ETC Request ID: STIS.sp.636592
Exposure time (seconds) = 633.0000 at wavelength 1978.00 Å
gives: SNR = 65.3847 (per resolution element)
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: MAMA Bright limits: total count rate per image 93960.2 exceeds limit for irregularly-variable sources 40 percent of the bright limit 200000 counts per second
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 | 3.730 | 4,721.80 | 68.72 |
| Background | 0.013 | 15.95 | 3.99 |
| Sky | 4.505e-10 | 5.70e-07 | 7.55e-04 |
| Dark Current | 0.013 | 15.95 | 3.99 |
| Total in selected region | 3.742 | 4,737.76 | 72.22 |
| Brightest Pixel (single exposure) (at 2267.96 Å) | 2.307 | 1,460.30 | |
| Count rate entire detector | 93,960.209 | ||
| Buffer Time (sec) | |||
| 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 | 72,498.248 | 45,891,391.016 | |
| Background (sky+dark) | 1,887.437 | 1,194,747.52 | |
| Encircled energy fraction | 0.93 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | NUVMAMA |
| Central Wavelength: | 1978 |
| Grating: | [E230M] R ~ 30000 |
| Aperture: | 0.2X0.2 |
| Target: [point source] | |
| Spectrum: | Standard HST Star Spectra BD+28°4211 (Op, 10.51) [1140.6, 10242.7 Å] |
| Extinction E(B-V): | None |
| Normalization: | None |
| 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
