ETC Request ID: STIS.sp.1184373

Exposure time (seconds) = 0.1000 at wavelength 3936.00 Å

gives: SNR = 68.9399 (per resolution element)

gives: Time to Saturation (for a single exposure) = 0.85 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Result of the calculation 0.05 is less than the minimum exposure time for this detector (0.1)

WARNING MESSAGE: "Electrons per pixel due to background (0.0013) 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 28,159.812 5,631.96 75.05
    Background 0.175 0.04 0.19
        Sky 7.549e-06 1.51e-06 1.23e-03
        Dark Current 0.175 0.04 0.19
    Read Out 32.28
Total in selected region 28,159.987 5,632.00 81.69
Brightest Pixel (single exposure) (at 4010.00 Å) 38,902.138 1,945.11
Global Count Rates
    Source only 54,688,099.913 5,468,809.991
    Background (sky+dark) 26,214.412 2,621.44
Encircled energy fraction 0.94

Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength: 3936
Grating: [G430M] R ~ 6000
Aperture: 0.2X0.09
Gain: 1.0
# Frames: 2
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: Castelli-Kurucz Models K2V 4750 4.5
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 1.33 in filter Johnson/V
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 26.1