February 22, 2006: The optical afterglow and underlying supernova for GRB060218 continues to brighten and has generated a lot of interest in the scientific community. It is well positioned in the early evening sky for professional and amateur monitoring. The latest coordinates are:
R.A.: 03:21:39.71 Decl.: +16:52:02.1 J2000
Please observe with CCD V or Rc filters, and use long enough exposures to be able to reach S/N=50 on the object, which should be around V=16-19. Note that unfiltered observations are not very useful for GRB afterglows, which usually require the combination of observations from many different sources.
Rapid time series is not necessary, but if you can get multiple images in a single filter with S/N=50, or a V/R pair per night, that won't hurt.
A finding chart has been posted at this URL:
http://www.aavso.org/observing/programs/hen/grb060218.png
Field photometry will be posted to the AAVSO High Energy Network and AAVSO Photometry discussion groups when it becomes available.
The burst, which occurred at 03:34:30.97UT on 060218, was detected by the Swift satellite. The optical afterglow was discovered by its UVOT instrument (GCN 4775). Neil Gehrels pointed out in GCN 4787 that this burst was a very unusual event. The X-ray light curve can be seen at: http://www.merate.mi.astro.it/~moretti/lc_060218.gif
Mirabal and collaborators (GCN 4792) measured a red shift of z=0.0331, making it a very nearby GRB. A host galaxy can be seen on SDSS images. Soderberg and collaborators (GCN 4794) report that there was an immediate detection of a radio source.
Probably most importantly, Masetti and collaborators (GCN 4803) report that a supernova spectrum was emerging only 3 days after the burst.
Most researchers now believe that the supernova (designated SN 2006aj, see IAUC 8674) is still rising to maximum. It is currently about 19th magnitude, but should increase to V=16-17 in the next week or two, well within the range of AAVSO observers.
In GCN 4777, Cool et al. indicate that images, photometry and astrometry are available at: http://mizar.as.arizona.edu/~grb/public/GRB060218
This special notice was compiled by: A. Henden & A. Price
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