Note the comments. This single visit program has the same FOV as my program 11232. If it is scheduled immediately before that program, then a new guidestar acquisition can be avoided. ----- Attempting Submission 1 (Wed May 02 16:44:52 GMT 2007) ----- If this proposal is approved, it may be that the two orbits can be charged against John Biretta's Emission-Line Filter calibration program 11038. Assigned ID: 14 ----- Attempting Submission 2 (Wed Jan 17 11:23:20 CST 2007) ----- Phase I Proposal 14 (CalibrationOnly) successfully submitted. ----- Attempting Submission 3 (Wed Jan 17 12:04:37 CST 2007) ----- Phase I Proposal 14 (CalibrationOnly) successfully submitted. ----- Attempting Submission 4 (Wed Jan 17 12:06:41 CST 2007) ----- Calibration of the WFPC2 HeII and [SII] Filters. Observations of NGC 6720 (the Ring Nebula) will be used to determine the calibration constants for the important emission-line filters that isolate nebular HeII (F469N) and [SII] (F673N) emission. The pre-launch calibrations are inadequate because of possible temporal changes and the fact that these interference filters are used in a different configuration from that of the ground calibration. The Ring Nebula is a nearly ideal reference source as multiple 2.4"x4.0" samples have been accurately measured spectro-photometrically and five of the six samples can be imaged with one pointing of the HST. The method of derivation of the calibration constants will be the same as previously employed to calibrate the primary emission-line filters for the WFPC2 (F487N, F502N, F656N, F658N) and ACS (F502N, F658N, F660N) using the Orion Nebula as a reference source. However, Orion cannot be used for this calibration because the targeted lines are weak ([SII]) or absent (HeII) and the scattered-light continuum is strong. The Ring Nebula has strong HeII emission in its middle, strong [SII] emission in its main ring, and a weak (atomic only) continuum.
We will make WFPC2 observations of the Ring Nebula (NGC 6720) in the F469N, F547M, and F673N filters for the purpose of calibrating the F469N and F673N filters. ISM AND CIRCUMSTELLAR MATTER 0 true 0.0 false false false false false false SUPPORTED ISM EMISSION LINE NEBULA PLANETARY NEBULA RING-NEBULA J2000 18 53 35.5400 +33 01 48.00 J2000 WFPC2 Imaging No F469N WFPC2 Imaging No F547M WFPC2 Imaging No F673N /private/tmp/OPVisit24501.xml This visit uses the same target and orientation as the PI's Visit 1 of program 11232 and optimally would be executed immediately before Visit 1 of program 11232. If that is done, then the exposure times of 11232 should be increased to take advantage of not having to do a new guidestar acquisition. (Tic-Visit :proposal-id 11231 :visit-id "01" :proposal-version -1 :trans-version "20070325" :date "02-May-2007 11:29:53.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 403344 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11231 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11231 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2520 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3152 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11231 :visit-id "01" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2520 :al-overhead-at-end 180 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3152 :pcs-gap 0 ) true 2 0