ETC Request ID: STIS.sp.1012957

Requested Signal/Noise Ratio = 40.000 at wavelength 6564.00 Å (per resolution element)

gives: Time = 0.0126 seconds

gives: Time to Saturation (for a single exposure) = 1.42 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Result of the calculation 0.00631088 is less than the minimum exposure time for this detector (0.1)

WARNING MESSAGE: "Electrons per pixel due to background (0.00011) 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."


Table of Source and Noise Counts per Pixel

Plots

Detailed Information Count rate Total counts Associated noise
(e-/s) (e-) (e-)
Counts (box 7 pixels high) (1 pix x 7 pix) (2 pix resel x 7 pix)
    Source 107,398.348 2,711.11 52.07
    Background 0.126 3.18e-03 0.06
        Sky 1.445e-06 3.65e-08 1.91e-04
        Dark Current 0.126 3.18e-03 0.06
    Read Out 43.39
Total in selected region 107,398.474 2,711.12 67.78
Brightest Pixel (single exposure) (at 6295.55 Å) 84,359.968 532.39
Global Count Rates
    Source only 186,331,962.055 2,351,838.830
    Background (sky+dark) 18,874.511 238.23
Encircled energy fraction 0.91

Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength: 6581
Grating: [G750M] R ~ 5000
Aperture: 31X0.05NDC
Gain: 4.0
# Frames: 2
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: Standard HST Star Spectra Sirius (A2V, -1.46) [900.5, 2.997e6 Å]
Extinction E(B-V): None
Normalization: None
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Table of Source and Noise Counts per Pixel

Plots

These results were computed using: ETC version 25.2