ETC Request ID: STIS.im.1013945

Requested Signal/Noise Ratio = 10.000

gives: Time = 0.0000 seconds

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

gives: Optimum SNR = 15.7103

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Result of the calculation 4.06252e-05 is less than the minimum exposure time for this detector (0.1)

WARNING MESSAGE: "Electrons per pixel due to background (4.1e-06) 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 0.212 arcsec)
    Source 16,519,346.211 671.10 25.91
    Background 5.719 2.32e-04 0.02
        Sky 4.693 1.91e-04 0.01
        Dark Current 1.026 4.17e-05 6.46e-03
    Read Out 61.91
Total in selected region 16,519,351.930 671.10 67.11
Brightest Pixel (single exposure) 4,532,700.517 184.14
Global Count Rates
    Source only 20,649,182.764 838.878
    Background (sky+dark) 106,019.251 4.31
Background per unit area
    Sky Background (arcsec-2) 33.243 0.001
    Dark Current (arcsec-2) 7.200 2.925e-04
Extraction region
circle with radius 0.212 arcsec
    Effective Sky Area (pixels) 56.46
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.22
Effective Wavelength 6289.07 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 G2V 5860 4.4
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 7.755 in filter Johnson/V
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 25.2