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Hubble Space Telescope
WF/PC-1 Photometric Monitoring Results

WF2 and PC6 observations of the photometric standard star BD+75D3255 have been taken monthly since May 1991 for photometric monitoring of the WF/PC. This memo contains the results of this program through November 17, 1993. All filters below F785LP show decay in throughput sensitivity which has been restored periodically by scheduled (and unscheduled) decontaminations.

Decontamination Dates:

    08 May 1991
    05 July 1991
    03 February 1992
    04 February 1992
    03 March 1992
    08 March 1992
    07 August 1992
    02 August 1993
    

Aperture photometry was done using a radius of 30 pixels for WF2 and 60 pixels for PC6. The data below are of count rates normalized to the 05 February 1992 count rate. The data on this date was taken only 1 day after a decontamination when the instrument was clean. The exception is the WF F230W data which is normalized to the 10 August 1992 count rate.

The last published instrument science report on this subject was "WF/PC Photometric Monitoring Results" WF/PC ISR 93-02 by Ritchie and MacKenty written on February 04, 1993. Copies of this report may be obtained from help@stsci.edu.

NOTE: Please note that there was a mistake in the instrument science report and earlier Web postings on for WF F284W. A star that was saturated was mistakenly used for the normalization. W0V00403T had 3 saturated pixels. The count rates for W0V00402T have now been used instead. Changes are of the order of 1%. Thanks goes to Mike Wolff for noticing this problem.

See also: Contamination Correction in SYNPHOT for WFPC2 and WF/PC-1 (HTML, or PDF).

The columns below are:

  
    Normalized Count Rate,  Error,  MJD date.
    
    ------------------------------------------------------------
    WF F194W
	 0.09497297       0.0047664        48399.75
	 0.02975774     0.004649876        48427.92
	  0.1867239     0.004866724        48453.69
	 0.03708515     0.005421991        48484.26
	0.009682778     0.004186995        48512.22
		 0.           INDEF        48536.95
		 0.           INDEF        48564.65
		 0.           INDEF        48592.91
		 0.           INDEF        48623.28
		 0.           INDEF          48652.
		 1.       0.0043819        48657.09
	  0.1636817     0.003844775        48662.32
		 0.           INDEF        48678.13
		 0.           INDEF         48704.1
		 0.           INDEF        48732.08
		 0.           INDEF        48760.11
		 0.           INDEF        48789.97
		 0.           INDEF        48816.79
		 0.           INDEF        48844.09
		 0.           INDEF        48872.05
		 0.           INDEF        48906.71
		 0.           INDEF        48930.53
		 0.           INDEF         48958.7
		 0.           INDEF        48985.64
		 0.           INDEF        49016.15
		 0.           INDEF        49040.42
		 0.           INDEF        49068.12
		 0.           INDEF        49122.21
		 0.           INDEF        49144.54
	  0.3426099     0.004258124        49203.77
		 0.           INDEF        49212.06
		 0.           INDEF        49237.68
		 0.           INDEF        49255.12
		 0.           INDEF         49282.8
		 0.           INDEF        49308.73
    ------------------------------------------------------------
    WF F230W
	  0.4630203     0.002473116        48399.75
	  0.2039858     0.002109903        48427.92
	   0.621155     0.002632333        48453.69
	   0.237684      0.00201083        48484.26
	 0.08279422     0.001785119        48512.22
	 0.04541507      0.00169195        48536.95
	 0.02432204     0.001628741        48564.65
	 0.01386756     0.001579062        48592.91
	 0.00938426     0.001565886        48623.28
	0.003200369     4.249649E-4          48652.
