GRB 090424
GCN Circular 11883
Subject
Comparison of ICSP VLF observation of GRB 090424 with satellite observations
Date
2011-04-05T11:09:52Z (15 years ago)
From
Sandip K. Chakrabarti at S.N. Bose Nat. Centre for Basic Sci. <chakraba@bose.res.in>
Sushanta K. Mondal (ICSP), Sandip K. Chakrabarti (S. N. Bose Centre and ICSP),
Asit Choudhury (ICSP, Malda branch), Achintya Chatterjee (ICSP, Malda Branch),
and D. Bhowmick (ICSP)
Indian Centre for Space Physics observed the ionospheric perturbation
due to GRB 090424 (GCN No. 9316) through monitoring VLF signals from various
transmitters.
The final analysis with corrected time stamp
(http://www.bose.res.in/~chakraba/grb090424.html) suggests
that VLF signals were spreaded out for few seconds due to ionospheric effects.
GCN Circular 9504
Subject
GRB 090424: WSRT Radio Observations
Date
2009-06-12T04:00:08Z (17 years ago)
From
Alexander van der Horst at NASA/MSFC <Alexander.J.VanDerHorst@nasa.gov>
A.J. van der Horst (NASA/MSFC/ORAU) and A.P. Kamble (University of
Amsterdam) report on behalf of a large collaboration:
"We observed the position of the GRB 090424 afterglow with the Westerbork
Synthesis Radio Telescope at 2.3 GHz at May 4 19.91 UT to May 5 3.34 UT,
and at 4.9 GHz at May 23 15.97 to 21.45 UT, i.e. 10.39 and 29.19 days
after the burst (GCN 9223) respectively.
We do not detect a radio source at the position of the optical counterpart
(GCN 9223). The three-sigma rms noise in the map around that position is
168 microJy per beam at 2.3 GHz and 132 microJy per beam at 4.9 GHz. The
formal flux measurement for a point source at the position of the optical
counterpart is 47 +/- 56 microJy and 84 +/- 43 microJy at 2.3 and 4.9 GHz
respectively.
We would like to thank the WSRT staff for scheduling and obtaining these
observations."
GCN Circular 9484
Subject
GMRT observation of GRB 090424 afterglow
Date
2009-06-03T14:37:33Z (17 years ago)
From
Atish Kamble at U. of Amsterdam <A.P.Kamble@uva.nl>
Atish Kamble (University of Amsterdam), Sabyasachi Pal (NCRA/TIFR),
A. J. van der Horst (NASA/MSFC), D. Bhattacharya (IUCAA,Pune),
R. Wijers (University of Amsterdam), C. H. Ishwara Chandra
(NCRA/TIFR), Evert Rol (University of Amsterdam) report on behalf
of a larger GRB collaboration :
The Giant Metrewave Radio Telescope (GMRT), India observed the field of
GRB090424 (GCN 9223, GCN 9260) on 23 May 2009 (between 11.0 UT
and 15.0 UT i.e. about 30 days after the burst) at 1280 MHz using a
bandwidth of 32 MHz. The radio transient was not detected down
to a 3-sigma upper limit of 141 microJy at the source location.
We thank the GMRT and the National Centre for Radio Astrophysics (NCRA)
staff. This TOO was done under the GMRT Director's Discretionary Time.
GMRT is run by NCRA-TIFR, Pune (INDIA).
This message may be cited.
GCN Circular 9320
Subject
GRB 090424: optical observations
Date
2009-05-04T00:21:25Z (17 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V. Rumyantsev, K. Antoniuk (CrAO), A. Pozanenko (IKI) report on behalf of
larger GRB follow-up collaboration:
We observed the afterglow (Cannizzo et al. GCN 9223; Yuan GCN 9224) of the
Swift GRB 090424 (Trigger 350311; Cannizzo et al., GCN 9223) in R filter on
Apr. 24 (18:25:36 -- 19:23:38) and Apr. 26 (19:57:14 -- 21:01:01) with
AZT-11 telescope of CrAO. We detect the afterglow in combined images of
both epochs. Astrometry of the afterglow is RA(J2000): 12 38 05.1
Dec(J2000): +16 50 14.72 with uncertainty of 0.5 arcsec.
Preliminary photometry of combined images is based on USNO-B1.0
1068-0228255 star RA=12:38:02.33 Dec=+16:51:10.0 is following:
T0+ Filter, Exposure, mag., err.
(d) (s)
0.1972 R 20x180 19.27 +/-0.06
2.2628 R 20x180 21.0 +/-0.2
The photometry is contaminated with possible host galaxy (Evans et al. GCN
9226).
The combined image of the Apr. 24 observation can de found at
http://grb.rssi.ru/GRB090424/GRB090424_AZT-11_R.gif
GCN Circular 9316
Subject
ICSP VLF observation of GRB090424 from four receivers
Date
2009-05-01T13:25:00Z (17 years ago)
From
Sandip K. Chakrabarti at S.N. Bose Nat. Centre for Basic Sci. <chakraba@bose.res.in>
ICSP VLF observation of GRB090424 from four receivers
Sandip K. Chakrabarti (S. N. Bose Centre and ICSP), Sushanta K. Mondal (ICSP),
Asit Choudhury (ICSP, Malda branch), Achintya Chatterjee (ICSP, Malda Branch),
Narendra N. Patra (Univ. Pune) and D. Bhowmick (ICSP)
Three ICSP VLF receivers clearly observed the effects of GRB090424
(GCN#s 9223, 9230) on the ionosphere simultaneously. The subflare point
(16.8d N , 123.76d E) being closer to eastern India the signal was prominent.
