ETC Request ID: STIS.sp.1048611

Requested Signal/Noise Ratio = 40.000 at wavelength 2026.00 Å (per resolution element)

gives: Time = 8.7521 seconds

gives: Time to Saturation (for a single exposure) = 88.74 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: "Electrons per pixel due to background (0.16) 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 129.465 2,266.19 47.60
    Background 0.126 2.21 1.49
        Sky 1.093e-08 1.91e-07 4.37e-04
        Dark Current 0.126 2.21 1.49
    Read Out 30.68
Total in selected region 129.591 2,268.39 56.65
Brightest Pixel (single exposure) (at 3065.10 Å) 1,352.207 11,834.66
Global Count Rates
    Source only 1,174,071.895 10,275,602.468
    Background (sky+dark) 18,874.374 165,190.53
Encircled energy fraction 0.93

Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength:
Grating: [G230LB] R ~ 700
Aperture: 0.2X0.06
Gain: 4.0
# Frames: 1
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: Kurucz Models O9V 33000. 4.0
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 0.59 applied before normalization
Normalization: Renormalized to vegamag = 6.7 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 25.2