ETC Request ID: STIS.im.825271

Exposure time (seconds) = 0.1000

gives: SNR = 514.5417

gives: Time to Saturation (for a single exposure) = 0.19 seconds

gives: Optimum SNR = 578.8401

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: "Electrons per pixel due to background (0.0046) 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 0.233 arcsec)
    Source 2,696,484.029 269,648.40 519.28
    Background 4.626 0.46 0.68
        Sky 3.315 0.33 0.58
        Dark Current 1.311 0.13 0.36
    Read Out 70.61
Total in selected region 2,696,488.654 269,648.87 524.06
Brightest Pixel (single exposure) 620,295.178 62,029.52

Global Count Rates
    Source only 3,370,605.036 337,060.504
    Background (sky+dark) 47,758.524 4,775.85

Background per unit area
    Sky Background (arcsec-2) 19.417 1.942
    Dark Current (arcsec-2) 7.600 0.760

Extraction region
circle with radius 0.233 arcsec
    Effective Sky Area (pixels) 68.28
    Fraction of flux 0.80
    Fraction of flux in brightest pixel 0.18
Effective Wavelength 7332.48 Å


Instrument name: STIS
Mode: imaging
Detector: CCD
Aperture: F28X50LP
Gain: 4.0
# Frames: 1
Binning: 1
Dark:


Target: [point source]
Spectrum: Kurucz Models K4V 4560 4.5
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 9.47 in filter Johnson/V
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:


Plots

These results were computed using: ETC version 24.2