# Hubble Space Telescope Errata

Q.: In the NICMOS handbook version 2.0 page 213, the formula that converts surface flux densities:

Sv [in units of Jy/arcsec^2] = Sv [units=MJy/ster]*0.084616

This equation implies that 1 steradian=0.084616*10^6 arcsec^2, whereas I always thought 1 steradian=(206265 arcsec)^2=4.25*10^10. Could this be a TYPO?

A.: Indeed, this is a TYPO. The calculation you have made, leading to 4.25E10 arcsec**2/steradian, is the correct method.
Q.: In the web version of the Cycle 7-NICMOS Call for Proposals, Sect. 17 says: "An HST orbit normally contains 5260 minutes (depending on the declination of the target)....." Is this true????
A.: No This is a TYPO. A dash has been omitted. It should read 52-60 minutes....
Q.: In Example 1 of the exposure time calculations reported in the Instrument Handbook (version 1.0 Page 88), I cannot understand how you get a signal of C_l=4.4 electrons/sec with the parameters you specify.
A.: Indeed, the value reported in the Handbook is incorrect. The signal generated by the specified parameters is: C_l=790 electrons/sec.
Q.: Are the signals quoted in Example 2 on Page 89 of the Handbook version 1.0 (0.14 e/sec for SIII continuum filter, 0.13 e/sec for the continuum in the SIII line filter, and 0.16 e/sec for the line+continuum signal) correct?
A.: No, these are all typo's. The correct numbers are approximately 14, 13 and 16 e/sec respectively.
Q.: Are the Bandwidths of the Camera 2 Filters F187W and F205W reported correctly in Table 4.2 in the Instrument Handbook version 1.0?
A.: No, the two are exchanged. The Bandwidth of F187W is 1.75-2.0 microns. The Bandwidth of F205W is 1.75-2.35 microns; its central wavelength is 2.04 microns.