GRB 180205A
GCN Circular 22430
Subject
GRB 180205A: Mondy optical observations
Date
2018-02-21T16:55:22Z (8 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Volnova (IKI), A. Pozanenko (IKI), E. Klunko
(ISTP) report on behalf of of larger GRB follow-up collaboration:
We observed the field of GRB 180205A (Evans et al., GCN 22381) with
AZT-33IK telescope of Sayan observatory (Mondy). We obtained several
images in R and B-filter on Feb. 05 - Feb. 19. The afterglow of GRB
180205A (Evans et al., GCN 22381; Zheng et al. GCN 22382; Bolmer et al.
GCN 22383;Tanvir et al. GCN 22384; Volnova et al. GCN 22387; Falcon et
al. GCN 22380; Xin et al. GCN 22392; Zhu et al. GCN 22395; Emery et al.
GCN 22396; Im et al., GCN 22397; Oksanen et al. 22401; Mazaeva et al.,
GCN 22403; Volnova et al., GCN 22411; Cunningham et al., GCN 22414) is
detected in stacked images. Preliminary photometry is following.
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2018-02-05 15:21:12 0.49438 R 30*120 19.32 0.04 21.9
2018-02-05 16:23:51 0.53094 B 20*120 20.70 0.17 21.3
2018-02-05 20:03:02 0.69011 R 60*60 19.60 0.08 21.7
2018-02-06 16:07:42 1.50850 R 30*120 20.25 0.07 22.0
2018-02-14 15:48:28 9.50557 R 45*120 22.46 0.13 23.9
2018-02-18 13:23:22 13.40481 R 45*120 n/d n/d 23.0
2018-02-19 14:37:56 14.45658 R 45*120 23.6 0.3 23.6
The photometry is based on nearby SDSS DR9 stars
SDSS_id R_Lupton
J082719.98+113324.0 16.206 0.013
J082717.26+113400.0 16.092 0.013
J082715.06+113230.6 15.553 0.013
GCN Circular 22414
Subject
GRB 180205A: SEDM Observations
Date
2018-02-13T15:30:27Z (8 years ago)
From
Virginia Cunningham at U of MD <vcunning@astro.umd.edu>
V. Cunningham (U of Maryland), J. D. Neill (Caltech), S. B. Cenko
(NASA GSFC), and R. Walters (Caltech) report on behalf of the
SEDM team:
We observed the optical counterpart to GRB 180205A (Evans et al.,
GCN 22381) with the Spectral Energy Distribution Machine (SEDM)
on the 60 inch telescope at Palomar Observatory. The SEDM is a low
resolution (R ~ 100) integral field unit spectrometer with a multi-band
(ugri) ���rainbow��� camera imager (see Blagorodnova et al., 2017,
astro-ph/1710.02917).
The SEDM began observing the optical counterpart at 04:44 UTC
(18 minutes after the burst trigger time). We performed 2 x 1350 s
exposures over the wavelength range 3800-10600 A. We see no strong
evidence for emission or absorption features at the quoted redshift of
z=1.409 (Tanvir et al., GCN 22384). The continuum emission is well-fit
by a power law spectrum with index alpha = 0.77 (f_nu ~ nu^-alpha).
[GCN OPS NOTE(07sep19): Per author's request, in the last sentence
the "alpha = 0.67" was changed to "alpha = 0.77".]
GCN Circular 22411
Subject
GRB 180205A: BAO optical observations
Date
2018-02-11T10:53:10Z (8 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), A. Novichonok (KIAM), A. Pozanenko (IKI), S. Kotov (SAO
RAS), T. Movsesyan (BAO), E. Mazaeva (IKI) report on behalf of of
larger GRB follow-up collaboration:
We observed the field of GRB 180205A (Evans et al., GCN 22381) with
Schmidt-1m telescope of Byurakan Astrophysical Observatory (BAO). We took
several images in r (Sloan)-filter starting on Feb. 08 (UT) 12:54:29. The
afterglow of GRB 180205A (Evans et al., GCN 22381; Zheng et al. GCN 22382;
Bolmer et al. GCN 22383;Tanvir et al. GCN 22384; Volnova et al. GCN 22387;
Falcon et al. GCN 22380; Xin et al. GCN 22392; Zhu et al. GCN 22395; Emery
et al. GCN 22396; Im et al., GCN 22397; Oksanen et al. 22401; Mazaeva et
al., GCN 22403) is clearly detected in a stacked image. Preliminary
photometry is following.
