ETC Request ID: STIS.sp.822001

Exposure time (seconds) = 253.0000 at wavelength 6519.00 Å

gives: SNR = 389.5107 (per resolution element)

gives: Time to Saturation (for a single exposure) = 872.48 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: "Electrons per pixel due to background (5.2) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). We suggest you consider CTE mitigation strategies described in the STIS Instrument Handbook."


Table of Source and Noise Counts per Pixel


Plots


Detailed Information Count rate Total counts Associated noise
(e-/s) (e-) (e-)
Counts (box 7 pixels high) (1 pix x pix) (2.0 pix resel x pix)
    Source 301.971 152,797.53 390.89
    Background 0.148 75.09 8.67
        Sky 0.015 7.80 2.79
        Dark Current 0.133 67.30 8.20
    Read Out 31.80
Total in selected region 302.120 152,872.62 392.28
Brightest Pixel (single exposure) (at 6519.80 Å) 137.540 34,797.50

Global Count Rates
    Source only 205,385.559 51,962,546.346
    Background (sky+dark) 21,349.248 5,401,359.85

Encircled energy fraction 0.91


Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength:
Grating: [G750L] R ~ 500
Aperture: 52X2
Gain: 4.0
# Frames: 1
Binning: dispersion: 1, spatial: 1
Dark:


Target: [point source]
Spectrum: Pickles Models K2V 4886.52K
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 12.0 in filter Johnson/V
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 24.2