ETC Request ID: STIS.sp.1038588

Requested Signal/Noise Ratio = 50.000 at wavelength 2026.00 Å (per resolution element)

gives: Time = 526.3500 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Buffer time 25.3019 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 2.601 2,737.60 52.32
    Background 0.011 11.05 3.32
        Sky 1.057e-11 1.11e-08 1.05e-04
        Dark Current 0.011 11.05 3.32
Total in selected region 2.611 2,748.65 54.75
Brightest Pixel (single exposure) (at 2319.51 Å) 2.209 1,162.71
Count rate entire detector 79,045.395
Buffer Time (sec) 25.30
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 61,002.023 32,108,413.090
    Background (sky+dark) 1,572.864 827,876.97
Encircled energy fraction 0.93

Instrument name: STIS
Mode: spectroscopic
Detector: NUVMAMA
Central Wavelength: 1978
Grating: [E230M] R ~ 30000
Aperture: 31X0.05NDB


Target: [point source]
Spectrum: Castelli-Kurucz Models B0I 26000 3.0
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 0.28 applied before normalization
Normalization: Renormalized to vegamag = 5.77 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 25.2