ETC Request ID: STIS.sp.1341236

Exposure time (seconds) = 500.0000 at wavelength 1250.00 Å

gives: SNR = 24.7106 (per resolution element)

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Buffer time 52.7333 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 0.752 752.22 27.43
    Background 0.001 1.05 1.02
        Sky 3.969e-14 3.97e-11 6.30e-06
        Dark Current 0.001 1.05 1.02
Total in selected region 0.753 753.27 30.44
Brightest Pixel (single exposure) (at 1303.90 Å) 0.304 151.93
Count rate entire detector 37,926.681
Buffer Time (sec) 52.73
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 20,752.794 10,376,396.907
    Background (sky+dark) 157.445 78,722.28
Encircled energy fraction 0.90

Instrument name: STIS
Mode: spectroscopic
Detector: FUVMAMA
Central Wavelength: 1234
Grating: [E140H] R ~ 114000
Aperture: 0.2X0.2
Glow region: low


Target: [point source]
Spectrum: Flat in units of Fλ
Extinction E(B-V): None
Normalization: Flux 1.5e-11 flam at 5500.0 Å
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 27.1