ETC Request ID: STIS.sp.995058

Exposure time (seconds) = 120.0000 at wavelength 7569.00 Å

gives: SNR = 37.7556 (per resolution element)

gives: Time to Saturation (for a single exposure) = 3,124.45 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: "Electrons per pixel due to background (1.1) 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 pix) (2.0 pix resel x pix)
    Source 8.987 2,156.97 46.44
    Background 0.127 30.53 5.53
        Sky 0.001 0.29 0.54
        Dark Current 0.126 30.24 5.50
    Read Out 32.81
Total in selected region 9.115 2,187.50 57.13
Brightest Pixel (single exposure) (at 6997.55 Å) 10.562 633.71

Global Count Rates
    Source only 22,890.072 2,746,808.668
    Background (sky+dark) 19,265.745 2,311,889.36

Encircled energy fraction 0.87


Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength: 7283
Grating: [G750M] R ~ 5000
Aperture: 52X2
Gain: 1.0
# Frames: 2
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: Standard HST Star Spectra AGK+81°266 (sdO, 11.94) [1148.6, 24955.1 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 25.1.1