		 0.           INDEF        48657.09
		 0.           INDEF        48662.32
	  0.3194479     0.001882731        48678.13
	   0.519039     0.002250081         48704.1
	  0.1633804     0.001751709        48732.08
	 0.07798301     0.001651687        48760.11
	 0.03486583     0.001588397        48789.97
	 0.02282443     0.001581936        48816.79
		 1.     0.002165015        48844.09
	  0.3259868     0.001900096        48872.05
	  0.1409938     0.001666653        48906.71
	 0.08970156      0.00164272        48930.53
	 0.05571857     0.001594504         48958.7
	 0.03677901     0.001564878        48985.64
	 0.02352881     0.001558386        49016.15
	 0.01860373     0.001538474        49040.42
	 0.01187955     0.001529283        49068.12
	0.006982324     0.001540288        49122.21
	0.006911941      0.00154671        49144.54
	  0.8024168     0.005945918        49203.77
	  0.4759924     0.002122452        49212.06
	  0.2161723     0.001705523        49237.68
	  0.1472313     0.001621308        49255.12
	 0.09401562     0.001561992         49282.8
	 0.06950243     0.001543093        49308.73
    ------------------------------------------------------------
    WF F284W
	  0.2970298     0.003103914        48536.95
	  0.2491151     0.002926333        48564.65
	  0.2175705      0.00282855        48592.91
	  0.1939099     0.002754126        48623.28
	  0.1752266     0.002688627          48652.
		 1.     0.003318229        48657.16
	  0.7855973     0.002939384        48662.33
	  0.6409144     0.003660076        48678.13
	  0.7426771     0.003980355         48704.1
	  0.4587753     0.003355171        48732.08
	    0.33358     0.003103362        48760.11
	  0.2327019     0.002811616        48789.97
	   0.206063     0.002776529        48816.79
	  0.9264031     0.004443943        48844.09
	  0.6522289     0.003718272        48872.05
	   0.459198     0.003273532        48906.71
	  0.3826485     0.003090904        48930.53
	  0.3203318     0.002949877         48958.7
	  0.2884032     0.002914247        48985.64
	  0.2425493     0.002850749        49016.15
	  0.2238721     0.002800159        49040.42
	  0.2077782     0.002769723        49068.12
	  0.1745822      0.00273421        49122.21
	  0.1639834     0.002741375        49144.54
	  0.8566433      0.00422299        49203.79
	  0.7271098     0.003893062        49212.06
	  0.5316184     0.003311196        49237.68
	  0.4533149     0.003137314        49255.12
	  0.3794897     0.002972211         49282.8
	  0.3410358     0.002910977        49308.73
    ------------------------------------------------------------
    WF F336W
	   1.001844      0.00380988        48399.75
	  0.9664959     0.003716019        48427.92
	  0.9972407      0.00373996        48453.69
	  0.9229963      0.00354681        48484.26
	  0.7848741     0.003195322        48512.22
	  0.7059923     0.002985827        48536.95
	  0.6649669     0.002867467        48564.65
	  0.6379696     0.002781872        48592.91
	  0.6217274     0.002739653        48623.28
	  0.5893862     0.002657583          48652.
		 1.     0.002494198        48657.09
	  0.9392906     0.003377567        48678.13
	  0.9611695     0.003458465         48704.1
	  0.8165824     0.003179476        48732.08
	  0.7008095     0.003255261        48760.11
	   0.606457      0.00304224        48789.97
	  0.5628595     0.002976169        48816.79
	   0.970957     0.003733753        48844.09
	   0.915377     0.003611885        48872.05
	  0.8256576     0.003436236        48906.71
	  0.7855973     0.003381995        48930.53
	  0.7419933     0.003301315         48958.7
	  0.6969474     0.003194133        48985.64
	  0.6686518      0.00313971        49016.15
	  0.6426877     0.003080131        49040.42
	  0.6367955     0.003077877        49068.12
	   0.591017     0.002999097        49122.21
	  0.5818352     0.002974427        49144.54
	  0.9221467     0.003611356        49212.06
	  0.8487895     0.003418859        49237.68
	   0.793597      0.00332191        49255.12
	  0.7670082     0.003266214         49282.8
	  0.7351907     0.003217331        49308.73
    ------------------------------------------------------------
    WF F439W
	   1.010183     0.005245415        48399.75
	  0.9954054      0.00516355        48427.92
	  0.9890084     0.005064794        48453.69
	  0.9611695     0.004868851        48484.26
	  0.9196022     0.004671559        48512.22
	  0.8798325     0.004527546        48536.95
	   0.853493     0.004396112        48564.65
	  0.8371437      0.00430691        48592.91
	  0.8241381     0.004246931        48623.28
	  0.8098415     0.004194489          48652.
