ETC Request ID: STIS.im.1035926

Requested Signal/Noise Ratio = 100.000

gives: Time = 0.2575 seconds

gives: Time to Saturation (for a single exposure) = 6.69 seconds

gives: Optimum SNR = 169.3260

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: This observation has a significant filter leak where 56.8 percent of the signal comes from outside the prescribed filter bandpass limits.

WARNING MESSAGE: "Electrons per pixel due to background (0.0023) 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 0.486 arcsec)
    Source 99,543.698 25,634.06 160.11
    Background 5.400 1.39 1.18
        Sky 0.036 9.29e-03 0.10
        Dark Current 5.364 1.38 1.18
    Read Out 200.19
Total in selected region 99,549.098 25,635.45 256.34
Brightest Pixel (single exposure) 17,930.077 2,308.64
Global Count Rates
    Source only 124,429.622 32,042.571
    Background (sky+dark) 18,944.019 4,878.38
Background per unit area
    Sky Background (arcsec-2) 0.049 0.013
    Dark Current (arcsec-2) 7.200 1.854
Extraction region
circle with radius 0.486 arcsec
    Effective Sky Area (pixels) 297.01
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.14
Effective Wavelength 8416.27 Å

Instrument name: STIS
Mode: imaging
Detector: CCD
Aperture: F28X50OIII
Gain: 4.0
# Frames: 2
Binning: 1
Dark: medium


Target: [point source]
Spectrum: Bruzual Synthetic Stellar Spectra B0.5 I
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 1.1 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 25.2