Gamma-ray Burst 170214A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 14 Feb 17 15:34:32 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      47
TRIGGER_NUM:     508779271
GRB_RA:          256.067d {+17h 04m 16s} (J2000),
                 256.295d {+17h 05m 11s} (current),
                 255.401d {+17h 01m 36s} (1950)
GRB_DEC:          -5.350d {-05d 20' 59"} (J2000),
                  -5.373d {-05d 22' 21"} (current),
                  -5.281d {-05d 16' 52"} (1950)
GRB_ERROR:       16.33 [deg radius, statistical plus systematic]
GRB_INTEN:       128 [cnts/sec]
DATA_SIGNIF:     6.00 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        17798 TJD;    45 DOY;   17/02/14
GRB_TIME:        56066.92 SOD {15:34:26.92} UT
GRB_PHI:          60.00 [deg]
GRB_THETA:        30.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      0.51
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      93%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       1,1,0, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       328.38d {+21h 53m 32s}  -12.80d {-12d 48' 13"}
SUN_DIST:         71.38 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
MOON_POSTN:      190.40d {+12h 41m 36s}   -0.99d {-00d 59' 16"}
MOON_DIST:        65.91 [deg]
MOON_ILLUM:      86 [%]
GAL_COORDS:       15.00, 20.91 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      255.45, 17.39 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170214649/quicklook/glg_lc_medres34_bn170214649.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 232.75,19.07 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 14 Feb 17 15:34:38 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      58
TRIGGER_NUM:     508779271
GRB_RA:          253.200d {+16h 52m 48s} (J2000),
                 253.435d {+16h 53m 44s} (current),
                 252.516d {+16h 50m 04s} (1950)
GRB_DEC:          -9.400d {-09d 24' 00"} (J2000),
                  -9.427d {-09d 25' 38"} (current),
                  -9.318d {-09d 19' 04"} (1950)
GRB_ERROR:       7.50 [deg radius, statistical plus systematic]
GRB_INTEN:       204 [cnts/sec]
DATA_SIGNIF:     20.60 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        17798 TJD;    45 DOY;   17/02/14
GRB_TIME:        56066.92 SOD {15:34:26.92} UT
GRB_PHI:          60.00 [deg]
GRB_THETA:        25.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.55
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      94%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       1,1,0, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       328.38d {+21h 53m 32s}  -12.80d {-12d 48' 13"}
SUN_DIST:         73.37 [deg]   Sun_angle= 5.0 [hr] (West of Sun)
MOON_POSTN:      190.40d {+12h 41m 36s}   -0.99d {-00d 59' 17"}
MOON_DIST:        63.25 [deg]
MOON_ILLUM:      86 [%]
GAL_COORDS:        9.70, 21.10 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      252.98, 13.05 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170214649/quicklook/glg_lc_medres34_bn170214649.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 232.75,19.07 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 14 Feb 17 15:34:46 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      69
TRIGGER_NUM:     508779271
GRB_RA:          249.200d {+16h 36m 48s} (J2000),
                 249.430d {+16h 37m 43s} (current),
                 248.529d {+16h 34m 07s} (1950)
GRB_DEC:          -6.850d {-06d 50' 59"} (J2000),
                  -6.884d {-06d 53' 00"} (current),
                  -6.750d {-06d 44' 58"} (1950)
GRB_ERROR:       5.18 [deg radius, statistical plus systematic]
GRB_INTEN:       485 [cnts/sec]
DATA_SIGNIF:     49.30 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        17798 TJD;    45 DOY;   17/02/14
GRB_TIME:        56066.92 SOD {15:34:26.92} UT
GRB_PHI:          72.00 [deg]
GRB_THETA:        25.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.62
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   3%  Generic Transient
DETECTORS:       1,1,0, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       328.38d {+21h 53m 32s}  -12.80d {-12d 48' 13"}
SUN_DIST:         77.76 [deg]   Sun_angle= 5.3 [hr] (West of Sun)
MOON_POSTN:      190.40d {+12h 41m 36s}   -0.99d {-00d 59' 18"}
MOON_DIST:        59.14 [deg]
MOON_ILLUM:      86 [%]
GAL_COORDS:        9.56, 25.81 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      248.59, 15.06 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170214649/quicklook/glg_lc_medres34_bn170214649.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 232.75,19.07 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 14 Feb 17 15:34:52 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      74