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2018-02-08 18:00:00 3.59550 r 12*300 21.3 0.2 21.9
The photometry is based on several nearby SDSS DR9 stars
SDSS_id r
J082719.98+113324.0 16.357 0.005
J082717.26+113400.0 16.292 0.005
J082715.06+113230.6 15.744 0.004
GCN Circular 22404
Subject
GRB180205A: Optical observations with DOAO 1m telescope
Date
2018-02-08T13:46:01Z (8 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Changsu Choi, Myungshin Im (CEOU/SNU), Tae-Woo Kim, Wonseok Kang (KYSC), on
behalf of a larger collaboration.
We observed the field of GRB 180205A (Evans et al., GCN 22381) with the 1m
telescope of Deokheung Optical Astronomy Observatory (DOAO) in Korea,
starting from 2018/02/05 11:22:11 for three consecutive nights.
We obtained B, V, R-band images and clearly detected the afterglow in a
series of 300s exposure images. The afterglow in R band The afterglow is
dimming at a rate of about 0.75 mag per day fon average rom 02/05 to 02/07
(Evans et al., GCN 22381; Zheng et al. GCN 22382; Bolmer et al. GCN 22383;
Tanvir et al. GCN 22384; Volnova et al. GCN 22387; Falcon et al. GCN 22380;
Xin et al. GCN 22392; Zhu et al. GCN 22395; Emery et al. GCN 22396; Im et
al., GCN 22397; Oksanen et al. 22401; Mazaeva et al., GCN 22403).
Date UT mid Filter Exp. Mag(Vega) Err
2018-02-05 11:14:41 R 300s 19.47 0.12
2018-02-05 11:56:58 R 300s 19.48 0.08
2018-02-06 12:04:55 R 1200s 20.38 0.05
2018-02-06 14:07:30 R 1200s 20.29 0.04
2018-02-07 12:20:31 R 1200s 20.88 0.06
2018-02-07 13:57:28 R 1200s 21.14 0.07
The photometric calibration is based on the APASS stars within 6' radius
from GRB. The observation is continuing.
GCN Circular 22403
Subject
GRB 180205A: AbAO optical observations
Date
2018-02-08T07:52:59Z (8 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Pozanenko (IKI), A. Volnova (IKI), R. Inasaridze
(AbAO), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Inasaridze
(AbAO), I. Molotov (KIAM), report on behalf of larger GRB follow-up
collaboration:
We observed the field of GRB 180205A (Evans et al., GCN 22381) with
AS-32 (0.7m) telescope of Abastumani Observatory starting on Feb., 06
(UT) 23:53:51. We obtained several unfiltered images starting on Feb.
05 (UT) 12:54:29. The afterglow of GRB 180205A (Evans et al., GCN
22381; Zheng et al. GCN 22382; Bolmer et al. GCN 22383; Tanvir et al.
GCN 22384; Volnova et al. GCN 22387; Falcon et al. GCN 22380; Xin et al.
22392; Zhu et al. 22395; Emery et al. 22396; Im et al., GCN 22397) is
clearly detected in a stacked image. Preliminary photometry is following.
