ETC Request ID: STIS.im.1163876

Exposure time (seconds) = 1.0000

gives: SNR = 202.5266

gives: Time to Saturation (for a single exposure) = 11.84 seconds

gives: Optimum SNR = 235.4563

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: This observation has a significant filter leak where 42.2 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 0.247 arcsec)
    Source 45,876.392 45,876.39 214.19
    Background 1.934 1.93 1.39
        Sky 0.009 9.28e-03 0.10
        Dark Current 1.925 1.93 1.39
    Read Out 73.71
Total in selected region 45,878.326 45,878.33 226.52
Brightest Pixel (single exposure) 10,130.954 10,130.95
Global Count Rates
    Source only 57,345.490 57,345.490
    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 0.247 arcsec
    Effective Sky Area (pixels) 76.56
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.18
Effective Wavelength 7536.09 Å

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


Target: [point source]
Spectrum: Kurucz Models B3V 18700 3.9
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 0.9 applied before normalization
Normalization: Renormalized to vegamag = 5.7 in filter Johnson/J
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 26.1