ETC Request ID: STIS.sp.919784
Requested Signal/Noise Ratio = 95.000 at wavelength 2260.00 Å (per resolution element)
gives: Time = 2,028.0336 seconds
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: MAMA Bright limits: total count rate per image 110029 exceeds limit for irregularly-variable sources 40 percent of the bright limit 200000 counts per second
WARNING MESSAGE: Buffer time 18.177 is less than minimum 99 seconds.
Table of Source and Noise Counts per Pixel
| Detailed Information | Count rate | Total counts | Associated noise |
| (counts/s) | (counts) | (counts) | |
| Counts (box 7 pixels high) | (1 pix x pix) | (2.0 pix resel x pix) | |
| Source | 2.383 | 9,666.43 | 98.32 |
| Background | 0.011 | 42.59 | 6.53 |
| Sky | 4.578e-10 | 1.86e-06 | 1.36e-03 |
| Dark Current | 0.011 | 42.59 | 6.53 |
| Total in selected region | 2.394 | 9,709.02 | 101.75 |
| Brightest Pixel (single exposure) (at 2304.78 Å) | 1.443 | 2,925.74 | |
| Count rate entire detector | 110,029.441 | ||
| Buffer Time (sec) | 18.18 | ||
| For APT purposes, the recommended buffer time should be 4/5 of the buffer time calculated above. Please refer to the STIS Instrument Handbook for more details. | |||
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| Global Count Rates | |||
| Source only | 79,864.728 | 161,968,348.235 | |
| Background (sky+dark) | 1,572.864 | 3,189,821.02 | |
| Encircled energy fraction | 0.93 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | NUVMAMA |
| Central Wavelength: | 2263 |
| Grating: | [E230H] R ~ 114000 |
| Aperture: | 0.2X0.09 |
| Target: [point source] | |
| Spectrum: | Castelli-Kurucz Models F2V 7000 4.0 |
| Extinction E(B-V): | None |
| Normalization: | Flux 1.9e-11 flam at 2260.0 Å |
| 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 25.1.1
