ETC Request ID: STIS.sp.821743
Exposure time (seconds) = 161.0000 at wavelength 6539.00 Å
gives: SNR = 940.8304 (per resolution element)
gives: Time to Saturation (for a single exposure) = 95.85 seconds
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: CCD Full Well limits: total counts per native pixel 201569 exceeds bright limit 120000 for selected gain
WARNING MESSAGE: "Electrons per pixel due to background (3.3) 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."
Table of Source and Noise Counts per Pixel
| Detailed Information | Count rate | Total counts | Associated noise |
| (e-/s) | (e-) | (e-) | |
| Counts (box 7 pixels high) | (1 pix x pix) | (2.0 pix resel x pix) | |
| Source | 2,752.235 | 886,219.78 | 941.39 |
| Background | 0.148 | 47.77 | 6.91 |
| Sky | 0.015 | 4.95 | 2.22 |
| Dark Current | 0.133 | 42.83 | 6.54 |
| Read Out | 31.80 | ||
| Total in selected region | 2,752.384 | 886,267.55 | 941.95 |
| Brightest Pixel (single exposure) (at 6539.40 Å) | 1,251.981 | 201,568.99 | |
|
|
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| Global Count Rates | |||
| Source only | 1,920,023.073 | 309,123,714.792 | |
| Background (sky+dark) | 21,349.248 | 3,437,228.99 | |
| Encircled energy fraction | 0.91 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | CCD |
| Central Wavelength: | |
| Grating: | [G750L] R ~ 500 |
| Aperture: | 52X2 |
| Gain: | 4.0 |
| # Frames: | 1 |
| Binning: | dispersion: 1, spatial: 1 |
| Dark: |
| Target: [point source] | |
| Spectrum: | Pickles Models K5V 4187.94K |
| Extinction E(B-V): | None |
| Normalization: | Renormalized to vegamag = 9.87 in filter Johnson/V |
| Redshift: | None |
| Emission Lines: | None |
| Selected background: | |
| Sky Background: | |
| Level: |
Table of Source and Noise Counts per Pixel
These results were computed using: ETC version 24.2