Two receivers were kept at Kolkata (22.5N, 88.5d E) at sixteen kilometers
(~ 10 miles) apart, while a third receiver was kept at Malda (25d N, 88d E)
which is about 200 miles away. All the three receivers detected the GRB right
after triggering and the correlation of the signals were found excellent for
about ~100 seconds. Before the triggering, the correlation was poor. The signal
from a fourth ICSP receiver at Pune (~1000 miles from Kolkata) in western
India (18.5d N, 74d N) was very poor.
A comparison of the smoothed signals can be found in allthree.jpg in
http://www.bose.res.in/~chakraba/grb090424-1.html. This message may be cited.
GCN Circular 9313
Subject
GRB 090424, SMARTS optical/IR afterglow monitoring
Date
2009-05-01T03:00:53Z (17 years ago)
From
Bethany Cobb at UC Berkeley <bcobb@astro.berkeley.edu>
B. E. Cobb (UC Berkeley) reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained
optical/IR imaging of the error region of GRB 090424 (GCN 9223, Cannizzo
et al.) over nine epochs between ~0.5 and 5.6 days post burst. In our
first epoch of imaging, total summed exposure times amounted to
15 minutes in I and V and 12 minutes in J and K. All later epochs had
total summed exposure times of 36 minutes in I and 30 minutes in J.
The optical afterglow of GRB 090424 (e.g. GCN 9223, Cannizzo
et al. & GCN 9224, Yuan et al.) is observed to fade steadily in our
imaging with no indication of a jet break between ~0.5 and 5.6 days
post-burst. The combined light of the afterglow and the underlying galaxy
fades with a decay rate of alpha = -0.72 (where afterglow flux is
proportional to t^alpha). Assuming that the galaxy has an intrinsic
magnitude of I=21.6 (based on the SDSS i and r values and the Lupton 2005
transformation equations), then the afterglow's true decay rate is
alpha = -1.2 over these epochs.
The afterglow + host galaxy photometry is measured as follows (no
correction has been made for Galactic extinction):
mid-exposure
time (days
post-burst) I mag J mag V mag K mag
-------------------------------------------------------------------
0.45031 19.42+/-0.04 18.31+/-0.06 20.61+/-0.04 16.38+/-0.05
0.50291 19.45+/-0.04 18.11+/-0.04 ... ...
0.57498 19.61+/-0.04 18.22+/-0.05 ... ...
0.62815 19.70+/-0.04 18.23+/-0.05 ... ...
1.53459 20.45+/-0.05 19.18+/-0.08 ... ...
2.49012 20.92+/-0.05 19.61+/-0.11 ... ...
3.51877 20.99+/-0.05 19.53+/-0.09 ... ...
4.56909 21.24+/-0.08 > 19.7 ... ...
5.56135 21.31+/-0.10 > 19.7 ... ...
(Optical photometry is calibrated against Landolt standard stars
and IR photometry is calibrated against 2MASS stars in the field.)
GCN Circular 9305
Subject
GRB 090424: YNAO-GMG observations
Date
2009-04-30T11:10:12Z (17 years ago)
From
Jirong Mao at Yunnan Obs <jirongmao@ynao.ac.cn>
J. Mao (YNAO & INAF-OAB), G. Cha and J. Bai (YNAO) report on behalf of the GMG group:
We observed the optical counterpart of GRB 090424 (Cannizzo et al., GCN 9223) using
one 2.4-m telescope located at Gao-Mei-Gu (GMG) about 40 minutes after the trigger and
obtained the following magnitudes:
Start UT Exposure Filter mag err
-------------------------------------------------
14:53:41 10 sec R 17.51 0.02
14:56:41 30 sec B 18.50 0.03
15:01:22 30 sec V 18.57 0.02
15:03:55 20 sec I 17.68 0.02
17:26:58 75 sec R 18.89 0.04
We continued our observations of GRB 090424 in R band started at 13:42:00 UT on April
25, 2009. After 20 minutes of exposure time, we obtained the magnitude R=20.59 +/-
0.07 mag.
All the calibrations were processed by nearby SDSS stars.
The telescope is charged by Yunnan Observatory (YNAO), Chinese Academy of Sciences.
This message might be cited.
GCN Circular 9278
Subject
GRB 090424 : Multiband Optical observation from Nainital
Date
2009-04-28T19:35:04Z (17 years ago)
From
Rupak Roy at ARIES <rupakroy1980@gmail.com>
Rupak Roy, Brajesh Kumar, S. B. Pandey and Brijesh Kumar (ARIES,
NainiTal, India, on behalf of larger Indian GRB collaboration).
We performed BVRI photometric observation of Swift GRB 090424
(Cannizzo, J. K. et al., GCN 9223) on 24th April, 2009 at 16.7 hrs UT,
under moderate sky conditions,
using 1.04 m Sampurnanand Optical telescope at ARIES, Nainital. The
same field was again observed on next day, about 29 hrs after the
burst in R and I bands.
Fading nature of the afterglow is clearly visible in all bands. The
R_c and I_c band magnitudes of OT, with respect to nearby USNO-B1
stars, are 18.5 +/- 0.05 and 17.8 +/-
0.06 respectively, measured 2.67 hrs after the burst. Further analysis
is under progress.
