Version 4, Aug 15, 2017.

This tool gives optical-to-infrared background estimates for observations from the Earth-Sun L2 Lagrangian region, the future site of the James Webb Space Telescope (JWST) and Euclid. Backgrounds as seen from Earth's orbit are also available. The service can also be accessed by an HTTP program interface .

The estimates for zodiacal brightness depend on the date. The user may select "Day" (of year), or "In Viewing Zone", which will give the median value for times in the year that the object is in a typical spacecraft viewing zone. See the Help page for details.

NOTE: Version 4 contains a newer estimate of zodiacal light and a more precise model for galactic starcounts. See the Help page for details. Version 1 can be accessed from the button (single location) or with table column "obsver" set to "1" (table upload).

Coordinate/Object:

Wavelength:                    (0.5 to 1000.0 microns)

Year:                    (see below)

Day (1 to 366)     In Viewing Zone

Observing Location:        Earth-Sun L2        Earth

Note: Dates for L2 are Day 274, 2018 (Oct 1) to Day 120, 2029 (Apr 30). The zodiacal value depends on the location obtained from a spacecraft ephemeris, currently a prediction for JWST limited to that time range.

Version of code:        Version 4        Version 1

Coordinate Examples:    19h17m32s 11d58m02s Equ J2000   |   46.5377 -0.2518 gal   |  M 31  | 222.9824 -60.2877 | Default Coordinate System:  Equatorial J2000

Table format and examples