		 1.      0.00332413        48657.09
	  0.9745408     0.004649841        48678.13
	  0.9682778     0.004687295         48704.1
	  0.9204496     0.004596319        48732.08
	  0.8629785     0.004437696        48760.11
	   0.799466     0.004172917        48789.97
	  0.7684224     0.004122964        48816.79
	  0.9691701     0.004639738        48844.09
	  0.9453661      0.00457436        48872.05
	  0.9170648     0.004494723        48906.71
	  0.8879735     0.004404115        48930.53
	   0.876597      0.00437905         48958.7
	   0.851138     0.004322947        48985.64
	  0.8480081      0.00432499        49016.15
	  0.8256577     0.004246809        49040.42
	  0.8340652     0.004281487        49068.12
	  0.8038962     0.004208785        49122.21
	  0.8076069     0.004227016        49144.54
	  0.9392906     0.004541695        49212.06
	  0.8986695     0.004338403        49237.68
	  0.8838937     0.004319287        49255.12
	  0.8733734     0.004288742         49282.8
	  0.8637738     0.004273165        49308.73
    ------------------------------------------------------------
    WF F555W
	  0.9808441     0.004725193        48399.75
	  0.9629417     0.004750717        48427.92
	  0.9862795     0.004705212        48453.69
	  0.9781377     0.004610593        48484.26
	  0.9727473       0.0045396        48512.22
	  0.9204496     0.004312766        48536.95
	  0.8961899     0.004206352        48564.65
	  0.8814548     0.004108384        48592.91
	  0.8677607     0.004041388        48623.28
	  0.8511381     0.004006183          48652.
		 1.      0.00311076        48657.09
	   0.957635      0.00428083        48678.13
	  0.9594006     0.004307122         48704.1
	  0.9306792     0.004292914        48732.08
	  0.9061499     0.004194972        48760.11
	  0.8838936     0.004125718        48789.97
	  0.8582227     0.004046972        48816.79
	  0.9691701     0.004310783        48844.09
	  0.9427575     0.004241873        48872.05
	  0.9281111     0.004201953        48906.71
	  0.9289664     0.004233425        48930.53
	  0.9187557     0.004207202         48958.7
	  0.8896107     0.004112598        48985.64
	  0.8782133     0.004079367        49016.15
	  0.8725694     0.004062547        49040.42
	  0.8605974     0.004041003        49068.12
	  0.8464475     0.004000179        49122.21
	  0.8550667      0.00402581        49144.54
	  0.9281111     0.004196965        49212.06
	  0.9306792     0.004155093        49237.68
	  0.9187557     0.004133441        49255.12
	  0.9094943     0.004101152         49282.8
	  0.9011561     0.004093991        49308.73
    ------------------------------------------------------------
    WF F785LP
	   1.041358     0.007319114        48399.75
	   1.020469     0.007497796        48427.92
	   1.004616     0.007200691        48453.69
	   1.028016     0.007164427        48484.26
	    1.01953      0.00700305        48512.22
	   1.020469     0.006969536        48536.95
	   1.012046     0.006785081        48564.65
	   1.005542     0.006697925        48592.91
	   1.000921     0.006609546        48623.28
	  0.9935735      0.00655405          48652.
