ETC Request ID: STIS.sp.1035914

Exposure time (seconds) = 2,100.0000 at wavelength 1425.00 Å

gives: SNR = 67.7948 (per resolution element)

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Buffer time 33.3849 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 1.272 5,342.42 73.09
    Background 0.002 7.35 2.71
        Sky 2.183e-14 9.17e-11 9.57e-06
        Dark Current 0.002 7.35 2.71
Total in selected region 1.274 5,349.77 78.80
Brightest Pixel (single exposure) (at 1297.37 Å) 0.662 1,389.43
Count rate entire detector 59,907.391
Buffer Time (sec) 33.38
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 35,930.792 75,454,663.343
    Background (sky+dark) 262.276 550,779.82
Encircled energy fraction 0.94

Instrument name: STIS
Mode: spectroscopic
Detector: FUVMAMA
Central Wavelength: 1425
Grating: [E140M] R ~ 45800
Aperture: 0.2X0.2
Glow region: medium


Target: [point source]
Spectrum: Standard HST Star Spectra G191B2B (DA0, 11.781) [100.0, 400104.0 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 25.2