GRB030913 observations from Nyrölä Observatory

The center of HETE WXM error circle of GRB030913 imaged September 13, 2003 19:13-19:57 UT through Rc filter.

Copyright: Nyrölä Observatory, 2003



TITLE:   GRB OBSERVATION REPORT
SUBJECT: GRB030913: Optical observations
FROM:    Arto Oksanen at Nyrola Obs., Finland 

A. Oksanen on behalf of the Nyrola Observatory GRB Team reports:

Total of six 24 x 16 arcmin fields covering about the half of the HETE WXM error
circle of GRB030913 (HETE 2849) was imaged twice with the 0.4m SCT at the
Nyrola Observatory starting at September 13, 2003 19:10 UT, 2.0 hours
after the inital burst, and 21 UT under moderate sky conditions (bright moon).
 
exposure file               RA (J200.0) DEC  Mid UT  Rc
--------------------------------------------------------

6x60s    f1.fit             20 58 38 -01 57  19:13  18.0
6x60s    f2.fit             20 57 15 -02 00  19:21  18.0
6x60s    f3.fit             20 58 44 -02 12  19:29  18.0
6x60s    f4.fit             20 57 23 -02 14  19:37  18.0
6x60s    f5.fit             20 59 01 -02 20  19:49  18.0
6x60s    f6.fit             20 57 39 -02 22  19:58  18.0

6x60s    f1b.fit            20 58 49 -01 53  20:53  17.5
6x60s    f2b.fit            20 57 11 -02 00  21:05  17.5
6x60s    f3b.fit            20 58 45 -02 12  21:15  17.5
6x60s    f4b.fit            20 57 21 -02 14  21:23  17.0
6x60s    f5b.fit            20 58 51 -02 26  21:31  17.5
6x60s    f6b.fit            20 57 26 -02 29  21:39  17.5
--------------------------------------------------------

Total of 72 60s Rc-exposures were combined and visually compared to
the Digitized Sky Survey (DSS2R). 

No new objects were found to the image limits of R = 17.0 (USNOA2.0). 

We are grateful for the AAVSO International High Energy network and
the Curry Foundation to provide our CCD imager. 

Full resolution images


TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2390
SUBJECT: GRB030913: AAVSO optical observations
DATE:    03/09/19 19:09:12 GMT
FROM:    Arto Oksanen at Nyrola Obs., Finland  

Arto Oksanen, Arne Henden, Cristovao Jacques, Andrea Tasselli, 
Odd Trondal, Michel Bonnardeau and Bruce Gary report on 
behalf of the AAVSO International High Energy Network:

We have observed the GRB030913 (=H2849) error circle starting 
September 13, 2003 18:56 UT, less than 2 hours from the burst. 
The revised error circle (Donaghy et al., GCN 2388), was covered 
completly by several observers.  

The earlier larger error circle (M. Suzuki et al., GCN 2383) was 
covered by 90 percent in 7.9 hours.
 
All images vere visually checked and most images were also checked 
by software against USNOA2.0 and USNOB1.0 catalogs to detect any 
optical transients. 

No new objects were found to the image limits. At 2.85 hrs after 
the burst, no afterglow was detected to R=18 (defined by images 
marked with stars on the following summary).

Summary of all observations:

