Acquisition (slew plus moving the target onto the fibre bundle): 4 minutes
• Each readout: 20 s
• Grating change: 20 s
• Xenon arc exposure (recommended for wavelength calibration): 60 s
• Tungsten lamp exposure (recommended for fibre tracing): 60 s

SPRAT overheads

Please review the SPRAT instrument page for details on overheads with this instrument.

RISE overheads

No filter-change or readout overheads apply to RISE — only a 60 s slew overhead and the universal 20 s initialisation overhead are required. No filter changes are possible and the readout time is negligible.

Multi-instrument groups

Overheads incurred while changing from one instrument to another are set at 60 seconds.

Minimum Usable Fraction

In addition to total time requested, proposers must specify a Minimum Usable Fraction (MUF) of data that is acceptable. This helps the technical team schedule effectively — e.g. whether to finish one programme or start another that may not complete.

Specify the MUF in the technical case of your proposal. For example, MUF = 5% means "any observations would be usable", while MUF = 90% means "a complete or nearly complete sample is essential". The TAC reserves the right to revise the MUF of successful proposals if appropriate.

Our policy on group length & repetition of long groups

Broadly, the robotic LT caters for three classes of observation:

• Rapidly fading transients (e.g. GRBs) requiring an immediate response.
• Monitoring of variables and transients with short groups repeated every few hours, days or weeks (e.g. novae, SNe).
• Monitoring with a single (or a few) long groups (e.g. planetary or binary transients).

The scheduler must accommodate all of these, often on the same night. Response to a GRB can interrupt the current observation, but such transients fade rapidly and the interrupted group can usually be repeated within tens of minutes. Long groups can be far more intrusive, especially if repeated on consecutive nights.

We do not limit the length of individual groups, nor the interval between repeats. However, proposals requesting multiple long groups must be accompanied by a very strong science case, and the need for repeating such groups within a few days should be clearly demonstrated. TAGs are encouraged to bear this in mind when allocating time to poorly-ranked proposals likely to occupy more than 50% of a typical 8–10 hour night.

Other restrictions and guidance notes

We endeavour to obtain all data requested for allocated programmes. However, on any given night a dozen or more astronomers effectively share a single telescope. Compromises may be necessary, and LT operations staff reserve the right to remove from the scheduler any observations that seriously interfere with other programmes. If you anticipate such problems, we strongly recommend contacting the LT in advance and/or addressing the issue in your technical case.

What happens if my application is successful?

PIs of successful proposals must prepare their observations before the start of the semester using the LT Phase 2 GUI. Proposers seeking to observe Targets of Opportunity may submit groups shortly after the ToO is triggered, though user support may not be immediately available (particularly during holidays and weekends). Users are encouraged to be prepared at the start of the semester and generate their groups early.

How do I get help?

Help with technical queries (running the exposure time calculator, editing the proposal form, submission, etc.) is available from LT Phase 1 Support at ltphase1@ljmu.ac.uk. More general queries may be sent to the LT support group — please refer to the LT web pages first.

Applying through PATT & JMU

JMU and PATT proposals are submitted via our online interface. Click Submit a Proposal and follow the instructions — you will need to register an account if you don't have one. Queries with this system should be addressed to ltphase1@ljmu.ac.uk.

PATT proposal expiry policy

Proposals requesting time across multiple semesters are usually welcome (see the Call for Proposals). A proposal will expire at the end of the semester unless time has been specifically allocated in multiple semesters. If a proposal has not been awarded time in future semesters, you must reapply to continue that project.

Non-JMU PIs applying for JMU-allocated time

The ARI Management Board wishes to avoid JMU staff being used as "front-PIs" for non-JMU-led projects. JMU time may support non-JMU-led proposals provided:

• The PI has a strong connection with JMU — a former JMU student or member of staff who left less than 1 year ago, or a visiting fellow with an agreement specifically providing for their use of the LT.
• The proposal includes at least one active co-I currently employed by JMU, with good knowledge of the science area or heavy involvement in data reduction/analysis, who will be a co-author on any resulting publications.

No more than 25% of the available JMU time (when over-subscribed) shall be awarded to non-JMU-led proposals.

Southampton & FRODOSpec: the University of Southampton's contribution to FRODOSpec fulfils the requirement of a strong connection with JMU. FRODOSpec proposals led by a Southampton PI will be accepted by the JMU TAG (subject to the 25% rule). Collaboration with LJMU staff as co-Is is encouraged but not mandatory.

Applying through CAT

Applicants for CAT time (PIs based at Spanish institutions) should refer to the procedures at, and download the normal CAT form from, the CAT pages at the IAC.

Applying through CCI

The International Scientific Committee (CCI) of the Roque de los Muchachos (ORM, La Palma) and Teide (OT, Tenerife) observatories regularly invites applications for International Time Programmes (ITP). The aim is to encourage international projects that cannot easily be accommodated by other TAGs and that foster collaboration between the user institutions of the La Palma observatories.

Proposals that benefit from more than one facility are especially encouraged. CCI time is only available to PIs from signatory countries (Spain, Germany, UK, Italy, France, Belgium and Finland); proposals should include co-Is from at least three signatory countries. Refer to the CCI page at the IAC (where CCI time is referred to as "5% international time").

Applying through Opticon

Applicants from non-UK and non-Spanish European institutions may apply for LT time through the OPTICON Trans-national Access programme. OPTICON rules state that the PI and at least half of the co-Is must be working at institutions from EU member states or EU-associated countries outside the country that owns the telescope (in this case, the UK).