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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

21106 results found.

  1. HAWC-190916A: Upper limits from Fermi-GBM Observations
  2. LIGO/Virgo S190915ak: No transient candidates in CALET observations
  3. HAWC-190916A: DDOTI Optical Observations
  4. Fermi trigger No 590335819: Global MASTER-Net observations report
  5. Alert from the HAWC Burst Monitor HAWC-190917A
  6. LIGO/Virgo S190915ak: no counterpart candidates in the Swift/BAT observations
  7. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  8. LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
  9. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  10. GRB190915A: MASTER optical observation of BALROG Fermi GRB localization
  11. LIGO/Virgo S190915ak: Upper Limits from AGILE-GRID observations
  12. LIGO/Virgo S190915ak: No counterpart candidate in AGILE-MCAL observations
  13. LIGO/Virgo S190915ak: Global MASTER-Net observations report
  14. LIGO/Virgo S190910d : No significant candidates in TAROT-GRANDMA observations
  15. LIGO/Virgo S190814bv: No counterpart candidate after completion of GRAWITA VST-ESO PARANAL transient survey.
  16. Fermi trigger No 590038994: Global MASTER-Net observations report
  17. LIGO/Virgo S190910h: No counterpart candidates in Fermi-LAT observations
  18. Baksan Neutrino Observatory Alert 190913.27: Global MASTER-Net observations report
  19. LIGO/Virgo S190910d: No Counterparts in DDOTI/OAN Optical Observations
  20. LIGO/Virgo S190910h: Upper limits from CALET observations.
  21. LIGO/Virgo S190910d: No transient candidates in CALET observations.
  22. LIGO/Virgo S190910d and S190910h: No counterpart candidates in KAIT observations
  23. LIGO/Virgo S190910h: Four additional candidates from the Zwicky Transient Facility
  24. LIGO/Virgo S190910h: Candidates from the Zwicky Transient Facility
  25. LIGO/Virgo S190910d: Liverpool Telescope spectroscopy of ZTF19abyfazm
  26. LIGO/Virgo S190910h: no counterpart candidates in the Swift/BAT observations
  27. LIGO/Virgo S190910d: No counterpart candidates in Fermi-LAT observations
  28. LIGO/Virgo S190910h: No counterpart candidates in HAWC observations
  29. LIGO/Virgo S190910h: Upper limits from Fermi-GBM Observations
  30. LIGO/Virgo S190910h: No counterpart candidates in AGILE-MCAL observations
  31. LIGO/Virgo S190910h Global MASTER-Net observations report
  32. LIGO/Virgo S190910h: Coverage and upper limits from MAXI/GSC observations
  33. LIGO/Virgo S190910d: Candidates from the Zwicky Transient Facility
  34. LIGO/Virgo S190910d: no counterpart candidates in AGILE-GRID observations
  35. LIGO/Virgo S190910d: no counterpart candidates in the Swift/BAT Observations
  36. LIGO/Virgo S190910d: No counterpart candidates in AGILE-MCAL observations
  37. LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
  38. LIGO/Virgo S190910d: Upper limits from Fermi-GBM Observations
  39. LIGO/Virgo S190910d: No counterpart candidates in HAWC observations
  40. LIGO/Virgo S190910d Global MASTER-Net observations report
  41. LIGO/Virgo S190814bv: ATCA monitoring of ASKAP J005547-270433/AT2019osy
  42. LIGO/Virgo S190814bv: VLA/JAGWAR monitoring of the 50% containment region
  43. LIGO/Virgo S190901ap : No significant candidates found in GRANDMA citizen science observations
  44. Fermi trigger No 589561732 Global MASTER-Net observations report
  45. ZTF19abvizsw: 15GHz observations with AMI
  46. GRB 190829A observations in CrAO, photometry of the SN
  47. Fermi trigger No 589487114 Global MASTER-Net observations report
  48. GRB 190823A: Swift-XRT afterglow detection
  49. GRB 190829A: GTC confirmation of an associated Type Ic-BL Supernova
  50. GRB 190829A: ATCA cm-band detection
  51. LIGO/Virgo S190901ap: Second Epoch Hobby-Eberly Telescope observations of ZTF19abvionh
  52. Fermi trigger No 589419513 Global MASTER-Net observations report
  53. GRB 180620A: SEDM Observations
  54. LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations and independent transient candidates discovery.
  55. LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA
  56. LIGO/Virgo S190901ap: NOT spectroscopy of AT2019pjv
  57. LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
  58. LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv
  59. Swift XRT Detection of X-ray Emission from ZTF19abvizsw
  60. GRB 190829A: Liverpool Telescope observations of a slow supernova rise
  61. LIGO/Virgo S190901ap: Additional candidates from the Zwicky Transient Facility
  62. ZTF19abvizsw: COATLI Optical Observations
  63. LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
  64. LIGO/Virgo S190901ap: GTC follow-up spectroscopic observations of ZTF19abvizsw
  65. LIGO/Virgo S190901ap: MASTER OT J171434.95+280725.6/AT2019pjv detection
  66. LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations
  67. LIGO/Virgo S190901ap: Upper limits from CALET observations.
  68. LIGO/Virgo S190901ap: Upper limits from Insight-HXMT/HE observations
  69. Fermi trigger No 589263065 Global MASTER-Net observations report
  70. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  71. GRB 190829A: LCO Optical Afterglow Detection
  72. Fermi trigger No 589223981 Global MASTER-Net observations report
  73. GRB 190829A: MeerKAT radio observation
  74. LIGO/Virgo S190901ap: Additional observations from the Zwicky Transient Facility
  75. LIGO/Virgo S190901ap: GROWTH-India follow-up of ZTF19abvionh
  76. Chandra observations of GW170817 ~740-743 days since merger
  77. LIGO/Virgo S190901ap: Upper limits from AGILE-GRID observations
  78. LIGO/Virgo S190828l: no counterpart candidate in the SVOM/GWAC observations
  79. LIGO/Virgo S190828j: no counterpart candidate in the SVOM/GWAC observations
  80. GRB 190829A: Detection of radio afterglow with the uGMRT
  81. LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations
  82. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh [correction on the peak]
  83. GRB 190829A: Flattening of optical light curve from continued Liverpool Telescope photometry
  84. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh
  85. LIGO/Virgo S190814bv: ATCA observation of ASKAP J005547-270433/AT2019osy
  86. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of target galaxy; no obvious optical counterpart.
  87. LIGO/Virgo S190901ap: no counterpart candidates in the Swift/BAT Observations
  88. LIGO/Virgo S190901ap: Candidates from the Zwicky Transient Facility
  89. LIGO/Virgo S190901ap: No counterpart candidates in AGILE-MCAL observations
  90. LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
  91. LIGO/Virgo S190901ap: Upper limits from Fermi-GBM Observations
  92. LIGO/Virgo S190901ap Global MASTER-Net observations report
  93. LIGO/Virgo S190901ap: No counterpart candidates in HAWC observations
  94. Fermi trigger No 589065714 Global MASTER-Net observations report
  95. Fermi trigger No 589060361 Global MASTER-Net observations report
  96. LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations
  97. GRB 190829A: Continued fading inferred from Liverpool Telescope photometry
  98. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidate AT2019ntp
  99. GRB 190829A: Keck LRIS spectroscopy of the optical afterglow
  100. LIGO/Virgo S190828j : No significant candidates in TAROT-GRANDMA observations

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