ETC Request ID: STIS.sp.1166542

Exposure time (seconds) = 320.0000 at wavelength 9428.00 Å

gives: SNR = 1,508.4857 (per resolution element)

gives: Time to Saturation (for a single exposure) = 15.02 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: CCD Full Well limits: total counts per native pixel 703060 exceeds bright limit 33000 for selected gain

WARNING MESSAGE: "Electrons per pixel due to background (8) 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 3,556.503 2,276,161.93 1,508.70
    Background 0.175 112.03 10.58
        Sky 4.950e-05 0.03 0.18
        Dark Current 0.175 112.00 10.58
    Read Out 22.82
Total in selected region 3,556.678 2,276,273.96 1,508.91
Brightest Pixel (single exposure) (at 9050.55 Å) 2,197.062 703,059.74
Global Count Rates
    Source only 5,680,628.518 1,817,801,125.877
    Background (sky+dark) 26,222.337 8,391,147.91
Encircled energy fraction 0.69

Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength: 9336
Grating: [G750M] R ~ 5000
Aperture: 52X0.1
Gain: 1.0
# Frames: 1
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: Kurucz Models B5V 15400 3.9
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 0.02 applied before normalization
Normalization: Renormalized to vegamag = 4.5 in filter Johnson/J
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