ETC Request ID: STIS.ta.510225

Requested Signal/Noise Ratio = 40.000

gives: Time = 0.0001 seconds

gives: Time to Saturation (for a single exposure) = 0.54 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Result of the calculation 6.27847e-05 is less than the minimum exposure time for this detector (0.1)

WARNING MESSAGE: "Electrons per pixel due to background (2.75077e-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 (box of 37 x 37 pixels)
    Source 201,752,898.800 12,667.00 112.55
    Background 90.394 5.68e-03 0.08
        Sky 67.121 4.21e-03 0.06
        Dark Current 23.273 1.46e-03 0.04
    Read Out 296.00
Total in selected region 201,752,989.194 12,667.00 316.67
Brightest Pixel (single exposure) 222,214.399 13.95
Global Count Rates
    Source only 201,752,898.800 12,666.997
    Background (sky+dark) 45,941.022 2.88
Background per unit area
    Sky Background (arcsec-2) 19.612 0.001
    Dark Current (arcsec-2) 6.800 4.269e-04
Extraction region
box of 37 x 37 pixels
    Effective Sky Area (pixels) 1,369.00
Effective Wavelength 7168.00 Å

Instrument name: STIS
Mode: Target Acquisition
Detector: CCD
Acquisition Mode: ACQ
Aperture: F28X50LP
Gain: 4.0
# Frames: 1
Binning:
Dark:


Target: [extended source]
Source diameter (arcsec): 1.7
Spectrum: Castelli-Kurucz Models G2V 5750 4.5
Extinction E(B-V): None
Normalization: Renormalized to Johnson V = 5.57 in magnitudes relative to Vega
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 21.2