TRIGGER_NUM:     508779271
GRB_RA:          249.417d {+16h 37m 40s} (J2000),
                 249.647d {+16h 38m 35s} (current),
                 248.745d {+16h 34m 59s} (1950)
GRB_DEC:          -6.900d {-06d 54' 00"} (J2000),
                  -6.933d {-06d 56' 00"} (current),
                  -6.801d {-06d 48' 01"} (1950)
GRB_ERROR:       4.67 [deg radius, statistical plus systematic]
GRB_INTEN:       697 [cnts/sec]
DATA_SIGNIF:     70.70 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        17798 TJD;    45 DOY;   17/02/14
GRB_TIME:        56066.92 SOD {15:34:26.92} UT
GRB_PHI:          72.00 [deg]
GRB_THETA:        25.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.57
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       1,1,0, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       328.38d {+21h 53m 32s}  -12.80d {-12d 48' 13"}
SUN_DIST:         77.53 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      190.40d {+12h 41m 37s}   -0.99d {-00d 59' 19"}
MOON_DIST:        59.36 [deg]
MOON_ILLUM:      86 [%]
GAL_COORDS:        9.65, 25.60 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      248.81, 15.04 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170214649/quicklook/glg_lc_medres34_bn170214649.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 232.75,19.07 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 14 Feb 17 15:34:41 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     508779271
GRB_RA:          260.300d {+17h 21m 12s} (J2000),
                 260.545d {+17h 22m 11s} (current),
                 259.586d {+17h 18m 21s} (1950)
GRB_DEC:         -15.120d {-15d 07' 11"} (J2000),
                 -15.136d {-15d 08' 08"} (current),
                 -15.071d {-15d 04' 16"} (1950)
GRB_ERROR:       6.46 [deg radius, statistical only]
DATA_SIGNIF:     12.90 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        17798 TJD;    45 DOY;   17/02/14
GRB_TIME:        56066.92 SOD {15:34:26.92} UT
GRB_PHI:          39.00 [deg]
GRB_THETA:        26.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       328.38d {+21h 53m 32s}  -12.80d {-12d 48' 13"}
SUN_DIST:         65.61 [deg]   Sun_angle= 4.5 [hr] (West of Sun)
MOON_POSTN:      190.40d {+12h 41m 36s}   -0.99d {-00d 59' 17"}
MOON_DIST:        70.59 [deg]
MOON_ILLUM:      86 [%]
GAL_COORDS:        8.71, 12.16 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      260.55,  8.00 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170214649/quicklook/glg_lc_medres34_bn170214649.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_508779271.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 14 Feb 17 15:35:38 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      131
TRIGGER_NUM:     508779271
GRB_RA:          250.850d {+16h 43m 24s} (J2000),
                 251.080d {+16h 44m 19s} (current),
                 250.178d {+16h 40m 43s} (1950)
GRB_DEC:          -6.917d {-06d 55' 00"} (J2000),
                  -6.948d {-06d 56' 51"} (current),
                  -6.824d {-06d 49' 25"} (1950)
GRB_ERROR:       4.87 [deg radius, statistical plus systematic]
GRB_INTEN:       1105 [cnts/sec]
DATA_SIGNIF:     111.70 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        17798 TJD;    45 DOY;   17/02/14
GRB_TIME:        56066.92 SOD {15:34:26.92} UT
GRB_PHI:          72.00 [deg]
GRB_THETA:        25.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.52
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      94%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       1,1,0, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       328.38d {+21h 53m 32s}  -12.80d {-12d 48' 12"}
SUN_DIST:         76.14 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      190.41d {+12h 41m 38s}   -0.99d {-00d 59' 27"}
MOON_DIST:        60.78 [deg]
MOON_ILLUM:      86 [%]
GAL_COORDS:       10.52, 24.42 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      250.28, 15.22 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170214649/quicklook/glg_lc_medres34_bn170214649.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 232.75,19.07 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN Circular #20675
B. Mailyan and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 15:34:26.92 UT on 14 February 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170214A (trigger 508779271 / 170214649).
