ETC Request ID: STIS.sp.1014735

Exposure time (seconds) = 700.0000 at wavelength 2000.00 Å

gives: SNR = 22.9175 (per resolution element)

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: MAMA Bright limits: total count rate per image 15372.6 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 2 pixels high) (1 pix x 2 pix) (2 pix resel x 2 pix)
    Source 0.378 529.38 23.01
    Background 0.003 4.20 2.05
        Sky 8.101e-09 1.13e-05 3.37e-03
        Dark Current 0.003 4.20 2.05
Total in selected region 0.381 533.58 23.10
Brightest Pixel (single exposure) (at 2907.20 Å) 29.696 20,787.14
Count rate entire detector 15,372.585

Buffer Time (sec) 130.10
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 13,798.849 9,659,194.631
    Background (sky+dark) 1,573.735 1,101,614.65



Instrument name: STIS
Mode: spectroscopic
Detector: NUVMAMA
Central Wavelength:
Grating: [G230L] R ~ 500
Aperture: 52X0.1


Target: [extended source]
Source diameter (arcsec): 0.064
Spectrum: Standard HST Star Spectra Solar Spectrum (G2V, -26.75) [1195.0, 26957.4 Å]
Extinction E(B-V): None
Normalization: Flux 1.77e-12 flam at 2000.0 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 25.2