ETC Request ID: STIS.im.1007423

Exposure time (seconds) = 0.1000

gives: SNR = 1,189.2617

gives: Time to Saturation (for a single exposure) = 0.03 seconds

gives: Optimum SNR = 1,330.6696

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: CCD Full Well limits: total counts per native pixel 393855 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 0.211 arcsec)
    Source 14,181,662.791 1,418,166.28 1,190.87
    Background 5.683 0.57 0.75
        Sky 4.657 0.47 0.68
        Dark Current 1.026 0.10 0.32
    Read Out 61.91
Total in selected region 14,181,668.474 1,418,166.85 1,192.48
Brightest Pixel (single exposure) 3,938,545.377 393,854.54
Global Count Rates
    Source only 17,727,078.488 1,772,707.849
    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 0.211 arcsec
    Effective Sky Area (pixels) 56.04
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.22
Effective Wavelength 6186.98 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 F8V 6200 4.4
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 7.91 in filter Johnson/V
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 25.2