The on-ground calculated location, using the GBM trigger data, is RA = 255.61, DEC = -5.78 (J2000 degrees), equivalent to J2000 17h 02m, -05d 46', with an uncertainty of 1 degree (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).
The trigger resulted in an Autonomous Repoint Request (ARR) by the GBM Flight Software owing to the high peak flux of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight location. The initial angle from the Fermi LAT boresight to the GBM ground location is 29 degrees.
The GBM light curve shows multiple overlaping peaks with a duration (T90) of about 123 s (50-300 keV). The time-averaged spectrum from T0+12.8 s to T0+136.7 s is best fit by a Band function with Epeak = 408.50 +/- 9.09 keV, alpha = -0.84 +/- 0.01, and beta = -2.34 +/- 0.05.
The event fluence (10-1000 keV) in this time interval is (1.8 +/- 0.002)E-4 erg/cm^2. The 1-sec peak photon flux measured starting from T0+61.7 s in the 10-1000 keV band is 17.8 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."

GCN NOTICE

 
TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 14 Feb 17 23:48:16 UT
NOTICE_TYPE:     Fermi-LAT Offline Position
TRIGGER_NUM:     508779271
GRB_RA:          256.330d {+17h 05m 19s} (J2000),
                 256.552d {+17h 06m 13s} (current),
                 255.681d {+17h 02m 43s} (1950)
GRB_DEC:          -1.880d {-01d 52' 47"} (J2000),
                  -1.902d {-01d 54' 07"} (current),
                  -1.813d {-01d 48' 44"} (1950)
GRB_ERROR:       4.80 [arcmin radius, 90% containment, statistical only]
GRB_DATE:        17798 TJD;    45 DOY;   17/02/14
GRB_TIME:        56066.92 SOD {15:34:26.92} UT
TRIGGER_ID:      0x20000000    
MISC:            0x40000000    
SUN_POSTN:       328.72d {+21h 54m 52s}  -12.69d {-12d 41' 10"}
SUN_DIST:         72.18 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
MOON_POSTN:      194.45d {+12h 57m 48s}   -2.37d {-02d 22' 09"}
MOON_DIST:        62.06 [deg]  
MOON_ILLUM:      84 [%]
GAL_COORDS:       18.34, 22.48 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      255.36, 20.87 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi LAT Offline position.
COMMENTS:        This Notice was ground-generated -- not flight-generated.
COMMENTS:        It is the result of human-in-the-loop processing.
COMMENTS:        This is a human generated position of a LAT ground detection.
COMMENTS:        This source corresponds to GBM trigger GRB 170214A.

GCN Circular #20676
J. L. Racusin (NASA/GSFC), G. Vianello (Stanford), and J. Perkins (NASA/GSFC), report on behalf of the Fermi-LAT team:
At 15:34:26.92 on February 14, 2017, Fermi-LAT detected high-energy emission from GRB 170214A, which was also detected by Fermi-GBM (trigger 508779271 / 170214649, Mailyan et al., GCN 20675).
The best LAT on-ground location is found to be RA, Dec: 256.33, -1.88 (degrees, J2000) with an error radius of 0.08 deg (90% containment, statistical error only).
This was 33 deg from the LAT boresight at the time of the trigger, and triggered an autonomous repoint of the spacecraft.
The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the GBM emission with high significance. More than 160 photons above 100 MeV and more than 13 photons above 1 GeV are observed within 1000 seconds. The highest- energy photon is a 7.8 GeV event which is observed ~105 seconds after the GBM trigger.