		 1.     0.004695149        48657.09
	   1.008324     0.006640856        48678.13
	   1.017654     0.006741003         48704.1
	   1.016717     0.006832709        48732.08
	   1.015781     0.006757609        48760.11
	   1.003691      0.00661186        48789.97
	  0.9890084     0.006551481        48816.79
	  0.9972407     0.006614846        48844.09
	   1.006468     0.006651058        48872.05
	   1.006468     0.006641042        48906.71
	  0.9899198     0.006560621        48930.53
	  0.9954054     0.006579321         48958.7
	   1.006468     0.006672611        48985.64
	   1.000921     0.006646741        49016.15
	  0.9835581     0.006548043        49040.42
	  0.9917449     0.006594422        49068.12
	   1.002767     0.006637133        49122.21
	  0.9935735     0.006615552        49144.54
	  0.9745408     0.006515202        49212.06
	  0.9727473     0.006345933        49237.68
	  0.9826526     0.006401841        49255.12
	  0.9763376     0.006370719         49282.8
	  0.9853715     0.006423714        49308.73
    ------------------------------------------------------------
    PC F194W
	  0.1728224      0.01635036        48399.82
	 0.02290868     0.002985504        48428.05
	  0.3019952      0.02270017        48453.75
	 0.04466836     0.008449927        48500.62
	 0.03308263      0.00830863        48512.36
		 0.           INDEF        48536.82
		 0.           INDEF        48564.72
		 0.           INDEF        48593.05
		 0.           INDEF        48623.35
		 0.           INDEF         48652.8
		 1.      0.06985441        48657.23
	  0.2666859      0.02122624        48662.39
		 0.           INDEF        48677.66
		 0.           INDEF        48704.16
		 0.           INDEF        48732.15
		 0.           INDEF        48760.18
		 0.           INDEF        48790.03
		 0.           INDEF        48817.46
		 0.           INDEF        48844.16
		 0.           INDEF        48872.12
		 0.           INDEF        48906.78
		 0.           INDEF        48930.59
		 0.           INDEF        48958.76
		 0.           INDEF        48985.71
		 0.           INDEF        49016.21
		 0.           INDEF        49040.48
		 0.           INDEF        49068.18
		 0.           INDEF        49122.27
		 0.           INDEF         49144.6
	  0.4830588      0.03515797        49203.71
		 0.           INDEF        49212.13
		 0.           INDEF        49237.74
		 0.           INDEF        49255.18
		 0.           INDEF        49282.87
		 0.           INDEF        49308.79
    ------------------------------------------------------------
    PC F230W
	   0.455827      0.01003399        48399.82
	  0.1917785     0.005201531        48428.05
	  0.6154602      0.01233484        48453.75
	  0.1776642      0.00482347        48500.62
	  0.1348963     0.004116014        48512.36
	 0.07819878     0.003268649        48536.82
	 0.05195173     0.002664014        48564.72
	 0.03372873     0.002416674        48593.05
	 0.03156458     0.002447409        48623.35
	0.006594776     0.001098427         48652.8
		 1.      0.01923394        48657.23
	  0.5975854      0.01176033        48662.39
	  0.3617429     0.007348824        48677.66
	  0.5219153      0.01038289        48704.16
	  0.2208005     0.004930029        48732.15
	  0.1285879     0.003492615        48760.18
	 0.06655797     0.002690201        48790.03
	 0.05223962      0.00251612        48817.46
	  0.8511381      0.01655632        48844.16
	  0.3715352     0.007528777        48872.12
	  0.1944464     0.004412027        48906.78
	  0.1341529     0.003506965        48930.59
	 0.09436262     0.003002534        48958.76
	 0.07848742     0.002767917        48985.71
	 0.05375266     0.002546572        49016.21
	 0.04164856     0.002445046        49040.48
	  0.0383354     0.002434989        49068.18
	 0.01851825     0.002336433        49122.27
	 0.01789781     0.002354034         49144.6
	   0.742677       0.0145027        49203.71
	  0.4458615     0.008900728        49212.13
