ETC Request ID: STIS.sp.1012191
Requested Signal/Noise Ratio = 40.000 at wavelength 2026.00 Å (per resolution element)
gives: Time = 14.5785 seconds
gives: Time to Saturation (for a single exposure) = 148.26 seconds
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: "Electrons per pixel due to background (0.26) 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 | 77.751 | 2,266.99 | 47.61 |
| Background | 0.126 | 3.67 | 1.92 |
| Sky | 1.045e-09 | 3.05e-08 | 1.75e-04 |
| Dark Current | 0.126 | 3.67 | 1.92 |
| Read Out | 30.68 | ||
| Total in selected region | 77.877 | 2,270.66 | 56.67 |
| Brightest Pixel (single exposure) (at 3065.10 Å) | 809.371 | 11,799.40 | |
|
|
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| Global Count Rates | |||
| Source only | 701,100.587 | 10,220,977.973 | |
| Background (sky+dark) | 18,874.420 | 275,160.28 | |
| Encircled energy fraction | 0.93 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | CCD |
| Central Wavelength: | |
| Grating: | [G230LB] R ~ 700 |
| Aperture: | 31X0.05NDB |
| Gain: | 4.0 |
| # Frames: | 1 |
| Binning: | dispersion: 1, spatial: 1 |
| Dark: | medium |
| Target: [point source] | |
| Spectrum: | Castelli-Kurucz Models B3V 19000 4.0 |
| Extinction E(B-V): | Milky Way Diffuse (Rv=3.1) = 0.52 applied before normalization |
| Normalization: | Renormalized to vegamag = 4.42 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 25.2
