ETC Request ID: STIS.sp.636596

Exposure time (seconds) = 368.0000 at wavelength 1425.00 Å

gives: SNR = 132.8562 (per resolution element)

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: MAMA Bright limits: total count rate per image 20114.2 exceeds limit for irregularly-variable sources 40 percent of the bright limit 30000 counts per second


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 pix) (2.0 pix resel x pix)
    Source 23.983 17,651.55 132.86
    Background 0.001 0.77 0.88
        Sky 2.928e-12 2.16e-09 4.64e-05
        Dark Current 0.001 0.77 0.88
Total in selected region 23.984 17,652.32 132.86
Brightest Pixel (single exposure) (at 1286.10 Å) 13.031 4,795.37
Count rate entire detector 20,114.227
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.
Global Count Rates
    Source only 19,840.901 7,301,451.513
    Background (sky+dark) 273.326 100,583.95
Encircled energy fraction 0.83

Instrument name: STIS
Mode: spectroscopic
Detector: FUVMAMA
Central Wavelength:
Grating: [G140L] R ~ 1000
Aperture: 52X0.2
Glow region:


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 22.2