	  0.2228435      0.00483954        49237.74
	  0.1530383     0.003700546        49255.18
	  0.1083428      0.00305426        49282.87
	 0.08503545     0.002780057        49308.79
    ------------------------------------------------------------
    PC F284W
	   0.388687     0.006045498        48536.82
	  0.3429256     0.005065552        48564.72
	  0.3084608     0.004823032        48593.05
	  0.2962102     0.004844068        48623.35
	  0.2516518     0.004396799         48652.8
		 1.     0.006699736        48657.37
	  0.8417826     0.008667367        48662.41
	   0.709251     0.006449081        48677.66
	  0.7928664     0.006965605        48704.16
	  0.5607896     0.005976306        48732.15
	  0.4265795     0.005420382        48760.18
	  0.3296097     0.004732835        48790.03
	  0.3031098     0.004713741        48817.46
	  0.8806432     0.007373119        48844.16
	  0.6982324      0.00636003        48872.12
	  0.5485295     0.005665492        48906.78
	  0.4795126     0.005260826        48930.59
	  0.4168695     0.005049047        48958.76
	  0.3767038      0.00499193        48985.71
	  0.3241903     0.004836773        49016.21
	   0.311889     0.004794664        49040.48
	  0.2934945     0.004731117        49068.18
	  0.2436688      0.00458853        49122.27
	  0.2346389     0.004572942         49144.6
	  0.8822669     0.008799054        49203.72
	  0.7151546     0.006468046        49212.13
	  0.5440013     0.005336891        49237.74
	  0.4596212     0.005018847        49255.18
	  0.3995765     0.004791415        49282.87
	  0.3624099     0.004629154        49308.79
    ------------------------------------------------------------
    PC F336W
	  0.9611696      0.00705477        48399.82
	  0.8757901     0.005603418        48428.05
	   0.970957      0.00585267        48453.75
	  0.8653663     0.005344862        48500.62
	  0.8248975     0.005271765        48512.36
	   0.755788     0.004702625        48536.82
	  0.7304659     0.004163133        48564.72
	  0.7118688     0.004033235        48593.05
	  0.6995198     0.004041427        48623.35
	  0.6823387      0.00396623         48652.8
		 1.     0.003392851        48657.23
	  0.8928942     0.004441645        48677.66
	  0.9246982     0.004715156        48704.16
	  0.8256576     0.004459274        48732.15
	  0.7502397     0.004248532        48760.18
	   0.676083     0.004012925        48790.03
	  0.6415049     0.003851544        48817.46
	  0.9255503     0.004525471        48844.16
	  0.8782133     0.004390975        48872.12
	  0.8180879     0.004248867        48906.78
	  0.7899507     0.004238211        48930.59
	  0.7733926      0.00422083        48958.76
	  0.7385842      0.00408545        48985.71
	  0.7231027     0.004059772        49016.21
	  0.7158136     0.004034366        49040.48
	  0.6982324     0.004007952        49068.18
	  0.6723571     0.003961152        49122.27
	  0.6504291     0.003908408         49144.6
	  0.8558546     0.004337911        49212.13
	  0.7691305     0.004050553        49237.74
	  0.7197804     0.003939901        49255.18
	   0.676083     0.003848447        49282.87
	  0.6637431     0.003841962        49308.79
    ------------------------------------------------------------
    PC F439W
	   1.046165     0.006894262        48399.82
		 1.      0.00554368        48428.05
	   1.030861      0.00533668        48453.75
	  0.9871883     0.005156598        48500.62
	   0.965606     0.005047032        48512.36
	  0.9289663     0.004763005        48536.82
	  0.9221467     0.004241654        48564.72
	   0.901156     0.004190775        48593.05
	  0.9003264     0.004154895        48623.35
	  0.8637737     0.003906486         48652.8
		 1.     0.002995234        48657.23
	  0.9682779     0.004221983        48677.66
	  0.9736435     0.004275214        48704.16
	  0.9497296     0.004353564        48732.15
	  0.9028175     0.004237703        48760.18
	  0.8685603     0.003953518        48790.03
