ETC Request ID: STIS.im.825282
Exposure time (seconds) = 0.9000
gives: SNR = 451.2846
gives: Time to Saturation (for a single exposure) = 2.23 seconds
gives: Optimum SNR = 508.5025
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: "Electrons per pixel due to background (0.041) 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 0.232 arcsec) | |||
| Source | 231,623.952 | 208,461.56 | 456.58 |
| Background | 4.566 | 4.11 | 2.03 |
| Sky | 3.274 | 2.95 | 1.72 |
| Dark Current | 1.292 | 1.16 | 1.08 |
| Read Out | 70.09 | ||
| Total in selected region | 231,628.518 | 208,465.67 | 461.93 |
| Brightest Pixel (single exposure) | 53,919.503 | 48,527.55 | |
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| Global Count Rates | |||
| Source only | 289,529.940 | 260,576.946 | |
| Background (sky+dark) | 47,758.524 | 42,982.67 | |
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| Background per unit area | |||
| Sky Background (arcsec-2) | 19.417 | 17.475 | |
| Dark Current (arcsec-2) | 7.600 | 6.840 | |
| Extraction region | |||
| circle with radius 0.232 arcsec | |||
| Effective Sky Area (pixels) | 67.45 | ||
| Fraction of flux | 0.80 | ||
| Fraction of flux in brightest pixel | 0.19 | ||
| Effective Wavelength | 7271.36 Å | ||
| Instrument name: | STIS |
| Mode: | imaging |
| Detector: | CCD |
| Aperture: | F28X50LP |
| Gain: | 4.0 |
| # Frames: | 1 |
| Binning: | 1 |
| Dark: |
| Target: [point source] | |
| Spectrum: | Pickles Models K2V 4886.52K |
| Extinction E(B-V): | None |
| Normalization: | Renormalized to vegamag = 12.0 in filter Johnson/V |
| Redshift: | None |
| Emission Lines: | None |
| Selected background: | |
| Sky Background: | |
| Level: |
These results were computed using: ETC version 24.2
