ETC Request ID: STIS.sp.1012025
Requested Signal/Noise Ratio = 50.000 at wavelength 2026.00 Å (per resolution element)
gives: Time = 1,507.1219 seconds
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: Buffer time 63.895 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 7 pix) | (2 pix resel x 7 pix) | |
| Source | 0.914 | 2,756.21 | 52.50 |
| Background | 0.011 | 31.65 | 5.63 |
| Sky | 6.146e-13 | 1.85e-09 | 4.30e-05 |
| Dark Current | 0.011 | 31.65 | 5.63 |
| Total in selected region | 0.925 | 2,787.86 | 55.12 |
| Brightest Pixel (single exposure) (at 2319.51 Å) | 0.889 | 1,339.56 | |
| Count rate entire detector | 31,301.335 | ||
| Buffer Time (sec) | 63.90 | ||
| 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 | 23,408.259 | 35,279,099.833 | |
| Background (sky+dark) | 1,572.864 | 2,370,497.81 | |
| Encircled energy fraction | 0.93 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | NUVMAMA |
| Central Wavelength: | 1978 |
| Grating: | [E230M] R ~ 30000 |
| Aperture: | 0.2X0.05ND |
| Target: [point source] | |
| Spectrum: | Castelli-Kurucz Models B0III 29000 3.5 |
| Extinction E(B-V): | Milky Way Diffuse (Rv=3.1) = 0.31 applied before normalization |
| Normalization: | Renormalized to vegamag = 3.83 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