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2018-02-06 17:09:23 1.54515 CR 24*60 20.32 0.10 21.2
The photometry is based on several nearby SDSS DR9 stars
SDSS_id R_Lupton
J082719.98+113324.0 16.206 0.013
J082717.26+113400.0 16.092 0.013
J082715.06+113230.6 15.553 0.013
GCN Circular 22401
Subject
GRB 180205A optical observations
Date
2018-02-07T10:52:14Z (8 years ago)
From
Arto Oksanen at Nyrola Obs., Finland <oksanen@nyrola.jklsirius.fi>
Arto Oksanen (Hankasalmi Obs., Hankasalmi, Finland) and D. Malesani (DARK/NBI)
report the following observations of GRB 180205A (Evans et al., GCN 22381):
A. Oksanen observed the location of GRB 180205A using the Hankasalmi
Observatory 0.4-m Richey-Chretien telescope with an SBIG STL-1001E
camera. Forty 60-second frames were obtained with clear filter
between 18:19 UT and 19:41 UT on 2018 February 5.
The afterglow is detected in co-added image.
Photometry of co-added image yields the following:
t-t0(d) m(CR) err(CR)
0.605 19.43 0.06
Photometry was performed using comparison stars from the Pan-STARRS survey
(Chambers et al. 2016; arXiv:1612.05560), after adopting the conversion
formulae by Lupton (2005).
GCN Circular 22398
Subject
GRB 180205A: confirmation of Swift-BAT trigger time.
Date
2018-02-06T16:04:12Z (8 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester) and D.M. Palmer (LANL) report on behalf of the
Swift team:
Due to a telemetry gap, the trigger time of GRB 180205A was not reported
in the early GCN Circulars.
The BAT trigger time was 04:25:29.3 UT (on 2018 Feb 5). We apologise for
any inconvenience caused by the omission.
This circular is an official product of the Swift team.
[GCN OPS NOTE(06feb18): Per author's request, "UT" was added to the
time listed in the second sentence.]
GCN Circular 22397
Subject
GRB 180205A: Optical observations
Date
2018-02-06T14:45:44Z (8 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Myungshin Im, Changsu Choi, Gregory S. Paek, Sung A O, Sophia Kim
(CEOU/SNU), Yuji Urata (NCU), H.-I. Sung (KASI) on behalf of a larger
collaboration
We observed the afterglow of GRB 180205A (Evans et al., GCN 22381; Zheng et
al. GCN 22382; Bolmer et al. GCN 22383; Tanvir et al. GCN 22384; Volnova et
al. GCN 22387; Falcon et al. GCN 22380; Xin et al. 22392; Zhu et al. 22395;
Emery et al. 22396) with the 1-m telescope at the Mt. Lemmon Optical
Astronomy Observatory (LOAO) and the 0.8m and 0.25 telescopes at the
McDonald Observatory. The observation started at about 1 hour after the
initial alert, using B, V, R, I, z, and Y filters. The observation
continued throughout the night.
We clearly identify the optical afterglow in these bands, and
���a ���
preliminary photometry in R-band shows R ~ 18 mag at 1.3 hours post-burst.
Further observations and analysis are being carried out
���, including telescopes in Korea���
. Additional
���results ���
will be reported
��� as they become available���
.
GCN Circular 22396
Subject
GRB 180205A: Swift/UVOT Detection
Date
2018-02-06T12:58:32Z (8 years ago)
From
Sam Emery at MSSL-UCL <samuel.emery.15@ucl.ac.uk>
S.W.K. Emery (UCL-MSSL) and P. A. Evans (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180205A
182 s after the BAT trigger (Evans et al., GCN Circ. 22381).
A fading source consistent with the XRT position
(Page et al., GCN Circ. 22394),
also detected by (Zheng et al. GCN 22382;
Bolmer et al. GCN 22383; Tanvir et al. GCN 22384;
Volnova et al. GCN 22387; Falcon et al. GCN 22390; Xin et al. 22392;
Zhu et al. GCN 22395)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 08:27:16.74 = 126.81975 (deg.)
