ETC Request ID: STIS.sp.1009272
Requested Signal/Noise Ratio = 20.000 at wavelength 4451.00 Å (per resolution element)
gives: Time = 90.1860 seconds
gives: Time to Saturation (for a single exposure) = 2,373.64 seconds
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: "Electrons per pixel due to background (0.82) 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 7 pix) | (2 pix resel x 7 pix) | |
| Source | 4.949 | 892.59 | 29.88 |
| Background | 0.127 | 22.87 | 4.78 |
| Sky | 7.822e-04 | 0.14 | 0.38 |
| Dark Current | 0.126 | 22.73 | 4.77 |
| Read Out | 32.81 | ||
| Total in selected region | 5.075 | 915.45 | 44.63 |
| Brightest Pixel (single exposure) (at 4552.40 Å) | 13.903 | 626.91 | |
|
|
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| Global Count Rates | |||
| Source only | 6,054.041 | 545,989.661 | |
| Background (sky+dark) | 18,955.825 | 1,709,549.78 | |
| Encircled energy fraction | 0.93 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | CCD |
| Central Wavelength: | |
| Grating: | [G430L] R ~ 500 |
| Aperture: | 52X0.2 |
| Gain: | 1.0 |
| # Frames: | 2 |
| Binning: | dispersion: 1, spatial: 1 |
| Dark: | medium |
| Target: [point source] | |
| Spectrum: | User uploaded spectrum: trappist1.dat |
| Extinction E(B-V): | None |
| Normalization: | None |
| 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 25.2