A Swift ToO has been approved for this burst.
The Fermi-LAT point of contact for this burst is Judith Racusin (judith.racusin@nasa.gov).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular #20677
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Fermi/LAT GRB 170214A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020740
Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Fermi/LAT event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular #20678
D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report:
The long GRB 170214A (Fermi-GBM detection: Mailyan & Meegan, GCN 20675; Fermi-LAT detection: Racusin et al., GCN 20676) triggered Konus-Wind at T0=3D56076.276 s UT (15:34:36.276)
The light curve shows count rate increase around ~T0-50 s followed by a bright, multi-peaked structure which starts at ~T0-14 s and has a total duration of ~150 s. The emission is seen up to ~10 MeV.
As observed by Konus-Wind, the burst had a fluence of (2.41 =B1 0.17)x10^-4 erg/cm2 and a 64-ms peak energy flux, measured from T0+52.480, of (8.77 =B1 0.13)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+147.968 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha =3D -0.70 (-0.06,+0.07), the high energy photon index beta =3D -2.61 (-0.27,+0.16), the peak energy Ep =3D 330 (-19,+21) keV, chi2 =3D 96/97 dof.
The spectrum near the peak count rate (measured from T0+47.360 to T0+56.248 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha =3D -0.75 (-0.12,+0.15), the high energy photon index beta =3D -2.56 (-1.15,+0.33), the peak energy Ep =3D 412 (-68,+73) keV, chi2 =3D 110/97 dof.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170214_T56076/
All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.
GCN Circular #20679
A.P. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), A. Cholden-Brown (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU), S.L. Gibson (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 170214A (Racusin et al. GCN Circ. 20676), collecting 4.9 ks of Photon Counting (PC) mode data between T0+38.6 ks and T0+65.3 ks.
Two uncatalogued X-ray sources have been detected, however none of them is above the RASS limit or shows definitive signs of fading. Therefore, at the present time we cannot identify which, if any, is the afterglow. Details of these sources are given below:
Source 1:
```
  RA (J2000.0):  256.34147  =  17:05:21.95
  Dec (J2000.0): -1.88746  =  -01:53:14.9
  Error: 2.4 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: 0.0131 +/- 0.0021 ct s^-1   
  Distance: 49 arcsec from Fermi/LAT position.
  Flux: (4.88 +/- 0.78)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
```
Source 3:
```
  RA (J2000.0):  256.3873  =  17:05:32.95
  Dec (J2000.0): -2.0113  =  -02:00:40.8
  Error: 8.8 arcsec (radius, 90% conf.)
  Count-rate: (1.94 [+0.96, -0.74])e-3 ct s^-1	 
  Distance: 515 arcsec from Fermi/LAT position.
```
A catalogued source was also detected.
The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020740.
This circular is an official product of the Swift-XRT team.
GCN Circular #20681
Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:
We observed the field of GRB 170214A (Mailyan, et al., GCN 20675; Racusin, et al., GCN 20676) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San Pedro M=E1rtir from 2017/02 15.44 to 2017/02 15.50 UTC (10.58 to 11.99 hours after the GBM trigger). We performed a series of tiled observations partially covering the LAT error circle, obtaining a total of 0.40 hours exposure in the r and i bands and 0.32 hours exposure in the Z and Y bands.
At the position of the first Swift/XRT source (source 1; Beardmore, et al., GCN 20679), in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following detections:
```
   r    21.06 +/- 0.11
   i    20.89 +/- 0.13
   Z    20.54 +/- 0.18
   Y    20.34 +/- 0.32
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
We did not detect any significant fading during our observations, so at present we cannot confirm the nature of this source. Further observations are planned.
