Extensive reading for Are the dispersion directions of the prism and the grating in Hubble WFC3 UVIS G280 perpendicular? Can we call this a "grism"? With cross-disparsion? led me to Instrument Science Report WFC3 2003-02; WFC3 UVIS Filters: Measured Throughput and Comparison to Specifications.

Table 1: "UVIS Filter Performance Specifications from Version D JPL Spec or CEI" lists near the bottom

Fnumber  Fname   Lam0   FWHM  lam -50 ... lam +50 ... Description
-------  -----  ------  ----  -------     -------     -----------
UVIS 47  G200   2775.0  1850    1800  ...   3650  ...   UV prism

Question: What is Hubbles WFC3 "UVIS 47 G200" filter? Is it just a prism or is it a combination of a prism and a filter?

What is it used for?

How can I find an example of how it has been used in practice?


I believe that is a typo. In Tables 4 and 5 of the same document, "UVIS 47" is listed as "g280", which is the grism you are curious about.

A perusal of several other HST documents (e.g., various Wide Field Camera 3 Instrument Handbooks) turns up no mention of a "G200" element, and searches of the HST archive turn up nothing if "G200" is entered in the "Filter/Grating" field. (Entering "G280" turns up observations with that grism.)

  • 1
    $\begingroup$ nice detective work, thanks! $\endgroup$
    – uhoh
    Oct 15 at 14:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.