ETC Request ID: STIS.im.1035934
Requested Signal/Noise Ratio = 100.000
gives: Time = 0.0270 seconds
gives: Time to Saturation (for a single exposure) = 0.73 seconds
gives: Optimum SNR = 125.0030
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: Result of the calculation 0.013476 is less than the minimum exposure time for this detector (0.1)
WARNING MESSAGE: This observation has a significant filter leak where 9.91 percent of the signal comes from outside the prescribed filter bandpass limits.
WARNING MESSAGE: "Electrons per pixel due to background (0.00024) 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 0.207 arcsec) | |||
| Source | 552,101.997 | 14,880.26 | 121.98 |
| Background | 0.979 | 0.03 | 0.16 |
| Sky | 0.007 | 1.75e-04 | 0.01 |
| Dark Current | 0.972 | 0.03 | 0.16 |
| Read Out | 85.22 | ||
| Total in selected region | 552,102.976 | 14,880.28 | 148.80 |
| Brightest Pixel (single exposure) | 164,027.956 | 2,210.44 | |
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| Global Count Rates | |||
| Source only | 690,127.496 | 18,600.320 | |
| Background (sky+dark) | 18,944.019 | 510.58 | |
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| Background per unit area | |||
| Sky Background (arcsec-2) | 0.049 | 0.001 | |
| Dark Current (arcsec-2) | 7.200 | 0.194 | |
| Extraction region | |||
| circle with radius 0.207 arcsec | |||
| Effective Sky Area (pixels) | 53.61 | ||
| Fraction of flux | 0.80 | ||
| Fraction of flux in brightest pixel | 0.24 | ||
| Effective Wavelength | 5593.57 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 O9 III |
| Extinction E(B-V): | Milky Way Diffuse (Rv=3.1) = 0.1 applied before normalization |
| Normalization: | Renormalized to vegamag = 4.7 in filter Johnson/J |
| Redshift: | None |
| Emission Lines: | None |
| Selected background: | |
| Sky Background: | |
| Level: |
These results were computed using: ETC version 25.2
