Small Telescopes at Cerro Tololo

Index

Background

Four of the smaller telescopes on Cerro Tololo are now being operated by the SMARTS consortium, a group of several universities and other organizations. SMARTS is headed by Prof. Charles Bailyn at Yale, and NOAO is a member.

The SMARTS CONSORTIUM WWW SITE is the master source for the small telescopes' schedules, and has much other useful information as well. What follows is a summary primarily for NOAO Users of the SMARTS telescopes; the SMARTS site should be used in preference where there is a discrepancy.

NOAO Observing on SMARTS Telescopes

The NOAO community (that is, anyone eligible to apply for time on any NOAO telescope) may apply for time on the SMARTS-run telescopes, through the standard NOAO proposal process. NOAO users are assigned approximately one-fourth of the total available time, averaged over all telescopes.

Back to Top

Telescopes and Instruments

News and Instrument Upgrades

The 1.3m/ANDICAM now has neutral-density filters installed for viewing bright sources in V, I, H, and narrowband He 1038nm. Tests with standard stars show that the V+ND combination has an attenuation of 4.6 (a factor of 39,000, or 11.5 magnitudes) over that of the V filter, and the I+ND combination an attentuation of 3.0 (1100, or 7.6 magnitudes).

The 1.0m now has the 4K optical imager with full UBVRI and SDSS filter wheel. It has field of 20 arc minutes and good sensitivity in U and B; see the Y4KCam web page for details.

Back to Top

The Process of Applying and Observing

1. Choose the telescope and instrument combination from the table above, paying attention to projected changes over the semester and to availablity. Especially note that an instrument provided by another consortium member may be dedicated mostly or entirely to a specific project, leaving little or no time for other users.
   • Precision photometry is best carried out on the 0.9m or 1.0m, since the queue-mode of the 1.3m does not lend itself to observations of comparison stars beyond a basic nightly calibration.
   • Wide-field imaging will be best done by the 1.0m with the 4K imager.
   • Precision astrometry has benefited from the stability of the 0.9m instrument.
   • Narrow-band and unusual filters from the CTIO collection are most easily accomodated on the 0.9m.
   • Note that changes of grating and filter are difficult to arrange for the 1.5m spectrograph during the night, though they can be accomplished without much trouble by the daytime staff. This means that projects which do not take up a complete night will have to share the setup with other projects, and the optimum configuration may not be available. Proposers should note alternate filter and grating configurations which they could use if the primary choice is not possible.
   • The ANDICAM on the 1.3m takes simultaneous optical and infrared data, so projects for which this is necessary or useful should specify this telescope. Conversely, projects which use only the optical side of the instrument require the IR side to be idle, and should probably go to the 0.9m or 1.0m.
   
   
2. Choose the observing mode and required time using estimates of exposure time, period coverage, number of targets, etc.
   • Note that there are no telescope operators during classical observing runs on SMARTS telescopes. Mountain personnel will install your requested set-up in the afternoon and get you started operating the telescope in the beginning of the evening. If trouble occurs late at night, a limited amount of assistance can be called in, subject to aperture priority (which means that the 4m will be attended to first if it has trouble). We strongly suggest that new observers, at least, arrive on the mountain a night early to familiarize themselves with the telescope, and if possible be accompanied by a veteran.
   • Synoptic observations, which require only a limited time per night but should be carried out over a long period of time (for example, monitoring a variable star with a period of hundreds of days), are best done on the 1.3m.
   • Imaging/photometry programs which require observer intervention, or for other reasons should be done in classical (visiting-astronomer) mode, should be carried out on the 0.9 or 1.0.
   • Programs which are most conveniently done in service mode can be done on all telescopas except the 1.0m must be noted as such in the observing proposal, since it is difficult and may be impossible to convert classical time to service time once the schedule is completed. In addition, detailed procedures for carrying out your service observations must be given to the observer; see the specific SMARTS web page.
   • As noted above, spectroscopic programs in service mode have a restricted range of setups available. This is because several programs will be done during a night, and the setup will not normally be changed during the night. See the SMARTS 1.5m web page for details.
   • There is no Director's Discretionary time as such on SMARTS telescopes. However, most semesters there is some time not given over to primary-priority programs. Emergent requests for this time may be submitted in accordance with the CTIO DD time policy. Requests supported by the CTIO Director are forwarded to the SMARTS schedulers as a secondary-time project. Note that a favorable decision by the CTIO Director does not automatically result in time awarded, since secondary-time programs from other consortium institutions must be considered.
   • The Target of Opportunity procedures for SMARTS telescopes differ from general NOAO rules in detail, and in general are only carried out during queue observing:
     
     • The queue gets sent down at 4pm on weekdays and 2pm on weekends (Chilean time). ToOs that are called in before then (by e-mail to the queue scheduler for the telescope involved) will be scheduled along with the rest of the queue. After that, the scheduler can try to fit in the observations, but it is not guaranteed.
     • Observers should NOT communicate with the mountain directly!
     • If faster response than this is required for scientific reasons, we can set up procedures in advance to make this happen. BUT any such arrangement must be cleared with the queue schedulers BEFOREHAND.
     • ToOs are executed according to the same priorities as the overall scheduling process. Therefore, ToOs should be requested along with other programs, and prioritized in the same way. ToOs will ONLY be executed if they do not conflict with higher-ranked standard proposals. While many standard proposals are flexible, and thus can be moved to accommodate lower-ranked ToOs, some are not, so ToOs that are "must do" projects should be ranked very high.
   
   
3. When granted time,
   • communicate with the telescope schedulers noted on the SMARTS website. It is best to get in touch well ahead of your run, so that everyone understands the procedures and special requirements. Keep in mind that telescope schedulers are carrying out the task on a part-time basis, and may not be as responsive as a dedicated operations crew.
   • While every reasonable effort will be made to schedule the telescope, instrument and setup you request, it is not always possible to do so. In particular, there has been a heavy demand for synoptic imaging, more than the 1.3m could possibly handle. In preference to rejecting good proposals entirely, they may be assigned time on a telescope or instrument other than those requested. If it is not possible to carry out your program as scheduled, please contact the SMARTS schedulers as soon as you can. If it is still possible, but less useful or convenient, please be aware that it's probably the best we can do, keeping in mind all the other demands on the system.
   • If you are coming to Tololo in person, be sure to fill out the Travel Information Questionnaire and the Visitor Support Questionnaire so that the CTIO travel and mountain personnel know you're coming, and what you need. The latter has now been updated to reflect the 1.0m. You should also review the details of ccd operations for ARCON telescopes; the 1.0m uses a different system, Prospero, for which see the 4K optical imager web pages.


4. Repatriation of your data will depend on your observing mode. For classical observing the methods mentioned on the CTIO web site apply: DAT or Exabyte tapes (or even downloading into your laptop!). For service observing, your data will be available via ftp from the US telescope website, using procedures which will be communicated to you.

Back to Top

last updated 14 March 2008
 

CTIO  >  SMARTS (Small Telescopes at Cerro Tololo)