GCN Circular 9275
Subject
GRB 090424: Continued R-band monitoring
Date
2009-04-28T02:18:53Z (17 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
M. Im, Y. Jeon, W. Park, I. Lee (CEOU/Seoul National Univ),
Y.-B. Jeon (KASI) and Y. Urata (NCU) on behalf of EAFON team.
We continued our follow-up observation of GRB090424
(Cannizo et al. GCN 9223) in R using the 1.0m telescope
at Mt. Lemmon (Arizona, US) operated by the Korea Astronomy
Space Science Institute.
The R-band imaging started at 2009 April 27, 02:57:33 UT.
The mid-point of the R-band obseravation is April 27,
03:45:21 UT (61.55 hrs after the burst).
From a stacked image of 20 frames (3 min exp. each),
we clearly detect the afterglow at R=21.7 +- 0.3 mag.
Note that this value includes the flux (R ~ 22.2 mag)
of the host or foreground galaxy at the location of
the GRB noted by Evans et al. (GCN 9226).
The trend of the fading, corrected for the galaxy light
contamination, is consistent with a steep decay of flux
reported earlier (Im et al. GCN 9253).
The photometry was calibrated against USNO-B1 stars in
the vicinity of GRB.
Mid-point Rmag Rmag
(hrs after burst) (excluding the galaxy light)
-----------------------------------------------------
14.97 19.9+-0.14 20.0
37.45 21.0+-0.17 21.4
61.55 21.7+-0.30 22.8
We thank the LOAO operator, I. Baek for her assistance for this
observation.
GCN Circular 9270
Subject
GRB 090424: Suzaku WAM observation of the prompt emission
Date
2009-04-27T14:14:03Z (17 years ago)
From
Yoshitaka Hanabata at Hiroshima U <hanabata@hep01.hepl.hiroshima-u.ac.jp>
Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa(Hiroshima U.),
K. Kono, E. Sonoda, M. Yamauchi, N. Ohmori, H. Hayashi,
K. Noda, A. Daikyuji, Y. Nishioka (Univ. of Miyazaki),
M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA),
W. Iwakiri, M. Tashiro, Y. Terada, A. Endo, K. Onda,
T. Sugasahara (Saitama U.), Y. Urata (NCU),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo),
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), Y. E. Nakagawa,
T. Tamagawa (RIKEN), S. Hong (Nihon U.), N. Vasquez (Tokyo Tech.),
on behalf of the Suzaku WAM team, report:
The long GRB 090424 (Swift/BAT trigger #350311 ; Cannizzo et al., GCN
9223) triggered the Suzaku Wide-band All-sky Monitor (WAM) which
covers an energy range of 50 keV - 5 MeV at 14:12:09.216 UT (=T0).
The observed light curve shows a multi-peaked structure starting at
T0-1 s, ending at T0+12 s, with a duration (T90) of about 4.18
seconds.
The fluence in 100 - 1000 keV was 1.36 (-0.10, +0.28) x10^-5 erg/cm2.
The 1-s peak flux measured from T0 was 12.6 (-0.9, +1.6) photons/cm2/s
in the same energy range.
Preliminary result shows that the time-averaged spectrum from T0-1 s
to T0+12 s is fitted by a power-law with exponential cutoff model:
dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
alpha 0.92 (-0.77, +0.66), and
Epeak 250 (-83, +41) keV (chi^2/d.o.f. = 18.9/27).
Due to the high counting rate of this GRB, a 3% systematic error
was added for low energy channels.
We note that this GRB came from the WAM 2 direction,
which has a large uncertainty ~40 % in the absolute flux.
The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
GCN Circular 9260
Subject
Detection of bright radio afterglow of GRB 090424 with the VLA
Date
2009-04-26T18:29:16Z (17 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on
behalf of a larger collaboration:
"We used the Very Large Array to observe the field of view toward the
GRB 090424 (GCN 9223) at a frequency of 8.46 GHz on 2009 Apr 26.09 UT.
We detected a bright radio afterglow at the UVOT position (GCN 9223).
The GRB radio flux density is 673 +/- 39 uJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 9253
Subject
GRB090424: R-band detection (37.5 hrs post-burst), jet break?
Date
2009-04-26T11:30:29Z (17 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
M. Im, W. Park, Y. Jeon, I. Lee (CEOU/Seoul National Univ),
Y.-B. Jeon (KASI) and Y. Urata (NCU) on behalf of EAFON team.
We continued the follow-up observation of GRB090424 (Cannizzo et al.
GCN 9223) in BVR using the 1.0m telescope at Mt. Lemmon (Arizona, US)
operated by the Korea Astronomy Space Science Institute.
The R-band imaging started at 2009 April 26, 03:11:23 UT.
The mid-point of the R-band obseravation is April 26,
03:39:43 UT (37.45 hrs after the burst).
From a stacked image of 13 frames (3 min exp. each),
the afterglow is visible at R=20.96 +- 0.17 mag, suggesting
a significant fading occurred since last night (Im et al. GCN 9248),
more than the expected amount of fading with the power-law index
of 0.71 reported earlier (Urata et al. GCN 9247). This suggests that
jet break might have occured. The afterglow is also visible in
B- and V-bands.
The photometry was calibrated against USNO-B1 stars in the vicinity.
We thank the LOAO operator, J. Yoon for his assistance for this
observation.
