ETC Request ID: STIS.sp.636585

Exposure time (seconds) = 350.0000 at wavelength 1425.00 Å

gives: SNR = 34.0923 (per resolution element)

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: MAMA Bright limits: total count rate per image 84296.2 exceeds limit for irregularly-variable sources 40 percent of the bright limit 200000 counts per second


Table of Source and Noise Counts per Pixel

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 1.929 1,350.04 36.74
    Background 0.001 0.74 0.86
        Sky 2.199e-14 1.54e-11 3.92e-06
        Dark Current 0.001 0.73 0.86
Total in selected region 1.930 1,350.77 39.60
Brightest Pixel (single exposure) (at 1320.94 Å) 0.908 317.87
Count rate entire detector 84,296.201
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 50,685.985 17,740,094.735
    Background (sky+dark) 157.423 55,097.90
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:


Target: [point source]
Spectrum: Standard HST Star Spectra BD+28°4211 (Op, 10.51) [1140.6, 10242.7 Å]
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 0.11 applied before normalization
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