ETC Request ID: STIS.im.825320

Exposure time (seconds) = 0.2000

gives: SNR = 397.7404

gives: Time to Saturation (for a single exposure) = 0.61 seconds

gives: Optimum SNR = 448.9151

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: "Electrons per pixel due to background (0.0091) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). We suggest you consider CTE mitigation strategies described in the STIS Instrument Handbook."



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Detailed Information Count rate Total counts Associated noise
(e-/s) (e-) (e-)
Counts (circle with radius 0.228 arcsec)
    Source 814,155.339 162,831.07 403.52
    Background 4.419 0.88 0.94
        Sky 3.165 0.63 0.80
        Dark Current 1.254 0.25 0.50
    Read Out 69.05
Total in selected region 814,159.758 162,831.95 409.39
Brightest Pixel (single exposure) 195,620.922 39,124.18

Global Count Rates
    Source only 1,017,694.174 203,538.835
    Background (sky+dark) 47,758.524 9,551.70

Background per unit area
    Sky Background (arcsec-2) 19.417 3.883
    Dark Current (arcsec-2) 7.600 1.520

Extraction region
circle with radius 0.228 arcsec
    Effective Sky Area (pixels) 65.20
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.19
Effective Wavelength 7105.01 Å


Instrument name: STIS
Mode: imaging
Detector: CCD
Aperture: F28X50LP
Gain: 4.0
# Frames: 1
Binning: 1
Dark:


Target: [point source]
Spectrum: Kurucz Models F5V 6440 4.3
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 10.3 in filter Johnson/V
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:


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These results were computed using: ETC version 24.2