Dec (J2000) = +11:32:30.9 = 11.54191 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373)
for the first finding chart (FC) exposure and the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 182 331 147 15.75 +/- 0.02
white 540 732 36 16.33 +/- 0.02
v 158 612 52 16.11 +/- 0.09
b 515 710 39 16.65 +/- 0.07
u 490 686 39 16.82 +/- 0.07
uvw1 466 661 39 16.04 +/- 0.10
uvm2 441 636 39 16.32 +/- 0.15
uvw2 391 585 39 17.06 +/- 0.17
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 22395
Subject
GRB 180205A: Nanshan-1m optical observations
Date
2018-02-06T12:02:12Z (8 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu, H.X. Feng, D. Xu (NAOC), B.Y. Yu (HNU), J.H. Liu, X. Zhang,
H.B. Niu, S.G. Ma, J.Z. Liu, A. Esamdin, L. Ma, Y. Zhang (XAO) report on
behalf of a larger collaboration:
We observed the field of GRB 180205A (Evens et al., GCN 22381) using the
1m telescope located at Nanshan, Xinjiang, China, and 10x60s R-band
frames, starting at 16:31:07 UT on 2018-02-05.
The optical afterglow (e.g., Evens et al., GCN 22381; Zheng et al., GCN
22382) is clearly detected in our stacked image.
Preliminary photometry results are as follows:
Tmid-T0 Exposure Filter Mag MagErr
(hr) (s)
12.15 10x60 R 19.67 0.10
Photometry is calibrated with nearby SDSS stars, and errors are only
statistical values.
GCN Circular 22394
Subject
GRB 180205A: Swift-XRT refined Analysis
Date
2018-02-06T04:46:03Z (8 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo
(INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Tohuvavohu
(PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU) and P.A. Evans report on
behalf of the Swift-XRT team:
We have analysed 5.0 ks of XRT data for GRB 180205A (Evans et al. GCN
Circ. 22381), from 180 s to 33.8 ks after the BAT trigger. The data
comprise 85 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. Using 3849 s of PC mode data and 7 UVOT images, we
find an enhanced XRT position (using the XRT-UVOT alignment and
matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
126.81966, +11.54210 which is equivalent to:
RA (J2000): 08h 27m 16.72s
Dec(J2000): +11d 32' 31.6"
with an uncertainty of 1.5 arcsec (radius, 90% confidence).
The light curve can be modelled with an initial power-law decay with an
index of alpha=4.8 (+0.6, -0.5), followed by a break at T+279 s to an
alpha of 1.00 (+/-0.04).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.72 (+0.18, -0.17). The
best-fitting absorption column is 8.7 (+2.8, -2.5) x 10^21 cm^-2, at a
redshift of 1.409, in addition to the Galactic value of 3.4 x 10^20
cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index
of 1.89 (+0.15, -0.14) and a best-fitting absorption column of 3.1
(+3.0, -2.6) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10
keV flux conversion factor deduced from this spectrum is 3.5 x 10^-11
(4.0 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Galactic foreground: 3.4 x 10^20 cm^-2
Intrinsic column: 3.1 (+3.0, -2.6) x 10^21 cm^-2 at z=1.409
Photon index: 1.89 (+0.15, -0.14)
If the light curve continues to decay with a power-law decay index of
1.00, the count rate at T+24 hours will be 0.013 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.5 x
10^-13 (5.2 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00808625.
This circular is an official product of the Swift-XRT team.
GCN Circular 22393
Subject
GRB 180205A: Swift-BAT refined analysis
Date
2018-02-06T02:57:19Z (8 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), P. A. Evans (U Leicester),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+700 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180205A (trigger #808625)
(Evans et al., GCN Circ. 22381). The BAT ground-calculated position is
RA, Dec = 126.819, 11.536 deg which is
RA(J2000) = 08h 27m 16.5s
Dec(J2000) = +11d 32' 11.1"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 50%.
The mask-weighted light curve shows a multi-peaked structure that starts
at ~T-7 s and ends at ~T+11 s. The two major peaks occur at ~T-5 s
and ~T0 s, respectively. T90 (15-350 keV) is 15.5 +- 3.1 sec (estimated
error including systematics).