The second, fainter XRT source (source 3; Beardmore, et al., GCN 20679) falls outside our set of frames.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #20682
A. A. Breeveld (UCL-MSSL) and A.P. Beardmore (U. Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170214A 38603 s after the LAT trigger (Mailyan and Meegan, GCN Circ. 20675). No optical afterglow consistent with the XRT=E2=80=99s source 1 position (Beardmore et al., GCN Circ. 20679, Troja et al., GCN Circ. 20681) is detected in the initial UVOT exposures. The source 3 position is just=20 off the edge of the field of view. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for source 1 in the=20 initial exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

w1               38603        65287         4856         >21.0
```
The magnitude in the table is not corrected for the Galactic extinction due to the reddening of E(B-V) =3D 0.36 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #20683
Daniele Malesani (DARK/NBI), Jens-Kristian Krogager (IAP and DARK/NBI), and Adarsh Ranjan (IAP), report on behalf of a larger collaboration:
We observed the candidate optical counterpart of GRB 170214A (Mailyan & Meegan , GCN 20675; Racusin et al., GCN 20676; Beardmore et al., GCN 20679; Troja et al., GCN 20681) with the Nordic Optical Telescope (NOT), equipped with the AlFOSC camera. Three observations by 300 s each were taken in the SDSS r band, under a seeing of 0.7", starting on 2017 Feb 16.263 UT (38.90 hr after the Fermi/GBM trigger). We note that our pointing only covers XRT source #1 from Beardmore et al. (GCN 20679).
Within the XRT error circle (Beardmore et al., GCN 20679), we detect a single object at coordinates (0.5" error):
```
RA(J2000) = 17:05:21.90
Dec(J2000) = -01:53:15.7
```
We assume that this is the same object reported by Troja et al. (GCN 20681). Calibrating against nearby SDSS stars, we measure r = 22.45 +- 0.07 AB. The fading by more than 1 mag compared to the RATIR measurement (Troja et al., GCN 20681), as well as the spatial association with an X-ray source (Beardmore et al., GCN 20679), confirm this object to be the optical afterglow of GRB 170214A.
GCN Circular #20684
Patricia Schady and Thomas Kruehler (MPE Garching) report:
We observed the field of the Fermi GRB 170214A (trigger 508779271/170214649, Mailyan et al., GCN #20675) 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 08:53 UT on 2017-02-15, 17.3 hrs after the GRB trigger, and they were performed at an average seeing of 1.5" and at an average airmass of 1.6. We detect an uncatalogued source within the XRT error circle of Source 1 (Beardmore et al., GCN #20679), at the same position reported by Malesani et al., (GCN #20683).
Based on combined images with 16 min of total integration time in g'r'i'z' and 19 min in JHK at a mid-time of 09:05 UT on 2017-02-15, this source has the following preliminary magnitudes (all in the AB system):
g' = 22.6 +/- 0.3 mag r' = 21.3 +/- 0.1 mag i' = 20.8 +/- 0.1 mag z' = 20.3 +/- 0.1 mag J = 19.6 +/- 0.1 mag H = 19.3 +/- 0.1 mag K = 18.8 +/- 0.3 mag
We re-observed the target on 2017-02-16 at a mid-time of 08:45 UT, and the r'-band magnitude has decayed by a further 0.1 mag compared to the NOT measurement (Malesani et al., GCN #20683).
The given magnitudes are derived based on calibrating the images against SDSS in the optical and 2MASS field stars in the NIR bands. They are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)=3D 0.30 in the direction of the burst (Schlafly & Finkbeiner 2011).
We acknowledge the excellent help provided by the observer on the 2.2 m telescope at La Silla, Simona Ciceri, in obtaining these data.
GCN Circular #20685
Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FAniga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report:
We observed the field of GRB 170214A (Mailyan, et al., GCN 20675; Racusin, et al., GCN 20676) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San Pedro M=E1rtir from 2017/02 16.46 to 2017/02 16.54 UTC (43.4 to 45.4 hours after the GBM trigger), obtaining a total of 1.42 hours exposure in the r and i bands and 0.60 hours exposure in the Z and Y bands.
