Dear All, In a moment, Dan Reichart will circulate empirical estimates of the expected brightness of GRB990123 tonight in a number of filters. The afterglow is expected to be so bright that multiwavelength observations are probably a priority -- extending into the v-, b-, and perhaps even the u-bands. NIR observations would also be very important in determining the spectral and temporal behavior of this burst. Such observations might be attempted just before dawn, when optical observations would not be as effective. Lastly, the optical afterglow is so bright that we might want to consider whether taking the observations in such a way that detection of or limits on any optical variability could be derived. Good observing! With warm best wishes, Don APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 22 in the apo35-grb archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-grb/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-grb@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO