Zero Points
You are here
The following table lists zero points for NICI in several filters. A zero point is defined as the magnitude of an object that would yield 1 ADU/sec at an airmass of 1. They depend on instrument and telescope transmittances as well as detector electronics.
All values here were computed from observations of the near-infrared standard S372-S on 2008 Jan 31, with the H50/50 beamsplitter.
Filter | Center wavelength (µm) |
Zero point magnitude (Holmes, red) |
Zero point magnitude (Watson, blue) |
Sky background (mag/arcsec) |
CH4 H 4% S |
1.578 |
21.4 |
||
CH4 H 4% L |
1.652 |
21.4 |
||
CH4 H 1% S |
1.584 |
19.7 |
||
CH4 H 1% L |
1.627 |
20.0 |
||
J |
1.27 |
22.0 |
||
H |
1.65 |
23.5 |
||
Ks |
2.17 |
23.1 |
||
Br-gamma |
2.1686 | |
19.9 |