Source 1 (Beardmore, et al., GCN 20679; Troja, et al., GCN 20681) is still detected in our observations at a position consistent with the NOT source (Malesani, et al., GCN 20683). In comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following detections:
```
   r    22.78 +/- 0.08
   i    22.40 +/- 0.15
   Z    21.54 +/- 0.17
   Y    21.22 +/- 0.17
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
Compared to our first night of observations (Troja, et al., GCN 20681) the source significantly faded in all filters, confirming that it is the optical (Malesani, et al., GCN 20683) and NIR afterglow of GRB170214A.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #20686
T. Kruehler, P. Schady, J. Greiner (all MPE Garching) and N. R. Tanvir (U. Leicester) report:
We observed the optical counterpart (Troja et al. GCN 20681, Malesani et al. GCN 20683, Schady et al. GCN 20684) of GRB 170214A (Mailyan and Meegan, GCN 20675, Racusin et al. GCN 20676) with the ESO Very Large Telescope UT 2 (Kueyen) equipped with the X-shooter spectrograph, covering the wavelength range 3200-20000 AA. Observations started at 08:18 UT on 2017-02-16, roughly 40.7 hours after the burst and consisted of 6 exposures of 600 s each.
Our spectrum has a low signal-to-noise ratio with no signal being detected bluewards of around 5800 AA due to a combination of high background from the bright moon and faint afterglow. In the red part, the spectrum exhibits four marginal absorption features, which are consistent with coming from various FeII transitions at a common redshift of z=2.53.
We acknowledge excellent support from the ESO observing staff in Paranal, in particular Marcela Espinoza, Cedric Ledoux, and Stephane Brillant.
GCN Circular #20687
E. Mazaeva (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), A. Volnova (IKI), report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 170214A (Mailyan et al., GCN 20675; Racusin et al., GCN 20676) with AZT-33IK telescope of Sayan observatory (Mondy) starting on Feb., 15 (UT) 20:58:01. We obtained several images in R-filter. The optical counterpart of GRB 170214A (Troja et al., GCN 20681; Malesani et al., GCN 20683; Schady et al., GCN 20684) is not detected in our stacked image.
Preliminary photometry of the field is following
```
Date              UT start    t-T0        Filter  Exp.       OT      UL
                      (mid, days)                       (s)

2017-02-15 20:58:01  1.24558  R     120*30    n/d      21.4
```
Photometry is based on nearby SDSS-DR9 stars
```
SDSS-DR9_id            R(Lupton)
J170525.39-015302.5 17.50
J170522.63-015255.8 17.31
J170519.90-015220.7 18.47
J170517.04-015226.0 15.51
J170515.90-015250.9 17.81
J170518.92-015435.6 17.44
J170512.43-015325.4 16.54
J170511.57-015336.2 18.05
```
GCN Circular #20691
A.P. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), A. Cholden-Brown (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU), S.L. Gibson (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has conducted further observations of the field of the Fermi/LAT-detected burst GRB 170214A. The observations now extend from T0+38.6 ks to T0+274.4 ks.
Of the sources previously reported, "Source 1" is above the RASS limit and fading with 3-sigma significance, and is therefore likely the GRB afterglow. Using 4445 s of PC mode data and 4 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 = 256.34147, -1.88746 which is equivalent to:
```
RA (J2000): 17h 05m 21.95s
Dec(J2000): -01d 53' 14.9"
```
with an uncertainty of 2.4 arcsec (radius, 90% confidence). This position is 49 arcsec from the Fermi/LAT position. The source is fading with alpha >0.7.
The results of the XRT-team automatic analysis of the likely afterglow are at http://www.swift.ac.uk/ToO_GRBs/00020740/index_1.php. The results of the full analysis of the XRT observations are available at http://www.swift.ac.uk/ToO_GRBs/00020740.
This circular is an official product of the Swift-XRT team.

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Jochen Greiner, last update: 18-Feb-2017 [Disclaimer]