GCN Circular 9252
Subject
GRB 090424: MASTER-Net prompt optical limit
Date
2009-04-25T20:29:42Z (17 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina,
D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov
Sternberg Astronomical Institute, Moscow State University
K.Ivanov, S.Yazev
Irkutsk State University
A. Tlatov, A.V. Parhomenko,
Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinski, I.Zalognikh, T.Kopytova
Ural State University, Kourovka
There are 6 MASTER Very Wide Field cameras located at Kislovodsk and Irkutsk
with common FOW = 6000 square degrees (http://observ.pereplet.ru/).
One of the two MASTER Very Wide Field Cameras located at Irkutsk
(D=50 mm, 2x1000 square degrees, 11 Mpx, 72" per pix in binning regime) has
observed UVOT error box (Cannizzo et al., GCN 9223) with 1s exposure befoure,
during and after GRB Time without time gap between images.
The error box is near at the center of our FOW.
Our unfiltered images are calibrated relative to Tycho stars (V) and very
close to V band.
The magnitude limit of the each emage is ~8 m at the center of FOW (some
cloudy on the sky). The limit of coadded six images ~ 9 m.
We do not detect OT.
Our observations results:
----------------------------------------------------------------------
Fermi GRB Trigg.* Exposure Mag Limit Optical Flux Coadd?
time (sec) (sec) (m) (erg/sm^2 s)
----------------------------------------------------------------------
-2 1 8.1 1.3x10^-8 No
-1 1 8.1 1.3x10^-8 No
0 1 8.0 1.4x10^-8 No
+1 1 8.0 1.4x10^-8 No
+2 1 8.0 1.4x10^-8 No
+3 1 7.9 1.5x10^-8 No
+4 1 8.0 1.4x10^-8 No
+5 1 8.0 1.4x10^-8 No
-60 : +120 1 ~8 ~1.4x10^-8 No
-6 6 8.9 7.0x10^-9 Yes
+0 6 8.7 7.3x10^-9 Yes
+6 6 8.8 7.2x10^-9 Yes
+12 6 8.9 7.0x10^-9 Yes
-60 60 9.7 3.0x10^-9 Yes
0 60 9.7 3.0x10^-9 Yes
60 60 9.5 3.5x10^-9 Yes
-----------------------------------------------------------------------
*Fermi GBM Trigger Time = 14:12:08.67 (Connaughton, GCN 9230) 1%
coincident with our start zero image time.
1). the optical fluence during GRBurst is limited by
0 up to +6 s ~<= 1 x 10E-7 erg/cm^2
0 up to +60 s <= 5 x 10E-7 erg/cm^2
including total absorbtion 1 magnitude in V band.
(The absorption column density NH = (0.20 +/- 0.01) x10^22 cm^-2
from Swift XRT spectrum data, Margutti, GCN 9237).
The event fluence (8-1000 keV) in this time interval is
(5.2 +/- 0.1)E-05 erg/cm^2 (Connaughton, GCN 9230).
So:
2).
Optical-Fluence(6s)/Gamma-Fluence (8-1000 keV) ~ < 1/500
Optical-Fluence(60s)/Gamma-Fluence(8-1000 keV) ~ < 1/100
The same ratio for GRB080319B is
Optical-Fluence/Gamma-Fluence(8 - 1000 keV) ~ 1/140
(Naked Eye GRB, Racusin, Karpov et al., Nature, vol.455, 183, 2008).
The light curve and film of our observations is available at
http://observ.pereplet.ru/images/GRB090424/GRB090424.html
The reduction is continued.
The message may be cited.
mailto: lipunov@sai.msu.ru
GCN Circular 9250
Subject
GRB 090424: WHT ISIS spectroscopy
Date
2009-04-25T17:23:03Z (17 years ago)
From
Klaas Wiersema at U of Leicester <kw113@star.le.ac.uk>
K. Wiersema (Leicester), A. de Ugarte Postigo (ESO) and A. Levan (Warwick)
report on behalf of a larger collaboration:
We observed the afterglow of GRB 090424 (Cannizzo et al, GCN 9223) with
the ISIS spectrograph on the William Herschel Telescope at the
Observatorio del Roque de los Muchachos on La Palma, ~8 hours after burst.
In the spectrum we find several lines, among others the Mg II doublet
(with restframe EW > 1 A of the 2796 line), Fe II, Na I. Through these we
confirm the redshift of z=0.544 found by Chornock et al (GCN 9243).
Continuum is detected up to at least 3200 A, giving an upper limit to the
GRB redshift of 1.6, consistent with the emission and absorption redshift
of 0.544.
We thank the staff of the WHT, in particular O. Vadivescu, for support for
these observations.
GCN Circular 9248
Subject
GRB090424: BVRI/R-band detection after 15 hrs burst
Date
2009-04-25T06:52:02Z (17 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
M. Im, W. Park, Y. Jeon, I. Lee (CEOU/Seoul National Univ),
Y.-B. Jeon (KASI) and Y. Urata (NCU) on behalf of EAFON team.
We took BVRI-band images of GRB090424 (GCN 9223)
using the 1.0m telescope at Mt. Lemmon (Arizona, US)
operated by the Korea Astronomy Space Science Institute.
The whole sequence of the observation started at
2009 April 25, 04:30:19 UT, among which R-band observation
started at 04:58:32.22.
From a stacked image of 6 frames (3 min exp. each),
we cleary detect the afterglow at R=19.9 +- 0.14 mag, calibrated
against USNO-B1 stars in the vicinity. The mid-point of the
obseravation is April 25, 05:10:57 UT (14.97 hrs after
the burst).
Analysis of the BVI data is ongoing.
We thank the LOAO operator, J. Yoon for his assistance for this
observation.
GCN Circular 9247
Subject
GRB 090424 : Lulin 1m telescope optical observations
Date
2009-04-25T06:06:14Z (17 years ago)
From
Yuji Urata at Nat. Central U. <urata@astro.ncu.edu.tw>
Y. Urata(NCU), K. Y. Huang (ASIAA)
on behalf of EAFON report;
"We have observed optical afterglow of GRB090424 (Cannizzo et al., GCN
#9223, Yuan et al. GCN #9224; Xin et al. GCN #9225; Schady et
al. #9234; Gorosabel et al. GCN #9236; Urata et al. GCN #9240,
Olivares et al GCN #9245; Nissinen et al. GCN #9246) using Lulin 1m
telescope (LOT) with B, V, R, I and z'-band filters. Observations
started at 14:34:18 UT on 24 April. These LOT images show the
afterglow clearly. Based on our preliminary photometry compared with
USNO B1.0 stars, the R-band light curve between 1329 sec and 13303 sec
after the burst is well fitted by a simple power law with the decay
index 0.71."
GCN Circular 9246
Subject
GRB 090424: THO optical observations
Date
2009-04-25T05:35:50Z (17 years ago)
From
Veli-Pekka Hentunen at Taurus Hill Obs,A95 <veli-pekka.hentunen@kassiopeia.net>
Markku Nissinen (Taurus Hill Observatory) and Veli-Pekka Hentunen (Taurus
Hill Observatory) report:
We used 0.35m C14 XLT telescope with SBIG ST-8XME CCD at Taurus Hill Observatory
(Varkaus, Finland) for follow-up observations of GRB090424. The observations
were started on April 24, at 19:59 UTC (5.8 hours after the burst) and stopped
on April 24, at 23:11 UTC. Sixteen unfiltered 600 seconds images were taken.
We detected clear optical afterglow object at the position of RA 12h 38m 05s.12 and DEC
+16o 50' 15".2 with respect to POSSII F/USNO-B1.0 which is in good correlation
with enhanced Swift XRT-UVOT position. Upper limit for the observations is >20.4 mag.
Quoted upper limit has been derived using POSSII F and USNO-B1.0 field stars
as reference.
Filter Tmid(s) Exp(s) Mag (CR) USNO-B1.0
u 20:14:23 600 19.55+/-0.37
u 20:37:30 600 19.95+/-0.38
u 21:32:48 600 20.15+/-0.34
A jpeg preview of the observation showing the position of the afterglow is
available at this URL: http://cutenews.kassiopeia.net/data/upimages/grb090424_ticks.jpg
GCN Circular 9245
Subject
GRB 090424: GROND Observations of the Optical/NIR Afterglow
Date
2009-04-25T04:34:34Z (17 years ago)
From
Aybuke Kupcu Yoldas at ESO <ayoldas@eso.org>
F. Olivares (MPE Garching), A. Kupcu Yoldas (ESO), J. Greiner, A. Yoldas
(both MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 090424 (Swift trigger 350311;Cannizzo et
al., GCN #9223) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla
Observatory (Chile).
Observations started at 02:52 UT on 25 April, ~12.5 hours after the GRB
trigger, and are continuing. They were performed at an average seeing of
1.0 and at an average airmass of 1.45.
We clearly detect the optical afterglow (Cannizzo et al. GCN #9223; Yuan
et al. GCN #9224; Xin et al. GCN #9225; Schady et al. #9234; Gorosabel
et al. GCN #9236).
Preliminary photometry yields the following AB magnitudes in stacked
images of the first OB, obtained using SDSS/2MASS stars as reference:
Filter Exp[s] AB Mag MagErr
----------------------------------------
g' 4x115 20.98 0.02
r' 4x115 20.42 0.04
i' 4x115 20.01 0.04
z' 4x115 19.64 0.02
J 48x10 19.08 0.09
H 48x10 18.62 0.03
K 48x10 18.29 0.04
Given magnitudes are not corrected for the expected Galactic foreground
extinction corresponding of E_(B-V)=0.03 mag (Schlegel et al. 1998).
These magnitudes combined with the results of previous observations
(Schady et al. GCN #9234, Guidorzi et al. GCN #9238) indicate a
flattening in the afterglow light-curve.
GCN Circular 9243
Subject
GRB 090424 Gemini-South Redshift
Date
2009-04-25T03:02:24Z (17 years ago)
From
Ryan Chornock at UC Berkeley <chornock@astro.berkeley.edu>
R. Chornock, D. A. Perley, S. B. Cenko, and J. S. Bloom (UC Berkeley) report on
behalf of a larger collaboration:
We obtained optical spectra of the afterglow of GRB 090424 (Cannizzo et al., GCN
9223) using GMOS on Gemini-South. Our spectra cover the wavelength range of
4400-8600 angstroms. Our first 1200s exposure, starting at 01:51:56 April 25 UT
(11.7 hr after the trigger) reveals.a pair of absorption lines at 6077 and 6130
Angs, which we identify as the Ca II H+K doublet at z=0.544. Additionally, an
emission line is present at 5758 A, which is consistent with the [O II] 3727
doublet at the same redshift, which we therefore identify as the redshift of the
host galaxy. We note that this redshift is significantly higher than the
photo-z noted by Evans & Holland (GCN 9226).
GCN Circular 9240
Subject
GRB 090424 : TAOS optical detection
Date
2009-04-25T01:27:48Z (17 years ago)
From
Kuiyun Huang at ASIAA <ljhuang@asiaa.sinica.edu.tw>
GRB 090424 : TAOS optical detection
Y. Urata, Z.W. Zhang, C.Y. Wen, K.Y. Huang, S.Y. Wang and the TAOS
team
Three 50cm TAOS telescopes, located at Lulin observatory, Taiwan,
started to observe GRB 090424 field (Cannizzo et al.; GCN 9223) at 94s
after the trigger. The optical afterglow (Yuan et al., GCN 9224; Xin
et al. GCN 9225) was clearly detected in images taken by TAOSA (25s
exposure), TAOSB (5s exposure), and TAOSD (1s exposure). Brightness of
the afterglow is about R~13.08 at 94s post the burst. Our R-band
magnitude were calibrated with USNOB red stars.
this message can be cited
GCN Circular 9239
Subject
GRB 090424 optical observations
Date
2009-04-24T23:40:52Z (17 years ago)
From
AAVSO GRB Network at AAVSO <matthewt@aavso.org>
Arto Oksanen (Hankasalmi Obs., Hankasalmi, Finland) reports via the AAVSO
International High Energy Network the following optical observations of
GRB 090424 (Cannizzo et al., GCN #9223):
A. Oksanen reports the detection of the optical counterpart of GRB 090424
approximately 6.5 hours post-burst. Unfiltered observations were made
using a 0.4-meter RC telescope with an SBIG STL-1001E CCD. A total of
sixty, 60-second observations were made having a mid-point time of
20:45:00 UT on 2009 April 24. The afterglow was detected with a magnitude
of 19.1 +/- 0.1 measured relative to the R band magnitude of USNO-A2.0
1050-06753889 (R=16.3). Astrometry of the afterglow position yields a
position of RA: 12h 38m 05.1s, Dec: +16d 50m 15.3s, in agreement with the
UVOT coordinates given by Cannizzo et al. (GCN #9223).
A jpeg preview of the observation showing the position of the afterglow is
available at this URL:
http://murtoinen.dyndns.org:8888/ccd/grb/GRB090424/GRB090424-S001-R0XX-Clear.jpg
A detailed report of the observation is available at the following URL:
ftp://ftp.aavso.org/grb/ArtoOksanen_GRB090424_2454946.42162_.txt
A FITS image of this observation is available at the following URL:
ftp://ftp.aavso.org/grb/ArtoOksanen_GRB090424_2454946.42162_.fits
The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.
GCN Circular 9238
Subject
GRB 090424: Liverpool Telescope observations
Date
2009-04-24T23:24:58Z (17 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), D. Bersier (Liverpool JMU),
and N. Tanvir (U. Leicester) on behalf of a larger
collaboration report:
We began observing the field of GRB 090424 (Cannizzo et al.
GCN Circ. 9223) with the 2-m Liverpool Telescope at
21:29:47 UT. We clearly detect the optical afterglow
(Cannizzo et al. GCN Circ 9223; Yuan et al. GCN Circ. 9224;
Xin et al. GCN Circ. 9225; Schady et al. GCN Circ. 9234;
Gorosabel et al. GCN Circ. 9236) with r'=19.93 � 0.03
at a mid epoch of 7.55 hrs post burst from a 6x300 s coadded
exposure. Calibration was performed with respect to nearby
SDSS field stars.
GCN Circular 9237
Subject
GRB 090424: Swift-XRT refined analysis
Date
2009-04-24T23:15:47Z (17 years ago)
From
Raffaella Margutti at U. di Milano Bicocca <raffaella.margutti@brera.inaf.it>
R. Margutti (Univ. Bicocca & INAF-OAB), C. Guidorzi (Univ. Ferrara),
J. Mao (INAF-OAB) and J. K. Cannizzo (NASA/UMBC) report on behalf of
the Swift-XRT team:
We have analysed the first 2 orbits of Swift-XRT data obtained for
GRB 090424 (Cannizzo et al. GCN Circ. 9223), covering 1732 s of
Windowed Timing (WT) and 1329 s of Photon Counting (PC) mode data,
respectively, between 88 s and 8 ks after the trigger.
The UVOT-enhanced XRT position was given by Goad et al. in GCN Circ. 9232.
The light-curve can be modelled by a double broken power-law, with
a first decaying index alpha_1= 1.29 +/- 0.05 and a first break time
of about 260 s. The decay then flattens to alpha_2= 0.74 +/- 0.02.
After 1450 s the decay is best modelled by a power-law index
alpha_3= 1.15 +/- 0.05.
The very good statistics allows us to observe spectral evolution
in WT data before the first break, with the simple power law photon index
evolving from 2.6 to 2.1 . A spectrum extracted from WT mode data in the
time interval 0.4-1.4 ks can be modelled with an absorbed
power-law with a photon index Gamma= 2.13 +/- 0.05 and best-fitting
absorption column NH = (0.20 +/- 0.01) x10^22 cm^-2, in excess of the
Galactic
value of 1.9 x 10^20 cm^-2 (Kalberla et al. 2005).
The spectrum extracted from PC data in the time interval 6.1-8 ks
can be modelled with an absorbed power-law, with Gamma = 2.06 +/- 0.09
and a column density of NH = (0.27 +/- 0.03)x10^22 cm^-2.
The observed (unabsorbed) 0.3 -10 keV flux over this time interval is
4.2x10^-11 (6.7x10^-11) erg cm^-2 count^-1.
