ETC Request ID: STIS.im.1007417

Exposure time (seconds) = 0.1000

gives: SNR = 341.6448

gives: Time to Saturation (for a single exposure) = 0.44 seconds

gives: Optimum SNR = 386.9255

Exposure time calculation HAD WARNINGS.

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."



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Detailed Information Count rate Total counts Associated noise
(e-/s) (e-) (e-)
Counts (circle with radius 0.235 arcsec)
    Source 1,212,527.276 121,252.73 348.21
    Background 7.047 0.70 0.84
        Sky 5.787 0.58 0.76
        Dark Current 1.260 0.13 0.35
    Read Out 68.61
Total in selected region 1,212,534.322 121,253.43 354.91
Brightest Pixel (single exposure) 273,604.279 27,360.43

Global Count Rates
    Source only 1,515,659.095 151,565.909
    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 0.235 arcsec
    Effective Sky Area (pixels) 69.63
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.18
Effective Wavelength 7430.05 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 M2V 3500 4.6
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 11.16 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 25.2