The time-averaged spectrum from T-7.04 to T+10.87 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.04 +- 0.13. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.20 sec in the 15-150 keV band
is 3.4 +- 0.3 ph/cm2/sec. 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/808625/BA/
GCN Circular 22392
Subject
GRB 180205A: Xinglong TNT optical observation
Date
2018-02-06T02:43:28Z (8 years ago)
From
L.P. Xin at NAOC <xlp@nao.cas.cn>
L. P. Xin, F. Q. Pi, J. Y. Wei, Y. L. Qiu, J. S. Deng,
J. Wang, X. H. Han, X. M. Meng, C. Wu, D. TURPIN, H. L. Li report:
We began to observe GRB 180205A (Evens et al., GCN 22381)
with Xinglong 0.8-m TNT telescope, China, at 2018-02-05, 16:11:42(UT),
about 12.6 hours the burst.
We obtained several R-band images with an exposure time of 300 sec for each frame.
The optical afterglow (Evens et al., GCN 22381; Zheng et al., GCN 22382;
Bolmer et al., GCN 22383, 22391; Tanvir et al., GCN 22384; Volnova et al., GCN 22387,
Wiersema et al., GCN 22388; Falcon et al., 22390 ) is clearly detected in our stacked image with 5*300 sec.
The brightness is estimated to be about R~19.97 mag calibrated
by USNO B1.0 R2 mag at about 12.7 hours after the burst,
We acknowledge the excellent support from Xinglong staff Miao Zhang.
GCN Circular 22391
Subject
GRB 180205A: Further GROND Observations reveal Afterglow is still bright
Date
2018-02-06T02:28:56Z (8 years ago)
From
Alexander Kann at IAA-CSIC <kann@iaa.es>
J. Bolmer (ESO/MPE) and D.A. Kann (HETH/IAA-CSIC) report:
We once more observed the field of GRB 180205A (Swift trigger 808625;
P.A. Evans et al., GCN 22381) simultaneously in g'r'i'z'JHK with GROND
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope
at ESO La Silla Observatory (Chile).
Observations started at 01:28 UT on February 06, 2018, 0.8765 days after
the GRB trigger. They were performed at an average seeing of 1".1 and at
an average airmass of 1.68.
Based on total exposures of 1320 seconds in g'r'i'z' and 1200 seconds in
JHK at a midtime of 01:40 UT, 0.8854 days after the burst, we measure
the following preliminary magnitudes (AB magnitude system):
g' = 20.29 +/- 0.03 mag,
r' = 20.03 +/- 0.03 mag,
i' = 19.81 +/- 0.03 mag,
z' = 19.66 +/- 0.03 mag,
J = 19.47 +/- 0.12 mag,
H = 19.16 +/- 0.19 mag, and
K > 17.6 mag.
These magnitudes are significantly brighter than the extrapolation of
our GROND data from the first night (Bolmer & Kann, GCN 22383). We point
out that the Nickel/KAIT light curve (E. Falcon, GCN 22390) shows a
plateau phase setting in beyond 10ks, at a time we were not able to
observe with GROND anymore. This plateau would explain why the afterglow
remains bright.
Magnitudes and are calibrated against SDSS and 2MASS field stars and are
not corrected for the Galactic foreground extinction corresponding to a
reddening of E_(B-V)= 0.03 mag in the direction of the burst (Schlegel
et al. 1998).
Further observations are encouraged.
We thank Markus Rabus for the excellent support from La Silla.
GCN Circular 22390
Subject
GRB 180205A: Nickel telescope optical observations
Date
2018-02-06T00:10:25Z (8 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
Edward Falcon, Sameen Yunus, WeiKang Zheng and Alex Filippenko (UC Berkeley)
report on behalf of the KAIT GRB team:
We observed the field of GRB 180205A (Evans et al., GCN 22381) with
the 1-m Nickel telescope located at Lick observatory, California.
Observations started about 1.32 hours after the burst and lasted for
~1.4 hours. We detected the optical afterglow (Evans et al. GCN 22381;
Zheng et al. GCN 22382; Bolmer et al. GCN 22383; Tanvir et al. GCN 22384;
Volnova et al. GCN 22387) in all the images taken with B,V,R and I filters.
A preliminary light curve is posted at the following link along with KAIT
observations (Zheng et al. GCN 22382):
http://astro.berkeley.edu/~zwk/grb/GRB180205A/GRB180205A_nickel_kait.png
GCN Circular 22388
Subject
GRB 180205A: VLT polarimetry
Date
2018-02-05T19:20:24Z (8 years ago)
From
Klaas Wiersema at U of Warwick <K.Wiersema@warwick.ac.uk>
K. Wiersema (Warwick) & S. Covino (INAF / OAB) report on behalf of the
Stargate consortium:
We observed the afterglow of GRB 180205A (Evans et al. GCN 22381;
Zheng et al. GCN 22382; Bolmer et al. GCN 22383, Tanvir et al. GCN 22384)
with the ESO Very Large Telescope equipped with FORS2. We obtained
a set of imaging polarimetry observations in R band, starting at 07:07 UT
(approximately 2.67 hours after burst). Using archival calibration data, we
find a low level of polarisation, P ~ 0.9%, similar to the majority of
late-time GRB afterglow measurements (Covino & Gotz 2016, A&AT 29, 205).
We acknowledge excellent support from the ESO staff.
GCN Circular 22387
Subject
GRB 180205A: Mondy optical observations
Date
2018-02-05T19:19:37Z (8 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), E. Mazaeva
(IKI) report on behalf of of larger GRB follow-up collaboration:
We observed the field of GRB 180205A (Evans et al., GCN 22381) with
AZT-33IK telescope of Sayan observatory (Mondy). We took several images
in R-filter starting on Feb. 05 (UT) 12:54:29. The afterglow of GRB
180205A (Evans et al., GCN 22381; Zheng et al., GCN 22382; Bolmer et
al., GCN 22383) is clearly detected in a stacked image. Preliminary
photometry is following.
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2018-02-05 12:54:29 0.372* R 30*120 19.47 0.07 21.8
* The time after XRT observation start at (UT) 04:28:23.69.
The photometry is based on several nearby SDSS DR9 stars
SDSS_id R_Lupton
J082719.98+113324.0 16.206 0.013
J082717.26+113400.0 16.092 0.013
J082715.06+113230.6 15.553 0.013
GCN Circular 22386
Subject
GRB 180205A: Fermi GBM observation
Date
2018-02-05T19:12:58Z (8 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:
"At 04:25:25.39 UT on 05 February 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180205A (trigger 539497530 / 180205184),
which was also detected by the Swift/BAT (Evans et al. 2008, GCN 22381)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 94
degrees.
The GBM light curve shows several pulses with a duration (T90) of about 15 s
(50-300 keV).
The GBM detectors were turned off for SAA entry about 70 seconds after the
trigger. The time-averaged spectrum from T0-2.048 s to T0+9.216 s is
well fit by a power law function with an exponential high-energy cutoff.
The power law index is -1.38 +/- 0.15 and the cutoff energy,
parameterized as Epeak, is 85.0 +/- 14.4 keV
The event fluence (10-1000 keV) in this time interval is
(1.5 +/- 1.4)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+3.71204 s in the 10-1000 keV band
is 4.7 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 22384
Subject
GRB 180205A: VLT/X-shooter redshift
Date
2018-02-05T10:09:25Z (8 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir (U. Leicester), K. E. Heintz (U. Iceland, DARK/NBI),
J. Selsing (DARK/NBI), J. Japelj (API, U. Amsterdam),
J. Bolmer (ESO/MPE), D. A. Kann (HETH/IAA-CSIC), D. Xu (NAOC),
A. de Ugarte Postigo (HETH/IAA-CSIC and DARK/NBI),
D. Malesani (DARK/NBI), J. P. U. Fynbo (NBI), G. Pugliese (API, U. Amsterdam)
report on behalf of the STARGATE Consortium:
We observed the bright optical counterpart of the Swift
GRB 180205A (Evans et al. GCN 22381; Zheng et al. GCN 22382;
Bolmer et al. GCN 22383) with the ESO Very Large Telescope UT 2 (Kueyen)
equipped with the X-shooter spectrograph, covering the wavelength
range 3500-24000 AA. Observations started on February 05.25 UT
(approx 1.5 hr after the GRB) and consisted of 4 exposures of
600 s each.
