ETC Request ID: STIS.ta.1009209

Requested Signal/Noise Ratio = 40.000

gives: Time = 0.0941 seconds

gives: Time to Saturation (for a single exposure) = 13.93 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Result of the calculation 0.0940897 is less than the minimum exposure time for this detector (0.1)


Plots

Detailed Information Count rate Total counts Associated noise
(e-/s) (e-) (e-)
Counts (box of 3 x 3 pixels)
    Source 21,981.225 2,068.21 45.48
    Background 0.597 0.06 0.24
        Sky 0.435 0.04 0.20
        Dark Current 0.162 0.02 0.12
    Read Out 24.60
Total in selected region 21,981.822 2,068.26 51.71
Brightest Pixel (single exposure) 8,614.096 810.50
Global Count Rates
    Source only 43,962.450 4,136.412
    Background (sky+dark) 46,585.728 4,383.23
Background per unit area
    Sky Background (arcsec-2) 19.330 1.819
    Dark Current (arcsec-2) 7.200 0.677
Extraction region
box of 3 x 3 pixels
    Effective Sky Area (pixels) 9.00
    Fraction of flux 0.50
    Fraction of flux in brightest pixel 0.20
Effective Wavelength 7001.65 Å

Instrument name: STIS
Mode: Target Acquisition
Detector: CCD
Acquisition Mode: ACQ
Aperture: F28X50LP
Gain: 4.0
# Frames: 1
Binning: 1
Dark: medium


Target: [point source]
Spectrum: Kurucz Models A3V 8720 4.2
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 0.1 applied before normalization
Normalization: Renormalized to vegamag = 13.46 in filter Johnson/V
Redshift: None
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Plots

These results were computed using: ETC version 25.2