[vsnet-grb-info 2950] Oddball GRB 060218, transient or GRB?

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4787
SUBJECT: Oddball GRB 060218, transient or GRB?
DATE:    06/02/19 21:49:58 GMT
FROM:    Neil Gehrels at GSFC  <gehrels at gsfc.nasa.gov>

N. Gehrels (NASA-GSFC) on behalf of the Swift team:

We point out that GRB 060218 (Cusumano et al. GCN 4775) is a 
strange event. It has  
- a gamma-ray light curve that is flat and a soft spectrum 
(Barbier et al. GCN 4780)
- an X-ray light curve with a long, slow rise and gradual 
decline (Cusumano et al. GCN 4786)
- an optical light curve with brightening after 10 hours 
(Marshall et al. GCN 4785).  
These characteristics are unlike previous GRBs.

It has properties that are also atypical of a transient:
- it is far off the galactic plane (b = -32.9 deg) and 
far away from the bulge (l = 166.9 deg)
- there is a possible association (Mirabel GCN 4783) with 
a galaxy in the SDSS pre-burst field (Cool et al. GCN 4777).

Further observations are warranted.