The spectrum exhibits many absorption features including
C II, Si II, Si II*, Al II, Fe II, Mg II, Mg I at a common redshift of
z=1.409. We conclude this is the redshift of the GRB.
We acknowledge the expert support from the ESO observing
staff, in particular Jesus Corral-Santana and Cedric Ledoux.
GCN Circular 22383
Subject
GRB 180205A: GROND detection of the NIR/optical afterglow
Date
2018-02-05T06:02:56Z (8 years ago)
From
Jan Bolmer at MPE/Garching <jan@bolmer.de>
J. Bolmer (ESO/MPE) and D.A. Kann (HETH/IAA-CSIC) report:
We observed the field of GRB 180205A (Swift trigger 808625; P.A. Evans et al.,
GCN 22381) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla
Observatory (Chile).
Observations started at 04:38 UT on February 05, 2018, 13 minutes after
the GRB trigger. They were performed at an average seeing of 1".1 and at
an average airmass of 1.33.
We clearly detect the NIR/optical transient of GRB 181205A reported
also by Zheng et al., GCN 22382.
Based on total exposures of 200 seconds in g���r'i'z��� and 180 seconds in JHK
at a midtime of 04:43 UT, 17 minutes after the burst, we measure
the following preliminary magnitudes (AB magnitude
system):
g' = 16.83 +/- 0.01 mag,
r' = 16.68 +/- 0.01 mag,
i' = 16.56 +/- 0.01 mag,
z' = 16.38 +/- 0.01 mag,
J = 16.22 +/- 0.02 mag,
H = 16.05 +/- 0.02 mag, and
K = 16.08 +/- 0.14 mag.
Magnitudes and are calibrated against PanSTARRS and 2MASS
field stars and are not corrected for the Galactic foreground extinction
corresponding to a reddening of E_(B-V)= 0.03 mag in the direction of the
burst (Schlegel et al. 1998).
Observations are continuing.
We thank Markus Rabus for the excellent support from La Silla.
GCN Circular 22382
Subject
GRB 180205A: KAIT optical afterglow confirmation
Date
2018-02-05T05:15:27Z (8 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
WeiKang Zheng and Alex Filippenko (UC Berkeley) report on behalf
of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 180205A (Evans, et al.,GCN
22381), starting at 04:31:40 UT immediately after receiving the
trigger. Observations were performed with an automatic sequence
in the clear (roughly R), V, and I filters, and the exposure time
was 20 s per imag. We detect the bright optical afterglow reported
by UVOT (Evans, et al.,GCN 22381). It faded from clear ~15.6 mag
from our first clear band image to ~16.8 mag 22.5 minutes later,
we therefore confirm it to be the optical afterglow of GRB 180205A.
GCN Circular 22381
Subject
GRB 180205A: Swift detection of a burst with a bright optical counterpart
Date
2018-02-05T04:45:57Z (8 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
P. A. Evans (U Leicester), J. A. Kennea (PSU),
K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of
the Neil Gehrels Swift Observatory Team:
BAT has detected GRB 180205A (trigger #808625), leading to a slew
and follow-up observations by Swift. However, due to missing
telemetry packets, no further BAT information is available at
this time.
The XRT began observing the field at 04:28:23.6 UT. XRT found
a bright, uncatalogued X-ray source
located at RA, Dec 126.8206, 11.5419 which is equivalent to:
RA(J2000) = +08h 27m 16.94s
Dec(J2000) = +11d 32' 30.8"
with an uncertainty of 5.6 arcseconds (radius, 90% containment). No
event data are yet available to determine the column density using
X-ray spectroscopy.
The initial flux in the 2.5 s image was 9.50e-10 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
at 04:28:30.79 UT. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 08:27:16.73 = 126.81970
DEC(J2000) = +11:32:30.7 = 11.54185
with a 90%-confidence error radius of about 0.61 arc sec. This position is 3.2
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.65 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 P. A. Evans (pae9 AT star.le.ac.uk).
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.)