Uncertainties are given at 90% confidence.
If the light-curve continues to decay with alpha ~1.15, the count rate 24
hours after the burst is estimated to be 0.10 count s^-1, which
corresponds to an observed (unabsorbed) flux of 4.2x10^-12
(6.7x10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00350311.
This circular is an official product of the Swift-XRT team.
GCN Circular 9236
Subject
GRB 090424: Optical observations from 1.23m CAHA
Date
2009-04-24T22:59:07Z (17 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel, P. Kubanek , M. Jelinek (IAA-CSIC), A. de Ugarte
Postigo (ESO),
J. Aceituno (CAHA), report on behalf of a larger collaboration:
We have observed the field of GRB 090424 (Cannizzo et al., GCN 9223)
with
the 1.23m telescope at Calar Alto. The afterglow is clearly detected
in BVRI-bands.
On April 24.87 UT the afterglow showed a magnitude of R = 19.3 +/-
0.1, as
compared to stars from the USNO-B1.0.
Calar Alto is operated jointly by MPIA and IAA-CSIC.
Further observations are ongoing.
GCN Circular 9234
Subject
Swift/UVOT observations of GRB 090424
Date
2009-04-24T21:42:37Z (17 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
P.Schady (MSSL/UCL) and J. K. Cannizzo (NASA/UMBC) report on behalf of the
Swift/UVOT team:
The Swift/UVOT started settled observations of the burst GRB090424
(Cannizzo et al. GCN Circ. 9223) with the finding chart (fc) exposure in
white, 167s after the BAT trigger. The afterglow is detected in the all
filters at the position reported by Cannizzo et al. (GCN Circ. 9223),
placing an upper limit on the redshift of ~1.3. The combined UVOT data
indicates that the afterglow is fading with a decay index of alpha ~ 0.9.
The UVOT magnitudes our reported below:
Filter Tmid(s) Exp(s) Magnitude
white (fc) 167 147.4 15.27 +/- 0.01
u (fc) 429 245.8 16.40 +/- 0.03
white 594 19.4 16.99 +/- 0.07
v 644 19.5 16.86 +/- 0.19
b 570 19.5 17.27 +/- 0.13
u 1122 19.5 17.44 +/- 0.20
uvw1 695 19.5 16.81 +/- 0.19
uvm2 670 19.4 17.39 +/- 0.34
uvw2 793 19.4 17.51 +/- 0.27
The values quoted above are in the UVOT photometric system (Poole et al.
2008, MNRAS, 383, 627) and are not corrected for the expected Galactic
extinction corresponding to a reddening of E(B-V)=0.025 mag in the
direction of the burst (Schlegel et al. 1998).
GCN Circular 9233
Subject
GRB 090424: MASTER-Net prompt optical observations
Date
2009-04-24T21:01:23Z (17 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina,
D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov
Sternberg Astronomical Institute, Moscow State University
K.Ivanov, S.Yazev
Irkutsk State University
A. Tlatov, A.V. Parhomenko,
Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinski, I.Zalognikh, T.Kopytova
Ural State University, Kourovka
There are 6 MASTER Very Wide Field cameras located at Kislovodsk and Irkutsk
with common FOW = 6000 square degrees (http://observ.pereplet.ru/).
One of the two MASTER Very Wide Field Cameras located at Irkutsk
(D=50 mm, 2x1000 square degrees, 11 Mpx, 72" per pix in binning regime)
has observed UVOT error box (Cannizzo et al., GCN 9223) with 1s exposure
befoure, during and after GRB Time without time gap between images.
The error box is near at the center of our FOW.
Our unfiltered images are calibrated relative to Tycho stars (V).
The magnitude limit of the each emage is ~8 m at the center of FOW (some
cloudy on the sky). The limit of coadded five images ~ 9 m.
The reduction is continued.
The message may be cited.
mailto: lipunov@sai.msu.ru
GCN Circular 9232
Subject
GRB 090424: Enhanced Swift-XRT position
Date
2009-04-24T19:40:43Z (17 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 564 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 090424, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 189.52107, +16.83773 which is equivalent
to:
RA (J2000): 12h 38m 5.06s
Dec (J2000): +16d 50' 15.8"
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, arXiv:0812.3662).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 9231
Subject
GRB 090424: Swift-BAT refined analysis
Date
2009-04-24T19:20:50Z (17 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. K. Cannizzo (NASA/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD),
D. M. Palmer (LANL), A. M. Parsons (GSFC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 090424 (trigger #350311)
(Cannizzo, et al., GCN Circ. 9223). The BAT ground-calculated position is
RA, Dec = 189.531, 16.829 deg which is
RA(J2000) = 12h 38m 07.4s
Dec(J2000) = +16d 49' 45.9"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 12%.
The mask-weighted light curve shows several overlapping bright peaks
starting at about T-2sec and ending at about T+5 sec. There are 3 much
weaker, and broader, peaks at T+7, +15, and +50 sec. The emission returns
to background at around T+150 sec. T90 (15-350 keV) is 48 +- 3 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.7 to T+103.2 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 1.19 +- 0.15,
and Epeak of 108.6 +- 20.3 keV (chi squared 45.8 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 2.1 +- 0.0 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T-0.10 sec in the 15-150 keV band is
71.0 +- 2.0 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.62 +- 0.03 (chi squared 72.0 for 57 d.o.f.). All the quoted errors
are at the 90% confidence level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/350311/BA/
GCN Circular 9230
Subject
GRB 090424: Fermi GBM Observation
Date
2009-04-24T17:46:24Z (17 years ago)
From
Valerie Connaughton at MSFC <valerie@nasa.gov>
Valerie Connaughton (UAH) reports on behalf of the Fermi GBM Team:
"At 14:08:12.67 UT on 24 April 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090424 (trigger 262275130 / 090424592).
which was also detected by the Swift-BAT
(J. Cannizzo et al. 2009, GCN 9223).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 71 degrees, increasing
after trigger time.
