ETC Request ID: STIS.im.1013982

Exposure time (seconds) = 0.1000

gives: SNR = 1,340.8365

gives: Time to Saturation (for a single exposure) = 0.02 seconds

gives: Optimum SNR = 1,500.0043

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: CCD Full Well limits: total counts per native pixel 532348 exceeds bright limit 120000 for selected gain

WARNING MESSAGE: "Electrons per pixel due to background (0.01) 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."


Plots

Detailed Information Count rate Total counts Associated noise
(e-/s) (e-) (e-)
Counts (circle with radius 0.207 arcsec)
    Source 18,014,668.382 1,801,466.84 1,342.19
    Background 5.444 0.54 0.74
        Sky 4.472 0.45 0.67
        Dark Current 0.972 0.10 0.31
    Read Out 60.26
Total in selected region 18,014,673.826 1,801,467.38 1,343.54
Brightest Pixel (single exposure) 5,323,477.963 532,347.80
Global Count Rates
    Source only 22,518,335.478 2,251,833.548
    Background (sky+dark) 106,019.251 10,601.93
Background per unit area
    Sky Background (arcsec-2) 33.243 3.324
    Dark Current (arcsec-2) 7.200 0.720
Extraction region
circle with radius 0.207 arcsec
    Effective Sky Area (pixels) 53.81
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.24
Effective Wavelength 5642.24 Å

Instrument name: STIS
Mode: imaging
Detector: CCD
Aperture: 50CCD
Gain: 4.0
# Frames: 1
Binning: 1
Dark: medium


Target: [point source]
Spectrum: Kurucz Models A3V 8720 4.2
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 7.605 in filter Johnson/V
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 25.2