JWST Continuous Viewing Zone (CVZ)
JWST has two small continuous viewing zones (CVZs) centered at each of the ecliptic poles.
Because JWST operates in an ecliptic coordinate framework, there are 2 small continuous viewing zones (CVZs) centered at each of the ecliptic poles (see Figure 6). The 85° solar exclusion zone then determines the radius of the allowed CVZs to be essentially 5°, although any observation approaching the 85° limit will have additional limitations due to safety considerations.
Figure 1. An all-sky map showing the location of the CVZs relative to galactic extinction
Magenta lines show the ecliptic plane (b = 0°) and latitudes b = ±30°, ±60°, and ±85° vs. equatorial coordinates (RA and Dec). The b = ±85° ovals enclose the JWST CVZs, the areas within 5° of the ecliptic poles (b = ±90°). The background color map shows Galactic extinction measured by Schlegel, Finkbeiner, and Davis (1998). Note the higher extinction and SMC visible within the southern CVZ.
In standard J2000 equatorial coordinates, the CVZs are centered at the following coordinates:
N-CVZ: 18h00m00.00000s +66°33'38.5520" (or 270.00000000° +66.56070889°)
S-CVZ: 6h00m00.00000s −66°33'38.5520" (or 90.00000000° −66.56070889°)
The S-CVZ encompasses a portion of the Large Magellanic Cloud.
References
Schlegel, D. J., Finkbeiner, D. P., Davis, M. 1998, ApJ, 500, 525
Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds