ETC Request ID: STIS.sp.640591
Exposure time (seconds) = 0.1000 at wavelength 4451.00 Å
gives: SNR = 7.2024 (per resolution element)
gives: Time to Saturation (for a single exposure) = 51.55 seconds
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: Result of the calculation 0.05 is less than the minimum exposure time for this detector (0.1)
WARNING MESSAGE: "Electrons per pixel due to background (0.00085) 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 | 1,204.680 | 240.94 | 15.52 |
| Background | 0.119 | 0.02 | 0.15 |
| Sky | 8.964e-08 | 1.79e-08 | 1.34e-04 |
| Dark Current | 0.119 | 0.02 | 0.15 |
| Read Out | 29.63 | ||
| Total in selected region | 1,204.799 | 240.96 | 33.45 |
| Brightest Pixel (single exposure) (at 5308.40 Å) | 640.206 | 32.01 | |
|
|
|||
| Global Count Rates | |||
| Source only | 957,695.004 | 95,769.500 | |
| Background (sky+dark) | 17,825.792 | 1,782.58 | |
| Encircled energy fraction | 0.93 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | CCD |
| Central Wavelength: | |
| Grating: | [G430L] R ~ 500 |
| Aperture: | 0.3X0.05ND |
| Gain: | 1.0 |
| # Frames: | 2 |
| Binning: | dispersion: 1, spatial: 1 |
| Dark: |
| Target: [point source] | |
| Spectrum: | Castelli-Kurucz Models K0V 5250 4.5 |
| Extinction E(B-V): | None |
| Normalization: | Renormalized to vegamag = 1.33 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 22.2
