Exposure Time Calculators

NOAO, in a collaborative effort with CTIO and KPNO, now supports two exposure time calculators for assisting investigators in preparing their observing proposals. Both are IRAF tasks available through a Web-interface.

• During the last observing proposal period the ccdtime interface at http://www.noao.edu/scope/ccdtime/ was used by most investigators (based on the number of hits) to estimate exposure times for CCD and IR imaging requests.

• A new tool called spectime for computing exposure times for all spectroscopic instruments at NOAO is available at http://www.noao.edu/scope/spectime/. Spectime, written by Frank Valdes, is an IRAF adaptation of the exposure time calculator which has been available for some of the spectroscopic instruments at CTIO for the last few years.

All proposers are encouraged to use these tools for estimating the number of nights for each run on the front page of the proposal form and for their technical justifications on the run details pages.

Many scientific staff members have contributed input into these tasks including comments, suggestions, testing, calibration files, etc., and we are grateful for their involvement.

Kitt Peak maintains two additional tools as an aid to investigators to identify imaging or spectroscopic needs and exposure times:

http://www.noao.edu/kpno/imaging/imaging.html
identify a telescope/instrument configuration from input requirements;

http://www.noao.edu/kpno/spectroscopy/spect.html
predict a telescope/spectrograph combination based on input parameters.

Also see the CTIO home page (http://www.ctio.noao.edu/) and KPNO home page (http://www.noao.edu/kpno/) for additional information.

Todd Boroson, Jeannette Barnes