ETC Request ID: STIS.sp.822465

Exposure time (seconds) = 150.0000 at wavelength 5828.00 Å

gives: SNR = 640.4884 (per resolution element)

gives: Time to Saturation (for a single exposure) = 180.46 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Total counts per binned pixel 99742.6 is within 70 percent of the CCD fullwell limit 120000

WARNING MESSAGE: "Electrons per pixel due to background (3.1) 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 1,370.928 411,278.26 641.31
    Background 0.147 44.02 6.63
        Sky 0.014 4.12 2.03
        Dark Current 0.133 39.90 6.32
    Read Out 31.80
Total in selected region 1,371.074 411,322.28 642.13
Brightest Pixel (single exposure) (at 5828.90 Å) 664.951 99,742.59

Global Count Rates
    Source only 867,613.543 130,142,031.394
    Background (sky+dark) 21,349.248 3,202,387.26

Encircled energy fraction 0.93


Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength:
Grating: [G750L] R ~ 500
Aperture: 52X2
Gain: 4.0
# Frames: 1
Binning: dispersion: 1, spatial: 1
Dark:


Target: [point source]
Spectrum: Kurucz Models F2V 6890 4.3
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 10.04 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 24.2