ETC Request ID: STIS.im.1163870

Exposure time (seconds) = 1.0000

gives: SNR = 236.3404

gives: Time to Saturation (for a single exposure) = 9.08 seconds

gives: Optimum SNR = 284.4415

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: This observation has a significant filter leak where 49.9 percent of the signal comes from outside the prescribed filter bandpass limits.

WARNING MESSAGE: "Electrons per pixel due to background (0.025) 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."


Plots

Detailed Information Count rate Total counts Associated noise
(e-/s) (e-) (e-)
Counts (circle with radius 0.373 arcsec)
    Source 66,268.466 66,268.47 257.43
    Background 4.396 4.40 2.10
        Sky 0.021 0.02 0.15
        Dark Current 4.375 4.38 2.09
    Read Out 111.12
Total in selected region 66,272.862 66,272.86 280.39
Brightest Pixel (single exposure) 13,216.586 13,216.59
Global Count Rates
    Source only 82,835.583 82,835.583
    Background (sky+dark) 26,283.903 26,283.90
Background per unit area
    Sky Background (arcsec-2) 0.048 0.048
    Dark Current (arcsec-2) 10.000 10.000
Extraction region
circle with radius 0.373 arcsec
    Effective Sky Area (pixels) 174.46
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.16
Effective Wavelength 7998.60 Å

Instrument name: STIS
Mode: imaging
Detector: CCD
Aperture: F28X50OIII
Gain: 4.0
# Frames: 1
Binning: 1
Dark: medium


Target: [point source]
Spectrum: Castelli-Kurucz Models B0I 26000 3.0
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 1.1 applied before normalization
Normalization: Renormalized to vegamag = 5.1 in filter Johnson/J
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 26.1