ETC Request ID: STIS.sp.1046485

Requested Signal/Noise Ratio = 10.000 at wavelength 2796.00 Å (per resolution element)

gives: Time = 9.8074 seconds

gives: Time to Saturation (for a single exposure) = 3,010.97 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: "Electrons per pixel due to background (0.088) 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 19.487 382.23 19.55
    Background 0.126 2.47 1.57
        Sky 2.247e-06 4.41e-05 6.64e-03
        Dark Current 0.126 2.47 1.57
    Read Out 32.81
Total in selected region 19.613 384.71 38.22
Brightest Pixel (single exposure) (at 2796.00 Å) 10.960 53.74
Global Count Rates
    Source only 275.434 2,701.298
    Background (sky+dark) 18,879.489 185,159.29
Encircled energy fraction 0.94

Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength:
Grating: [G230LB] R ~ 700
Aperture: 52X0.2
Gain: 1.0
# Frames: 2
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: Black body at 3300.0K
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 13.528 in filter Johnson/U
Redshift: None
Emission Lines:
Line at Center 2796.0 Å    FWHM 1.6 Å   Flux 3.9e-13 Fλ
Line at Center 2804.0 Å    FWHM 1.6 Å   Flux 2.9e-13 Fλ


Selected background:
  Sky Background:
    Level:

Table of Source and Noise Counts per Pixel

Plots

These results were computed using: ETC version 25.2