ETC Request ID: STIS.im.1163872

Exposure time (seconds) = 0.5000

gives: SNR = 317.2038

gives: Time to Saturation (for a single exposure) = 2.23 seconds

gives: Optimum SNR = 359.0725

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: This observation has a significant filter leak where 29.1 percent of the signal comes from outside the prescribed filter bandpass limits.

WARNING MESSAGE: "Electrons per pixel due to background (0.013) 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 0.219 arcsec)
    Source 209,506.476 104,753.24 323.66
    Background 1.532 0.77 0.88
        Sky 0.007 3.67e-03 0.06
        Dark Current 1.525 0.76 0.87
    Read Out 65.61
Total in selected region 209,508.009 104,754.00 330.24
Brightest Pixel (single exposure) 53,715.274 26,857.64
Global Count Rates
    Source only 261,883.095 130,941.548
    Background (sky+dark) 26,283.903 13,141.95
Background per unit area
    Sky Background (arcsec-2) 0.048 0.024
    Dark Current (arcsec-2) 10.000 5.000
Extraction region
circle with radius 0.219 arcsec
    Effective Sky Area (pixels) 60.49
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.21
Effective Wavelength 6746.90 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 B1V 25400 3.9
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 0.7 applied before normalization
Normalization: Renormalized to vegamag = 4.5 in filter Johnson/J
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 26.1