                    total    image center   limiting  from
    mid UT        exposure  RA (J200.0) DEC  mag (R) burst(h) obs
-----------------------------------------------------------------
2003-09-13T18:56    20x10s  20 58 11 -02 17    15.5   1.83    OT 
2003-09-13T19:13     6x60s  20 58 38 -01 57    18.0   2.10    AO *
2003-09-13T19:21     6x60s  20 57 15 -02 00    18.0   2.23    AO *
2003-09-13T19:29     6x60s  20 58 44 -02 12    18.0   2.37    AO *
2003-09-13T19:37     6x60s  20 57 23 -02 14    18.0   2.50    AO *
2003-09-13T19:49     6x60s  20 59 01 -02 20    18.0   2.70    AO *
2003-09-13T19:58     6x60s  20 57 39 -02 22    18.0   2.85    AO *
2003-09-13T20:53     6x60s  20 58 49 -01 53    17.5   3.77    AO
2003-09-13T21:05     6x60s  20 57 11 -02 00    17.5   3.97    AO
2003-09-13T21:15     6x60s  20 58 45 -02 12    17.5   4.13    AO
2003-09-13T21:23     6x60s  20 57 21 -02 14    17.0   4.27    AO
2003-09-13T21:30    42x60s  20 57 49 -02 22    18.0   4.39    AT 
2003-09-13T21:31     6x60s  20 58 51 -02 26    17.5   4.40    AO
2003-09-13T21:39     6x60s  20 57 26 -02 29    17.5   4.53    AO
2003-09-13T22:26    10x45s  20 57 50 -02 14    18.0   5.32    CJ 
2003-09-13T22:38    10x45s  20 57 49 -01 59    18.0   5.52    CJ
2003-09-13T22:50    10x45s  20 57 55 -02 32    18.0   5.72    CJ
2003-09-13T23:38     6x45s  20 56 32 -02 17    17.5   6.52    CJ
2003-09-13T23:50     4x45s  20 56 29 -02 01    17.5   6.43    CJ
2003-09-14T00:24     4x45s  20 59 14 -02 14    17.5   7.28    CJ
2003-09-16T02:40    18x60s  20 58 02 -02 12    20.3  57.53    BG
2003-09-17T03:55    8x900s  20 58 06 -02 35    22.7  82.82    AH
-----------------------------------------------------------------

Observer details:

AO: Arto Oksanen, Finland
    FOV: 24 x 16 arc min 
    Equipment: 0.40m SCT f/5.0, ST8XE CCD, Rc-filter

OT: Odd Trondal, Norway
    FOV: 20 x 15 arc min
    Equipment: 0.25 m f5.75, MX916 CCD, R-filter

CJ: Cristovao Jacques, Brazil
    FOV: 25 x 17 arc min 
    Equipment: 0.30m SCT f/3.0 , ST7E CCD, unfiltered

BG: Bruce Gary, Arizona, U.S.A.
    FOV: 23 x 15 arc min
    Equipment: 0.35 m SCT, AO-7 stabilizer, ST-8XE CCD, unfiltered 

AT: Andrea Tasselli, UK
    FOV: 16 x 22 arc min
    Equipment: 0.15 m Maksutov Cassegrain f/7, MX716 CCD

AH: Arne Henden, Arizona, U.S.A.
    FOV: 11 x 11 arcmin
    Equipment: 1.0m, CCD, R-filter


The AAVSO International High Energy network is grateful for a 
generous grant from the Curry Foundation and to NASA for the 
financial support for the High Energy Workshops for Amateur 
Astronomers.

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2392
SUBJECT: GRB030913, candidate afterglow observations
DATE:    03/09/20 18:09:43 GMT
FROM:    Arne A. Henden at USNO/USRA  

A. Henden (USRA/USNO) and A. Oksanen (Nyrola Obs.) report
on behalf of the AAVSO International High Energy Network:

We have examined the early-time R-band images from Nyrola
Observatory near the location of the proposed optical
transient of Guziy et al. (GCN 2391). A stack of the
f5.fit and f5b.fit composite images, giving an effective
mid-exposure time of t_0 + 3.5hrs, does not convincingly
show any object at the position shown in the Guziy et al.
finding chart.  A jpeg copy of the stack can be found at
http://nyrola.jklsirius.fi/grb/grb030913/f5f5b.jpg
Based on nearby USNO-B stars, we can place a limiting
magnitude of R=19.5 for any object at this location.
Combined with the V=20.9 at t_0 + 4.25day measure of
Guziy et al., this would give an unrealistic decay slope
for a typical GRB.  Either this object is unrelated to the
afterglow, or the afterglow increased in brightness after 4hrs.

The AAVSO International High Energy network is grateful for a
generous grant from the Curry Foundation and to NASA for the
financial support for the High Energy Workshops for Amateur
Astronomers.
Field of the
suspect imaged at
t_0 + 3.5 hrs
The combined 720 s R-band exposure of the suspect field (6x10 arc min, North up)
3.5 hours after the burst. Click the image for full resolution.

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