ETC Request ID: STIS.im.1184782
Exposure time (seconds) = 110.0000
gives: SNR = 341.1528
gives: Time to Saturation (for a single exposure) = 303.58 seconds
gives: Optimum SNR = 388.7092
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: "Electrons per pixel due to background (1.4) 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."
| Detailed Information | Count rate | Total counts | Associated noise |
| (e-/s) | (e-) | (e-) | |
| Counts (circle with radius 0.194 arcsec) | |||
| Source | 1,117.493 | 122,924.21 | 350.61 |
| Background | 1.206 | 132.61 | 11.52 |
| Sky | 0.006 | 0.61 | 0.78 |
| Dark Current | 1.200 | 132.00 | 11.49 |
| Read Out | 82.30 | ||
| Total in selected region | 1,118.698 | 123,056.82 | 360.32 |
| Brightest Pixel (single exposure) | 395.285 | 21,740.68 | |
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| Global Count Rates | |||
| Source only | 1,396.866 | 153,655.262 | |
| Background (sky+dark) | 26,281.044 | 2,890,914.87 | |
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| Background per unit area | |||
| Sky Background (arcsec-2) | 0.046 | 5.114 | |
| Dark Current (arcsec-2) | 10.000 | 1,100.000 | |
| Extraction region | |||
| circle with radius 0.194 arcsec | |||
| Effective Sky Area (pixels) | 47.35 | ||
| Fraction of flux | 0.80 | ||
| Fraction of flux in brightest pixel | 0.28 | ||
| Effective Wavelength | 3737.95 Å | ||
| Instrument name: | STIS |
| Mode: | imaging |
| Detector: | CCD |
| Aperture: | F28X50OII |
| Gain: | 4.0 |
| # Frames: | 2 |
| Binning: | 1 |
| Dark: | medium |
| Target: [point source] | |
| Spectrum: | Standard HST Star Spectra Grw+70°5824 (DA3, 12.77) [1140.56, 24976.7 Å] |
| Extinction E(B-V): | None |
| Normalization: | None |
| Redshift: | None |
| Emission Lines: | None |
| Selected background: | |
| Sky Background: | |
| Level: |
These results were computed using: ETC version 26.1
