GRB 011211: BVRi-band photometry 
NUMBER:  1194
SUBJECT: GRB 011211 : BVRi-band photometry
DATE:    01/12/12 15:54:51 GMT

B. L. Jensen, H. Pedersen, J. Hjorth, R. Michelsen (U. of Copenhagen), T. Grav, M. W. Hansen (U. of Oslo), J. U. Fynbo (ESO), M. Weidinger (U. of Aarhus), M. I. Andersen (U. of Oulu) and J. Gorosabel (DSRI) report:

"We have performed aperture photometry of the afterglow candidate for GRB 011211 reported in GCN#1191 (Grav et al.), and obtain the following results based on a preliminary photometric calibration:

For USNO-star U0675_11427359 at RA,Dec (J2000) = (11:15:19.00, -21:58:04.9) we obtain:

I = 17.07, R = 17.90, V = 18.18, B = 18.65

For the afterglow candidate we measure: 

Tel.      Date (UT)   exp    filter  mag.
=========================================
NOT-2.5m  Dec.12.22   900s     R    20.07
NOT-2.5m  Dec.12.28   300s     B    21.41
NOT-2.5m  Dec.12.28   300s    g-i   20.09
NOT-2.5m  Dec.12.29   300s     V    21.14

DK-1.5m   Dec.12.28  4200s     R    20.12
DK-1.5m   Dec.12.36   300s     V    21.21

Conservative errors on the absolute photometry is ~0.15 mag, due to lack of precise calibration. Errors relative to the USNO-star are around a few percent.

Further images will be made available at http://www.astro.ku.dk/~brian_j/grb/grb011211 "

 

 

Click for larger images

Finding chart for GRB 011211. R-band 3x300s exposure taken with the Nordic Optical Telescope (NOT) on 2001, December 12.2.
The OT is marked at the centre of the image, surrounded by the XMM-Newton 10" error-circle reported by Santos-Lleo et al. (GCN#1192).

Left: 300s B-band exposure taken with the NOT on 2001, Dec.12.2
Right: 300s V-band exposure taken with the NOT on 2001, Dec.12.3

 

 

 

 

GRB 011211: Optical observations 
NUMBER:  1191
SUBJECT: GRB 011211 : Optical observations: Likely Afterglow
DATE:    01/12/12 10:15:57 GMT

T. Grav, M. W. Hansen (U. of Oslo), H. Pedersen, J. Hjorth, R. Michelsen, B. L. Jensen (U. of Copenhagen), M. I. Andersen (U. of Oulu), J. Gorosabel (DSRI), J. U. Fynbo (ESO) report:

We have obtained optical follow-up observations of the SAX error circle of GRB 011211 (cf. GCN ##1188,1189) with the ALFOSC on the 2.56-m NOT and with DFOSC on the Danish 1.5m on La Silla starting at about 12.2 December 2001 UT. In R-band images a new point source, not visible in the DSS-2 (red), is detected at RA (J2000) = 11:15:17.98, Dec(J2000) = -21:56:56.2 with an estimated error of +- 1". The magnitude is about R = 19. Given the proximity to the refined SAX WFC position and its absence in DSS, the source is likely the afterglow of GRB 011211.

The above findings are preliminary. More details will be reported later. Images will be made available at http://www.astro.ku.dk/~brian_j/grb/grb011211

 

2x600s R-band exposure, taken with the Danish 1.54m telescope at La Silla.

 

Last updated on December 12 2001, by Brian Lindgren Jensen