The GBM light curve shows an intense, multi-peaked
emission period lasting around 6 sec, tailing off
into smaller peaks until about 20 sec after trigger time,
followed by a smaller peak between 45-60 sec after the trigger.
The duration (T90) between 8 and 1000 keV is about 52 sec.
The time-averaged spectrum of the peak from T0-0.3 s to T0+5.5 s is
best fit by a Band function with Epeak = 177 +/- 3 keV,
alpha = 0.90 +/- 0.02, and beta = -2.9 +/- 0.1
The event fluence (8-1000 keV) over the entire event (-0.3 s to 59 s) is
(5.2 +/- 0.1)E-05 erg/cm^2. The 0.128-sec peak photon flux measured
at 1.4 s in the 8-1000 keV band is 137 +/- 5 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 9226
Subject
GRB 090424: SDSS Galaxy at the Swift position
Date
2009-04-24T15:23:49Z (17 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans (U. Leicester) and S.T. Holland (CRESST/USRA/GSFC) report:
We note the presence of the extended source SDSS J123805.09+165014.6 in
the UVOT error circle of GRB 090424 (Cannizzo et al. GCN Circ 9223);
0.1" away from the Swift-UVOT position. This potential host galaxy has a
photo-z of 0.26. GRB 090424 was detected in the u-band by Swift/UVOT,
which is consistent with a low redshift origin of the burst.
GCN Circular 9225
Subject
GRB 090424: TNT optical observations
Date
2009-04-24T15:21:45Z (17 years ago)
From
W.K. Zheng at NAOC <zwk@bao.ac.cn>
L.P. Xin, W.K. Zheng, Y.L. Qiu, J.Y. Wei,
j. Wang, J.S. Deng, Y. Urata and J.Y. Hu
on behalf of EAFON report:
TNT quickly responsed to the GRB 090424 (Swift trigger 350311;
Cannizzo et al. GCN 9223) in automatical mode, the first
images was taken start 14:13:36, 87s after the burst.
The optical afterglow (Cannizzo et al. GCN 9223; Yuan GCN 9224)
was clearly detected in our early white and R bands images,
after preliminary reduction, we estimated the afterglow have
faded about 3.5 mag from ~100s to ~1000s after the burst.
Observation is still under going.
This message may be cited.
GCN Circular 9224
Subject
GRB 090424: ROTSE-III Confimation of Optical Counterpart
Date
2009-04-24T14:35:53Z (17 years ago)
From
Fang Yuan at ROTSE <yuanfang@umich.edu>
F. Yuan (U Mich), report on behalf of the ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded
to GRB 090424 (Swift trigger 350311;Cannizzo et al, GCN 9223). The
first image started at 14:18:41.4 UT, ~6 min after the burst. The
unfiltered images are calibrated relative to USNO A2.0. We detect a
fading source at the position consistent with the UVOT OT, at the
following magnitude:
start UT mag mlim(of image)
----------------------------------
14:18:41.4 15.5 17.2
This source is not visible in DSS (second epoch), 2MASS or the
MPChecker database.
A jpeg image is available at http://www.rotse.net/images/gsb350311_3a001-010_key.jpg
Note that the object marked 12 is the candidate in question.
Continuing observations are in progress.
GCN Circular 9223
Subject
GRB 090424: Swift detection of a burst with an optical counterpart
Date
2009-04-24T14:23:57Z (17 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. K. Cannizzo (NASA/UMBC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
P.A. Curran (MSSL-UCL), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), C. Gronwall (PSU), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), J. Mao (INAF-OAB),
R. Margutti (Univ Bicocca&OAB), F. E. Marshall (NASA/GSFC),
P. T. O'Brien (U Leicester), K. L. Page (U Leicester),
P. Romano (INAF-IASFPA), B. A. Rowlinson (U Leicester),
M. H. Siegel (PSU), M. C. Stroh (PSU), G. Tagliaferri (INAF-OAB) and
L. Vetere (PSU) report on behalf of the Swift Team:
At 14:12:09 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090424 (trigger=350311). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 189.538, +16.829 which is
RA(J2000) = 12h 38m 09s
Dec(J2000) = +16d 49' 46"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows several bright peaks
in the first 5 seconds, and then several smaller peaks at T+8, +15,
and +50 sec. Total duration of about 60 sec. The peak count rate
was ~50000 counts/sec (15-350 keV), at ~3 sec after the trigger.
The XRT began observing the field at 14:13:33.8 UT, 84.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 189.5213, +16.8364 which is equivalent to:
RA(J2000) = 12h 38m 05.11s
Dec(J2000) = +16d 50' 11.0"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 63 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 91 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 12:38:05.11 = 189.52128
DEC(J2000) = +16:50:15.1 = 16.83753
with a 90%-confidence error radius of about 0.74 arc sec. This position is 4.1
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.29 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.03.
Burst Advocate for this burst is J. K. Cannizzo (cannizzo AT milkyway.gsfc.nasa.gov).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)