ETC Request ID: STIS.sp.1184851

Exposure time (seconds) = 368.0000 at wavelength 1650.00 Å

gives: SNR = 70.1931 (per resolution element)

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: MAMA Bright limits: total count rate per image 27677 exceeds limit for irregularly-variable sources 40 percent of the bright limit 30000 counts per second

WARNING MESSAGE: Buffer time 72.2623 is less than minimum 99 seconds.


Table of Source and Noise Counts per Pixel

Plots

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 6.705 4,934.79 70.25
    Background 0.011 7.73 2.78
        Sky 9.129e-09 6.72e-06 2.59e-03
        Dark Current 0.011 7.73 2.78
Total in selected region 6.715 4,942.52 70.30
Brightest Pixel (single exposure) (at 2292.80 Å) 13.398 4,930.31
Count rate entire detector 27,676.955
Buffer Time (sec) 72.26
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.
Global Count Rates
    Source only 26,086.901 9,599,979.502
    Background (sky+dark) 1,590.055 585,140.12
Encircled energy fraction 0.82

Instrument name: STIS
Mode: spectroscopic
Detector: NUVMAMA
Central Wavelength:
Grating: [G230L] R ~ 500
Aperture: 52X2


Target: [point source]
Spectrum: Standard HST Star Spectra Grw+70°5824 (DA3, 12.77) [1140.56, 24976.7 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

Plots

These results were computed using: ETC version 26.1