ETC Request ID: STIS.im.720208
Exposure time (seconds) = 1.5000
gives: SNR = 620.3221
gives: Time to Saturation (for a single exposure) = 1.94 seconds
gives: Optimum SNR = 699.1545
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: "Electrons per pixel due to background (0.034) 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 0.231 arcsec) | |||
| Source | 262,836.984 | 394,255.48 | 627.90 |
| Background | 4.524 | 6.79 | 2.60 |
| Sky | 3.251 | 4.88 | 2.21 |
| Dark Current | 1.273 | 1.91 | 1.38 |
| Read Out | 98.39 | ||
| Total in selected region | 262,841.507 | 394,262.26 | 635.57 |
| Brightest Pixel (single exposure) | 61,722.752 | 46,292.06 | |
|
|
|||
| Global Count Rates | |||
| Source only | 328,546.230 | 492,819.344 | |
| Background (sky+dark) | 47,816.621 | 71,724.93 | |
|
|
|||
| Background per unit area | |||
| Sky Background (arcsec-2) | 19.457 | 29.186 | |
| Dark Current (arcsec-2) | 7.600 | 11.400 | |
| Extraction region | |||
| circle with radius 0.231 arcsec | |||
| Effective Sky Area (pixels) | 66.83 | ||
| Fraction of flux | 0.80 | ||
| Fraction of flux in brightest pixel | 0.19 | ||
| Effective Wavelength | 7225.94 Å | ||
| Instrument name: | STIS |
| Mode: | imaging |
| Detector: | CCD |
| Aperture: | F28X50LP |
| Gain: | 4.0 |
| # Frames: | 2 |
| Binning: | 1 |
| Dark: |
| Target: [point source] | |
| Spectrum: | Kurucz Models K0V 5250 4.5 |
| Extinction E(B-V): | None |
| Normalization: | Renormalized to vegamag = 11.76 in filter Johnson/V |
| Redshift: | None |
| Emission Lines: | None |
| Selected background: | |
| Sky Background: | |
| Level: |
These results were computed using: ETC version 23.2
