ETC Request ID: STIS.im.1013969

Exposure time (seconds) = 0.1000

gives: SNR = 1,796.6346

gives: Time to Saturation (for a single exposure) = 0.01 seconds

gives: Optimum SNR = 2,009.3569

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: CCD Full Well limits: total counts per native pixel 916689 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 0.21 arcsec)
    Source 32,316,573.933 3,231,657.39 1,797.68
    Background 5.603 0.56 0.75
        Sky 4.595 0.46 0.68
        Dark Current 1.008 0.10 0.32
    Read Out 61.36
Total in selected region 32,316,579.536 3,231,657.95 1,798.73
Brightest Pixel (single exposure) 9,166,885.724 916,688.57
Global Count Rates
    Source only 40,395,717.417 4,039,571.742
    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 0.21 arcsec
    Effective Sky Area (pixels) 55.29
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.23
Effective Wavelength 6005.12 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 F2V 6890 4.3
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 7.0 in filter Johnson/V
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 25.2