	  0.8402335     0.003937545        48817.46
	  0.9826525      0.00426981        48844.16
	  0.9541134     0.004168827        48872.12
	  0.9238468     0.004103727        48906.78
	  0.9061497     0.004009065        48930.59
	  0.9028175     0.004037741        48958.76
	  0.8838937     0.004029295        48985.71
	  0.8814546     0.004041126        49016.21
	  0.8814546     0.004053807        49040.48
	  0.8806432     0.004051672        49068.18
	  0.8519223     0.003984664        49122.27
	  0.8441118     0.003963591         49144.6
	  0.9162205      0.00409513        49212.13
	  0.8945405     0.003881766        49237.74
	   0.851138     0.003787304        49255.18
	  0.8487895     0.003792363        49282.87
	  0.8317637      0.00375602        49308.79
    ------------------------------------------------------------
    PC F555W
	  0.9990794     0.009356521        48399.82
	   1.000921     0.007647147        48428.05
	   1.018591     0.007828623        48453.75
	  0.9772373      0.00706408        48500.62
	   0.991745     0.007327189        48512.36
	  0.9585174     0.006805293        48536.82
	  0.9541134     0.006111814        48564.72
	  0.9298224     0.005884167        48593.05
	   0.934975     0.005975968        48623.35
	  0.8986695     0.005848989         48652.8
		 1.     0.004401105        48657.23
	  0.9772373     0.006063998        48677.66
	  0.9935735     0.006336786        48704.16
	  0.9558726     0.006222661        48732.15
	  0.9366989     0.006053979        48760.18
	  0.9229964     0.005969255        48790.03
	  0.8896107     0.005777722        48817.46
	  0.9647172       0.0060412        48844.16
	  0.9497297     0.005996257        48872.12
	  0.9506048     0.005997869        48906.78
	  0.9506048     0.006060715        48930.59
	  0.9272568     0.006020084        48958.76
	  0.9212977     0.005909632        48985.71
	  0.9221467      0.00593678        49016.21
	  0.9162205     0.005889232        49040.48
	  0.9103324     0.005880265        49068.18
	   0.893717     0.005834306        49122.27
	  0.8920722     0.005824404         49144.6
	  0.9497297     0.005993904        49212.13
	   0.947109     0.005852739        49237.74
	  0.9238469     0.005819524        49255.18
	  0.9120108     0.005758666        49282.87
	  0.9036495      0.00577114        49308.79
    ------------------------------------------------------------
    PC F785LP
	   1.018591      0.01488278        48399.82
	   1.022351      0.01191301        48428.05
	   1.037528      0.01173289        48453.75
	   1.039441      0.01147424        48500.62
	   1.034666      0.01086825        48512.36
	   1.014846      0.01091523        48536.82
	   1.031811     0.009501714        48564.72
	   1.003691     0.009086453        48593.05
	   1.011114     0.009257327        48623.35
	  0.9638291     0.008717684         48652.8
		 1.     0.005615062        48657.23
	  0.9935735     0.009046205        48677.66
	   1.002767     0.009218242        48704.16
	  0.9972408     0.009495005        48732.15
	  0.9972408     0.009365126        48760.18
	  0.9826527     0.008872302        48790.03
	   0.988098     0.008986772        48817.46
	  0.9594007     0.008956269        48844.16
	  0.9754388     0.009019497        48872.12
	   1.006468     0.009167609        48906.78
	  0.9944891     0.008956952        48930.59
	  0.9972408     0.008985654        48958.76
	  0.9763376     0.009063563        48985.71
	  0.9890084     0.009097327        49016.21
	  0.9871884     0.009080522        49040.48
	   0.988098     0.009102392        49068.18
	  0.9772373     0.009103026        49122.27
	  0.9647172     0.009069909         49144.6
	  0.9727473     0.009055705        49212.13
	   1.014846      0.00887019        49237.74
	  0.9963228     0.008714644        49255.18
	  0.9944891     0.008686207        49282.87
	  0.9781377     0.008707569        49308.79
    ------------------------------------------------------------