GRB 050805A
GCN Circular 3767
Subject
GRB050805a: MASTER optical candidat
Date
2005-08-05T20:48:55Z (20 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski,
E.Gorbovskoy, A.Krylov, G.Borisov, V.Vladimirov, Krushinski V.
Sternberg Astronomical Institute, Moscow Union "Optic"
MASTER (http://observ.pereplet.ru) responded to GRB 050801 (Swift trigger
149118). The first image was 35 sec after Notice Time and 113 sec
after SWIFT
probable GRB050805
detection (19:14:00.34 UT, GCN3766) under the
evening sky near the horizont. The first image was saturated.
The first not saturated image was at 720 sec after GRB time (exposition 1 s).
Optical limit is about 12.5 (unfiltred close to R).
On next images we see new variable faint source 14.5 inside Swift error
box
wich disapear after .
alpha = 22 04 40.91
delta = +29 51 48.1
error is about 2''.
The JPG-images are available at
http://observ.pereplet.ru/images/GRB050805/1.jpg .
This work is supported by RFFI 04-02-16411 grant.
This message can be cited.
Mailto: lipunov@sai.msu.ru
GCN Circular 3776
Subject
GRB050805a : Null detection report
Date
2005-08-06T12:33:27Z (20 years ago)
From
Eran Ofek at Tel Aviv U. <eran@wise1.tau.ac.il>
E. O. Ofek, Y. Lipkin (Wise observatory, TAU) report:
We have observed the error box of the of the Swift trigger 149118
(Cummings et al. 2005, GCN 3766; designated as GRB 050805a by Lipunov et
al. GCN 3767), using the Wise observatory 1m telescope + Tek CCD camera,
starting at 2005, Aug 05th, 21:50 UTC.
Comparing a 300 sec R-band image which we obtained (mid exposure time
0.15851 days after the Swift-BAT trigger) to the POSS2 R-band image,
we did not detect any new source in the 2" error circle of the optical
transient that was reported by Lipunov et al. (GCN 3767).
The limiting magnitude of our image was R=19.5.
If we understood correctly the message of Lipunov et al., then
our observations took place 2.637 hrs after theirs.
If Lipunov et al. indeed detected the OT, and further
assuming a power-law decay, this time difference would imply a
decay-rate index that is larger than 2.08.
We note that according to GCN 3766, GRB050805a
is probably not a real GRB.
GCN Circular 3868
Subject
GRB050805a: MASTER optical candidat
Date
2005-08-25T02:15:24Z (20 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
V. Lipunov, V.Kornilov, N.Tyurina, A.Belinski,
E.Gorbovskoy, D.Kuvshinov, A.Krylov, G.Borisov, V.Vladimirov, Krushinski
V.
Sternberg Astronomical Institute, Moscow Union "Optic"
MASTER (http://observ.pereplet.ru) responded to GRB 050824 (Swift
trigger 151905). The first image was 764 sec after
SWIFT GRB050824 detection under the
not very good weather condition.
We see OT J. Gorosabel (GCN 3865) with m = 17.5 (unfiltered close to R,
exp. 45 sec) on 2-3 sigma level.
On summ of 9 images from 19.5 up to 28.5 minut after GRB Time (23 12 16.00
UT) m= 18.0 on 5 sigma.
UT After GRB time m
23 25 00 764s 17.9
23 31 44 19.5min - 28.5 min 18.3
23 31 44 19.5min - 37.75 min 18.8
The JPG-image of the summ will be available at
http://observ.pereplet.ru/images/GRB050824/1.jpg .
The reduction is continuing.
This work is supported by RFFI 04-02-16411 grant.
This message can be cited.
Mailto: lipunov@sai.msu.ru
GCN Circular 4090
Subject
GRB050805A: Rc optical observations
Date
2005-10-12T19:46:11Z (20 years ago)
From
Graziella Pizzichini at IASF/CNR,Bologna <pizzichini@bo.iasf.cnr.it>
GRB050805A: optical observations
D. Nanni, (INAF/Osservatorio di Roma), F. Terra (CRATI scrl, and Cosenza
University), C. Bartolini, G. Greco, A. Guarnieri, A. Piccioni (Bologna
University), S. Marinoni, A. De Blasi (INAF/Osservatorio di Bologna) and
G. Pizzichini (INAF/IASF, Bologna)
report:
We observed the error box of possible GRB050805A (Swift trigger
149118) with the 152 cm Loiano Telescope and the BFOSC camera system in
good sky conditions.
We obtained the following images, all of them in the Rc filter:
Start time (UT) Duration
(min)
050805 22:24:05 10
050805 22:44:13 10
050805 23:09:17 20
050805 23:34:36 20
050806 02:07:02 20
050806 02:29:00 20
We do not detect the optical candidate cited by Lipunov et al., GCN 3767.
At its location the 3 sigma magnitude limit in our coadded images is 22.5 .
The coadded images and the observation log will be posted in our
public directory from where they can be retrieved by sftp
using hostname: ermione.bo.astro.it, username: publicGRB, password:
GRB_bo, directory: GRB050805A.
[GCN OPS NOTE(12oct05): The SUBJECT line was changed from "040825A" to "050805A".]