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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').
Advanced Search

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.

Advanced Search Examples (click to copy):

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

21097 results found.

  1. LIGO/Virgo S190706ai: Coverage and upper limits from MAXI/GSC observations
  2. LIGO/Virgo S190706ai: No counterpart candidates in AGILE-MCAL observations
  3. LIGO/Virgo S190706ai Global MASTER-Net observations report
  4. Fermi trigger No 584007338 Global MASTER-Net observations report
  5. IceCube-190704A: Upper limits from Insight-HXMT/HE observations
  6. Fermi-LAT Gamma-ray Observations of IceCube-190704A and detection of the new gamma-ray source 1WHSP J104516.2+275133
  7. GRB 190627A: Discovery Channel Telescope late time observations
  8. IceCube Alert 190704.78 Global MASTER-Net observations report
  9. Baksan Neutrino Observatory Alert 190703.21 Global MASTER-Net observations report
  10. Baksan Neutrino Observatory Alert 190703.56 Global MASTER-Net observations report
  11. Fermi trigger No 583854113 Global MASTER-Net observations report
  12. LIGO/Virgo S190630ag: no counterpart candidate in the SVOM/GWAC observations
  13. LIGO/Virgo S190701ah: No transient candidates from CALET observations
  14. LIGO/Virgo S190701ah: Upper limits from Insight-HXMT/HE observations
  15. Fermi-LAT Gamma-ray Observations of IceCube-190629A
  16. LIGO/Virgo S190701ah: No counterpart candidates in the Swift/BAT Observations
  17. LIGO/Virgo S190701ah: Upper limits from AGILE-GRID observations
  18. LIGO/Virgo S190630ag: Upper limits from Insight-HXMT/HE observations
  19. LIGO/Virgo S190701ah: Upper limits from Fermi-GBM Observations
  20. LIGO/Virgo S190630ag: Upper limits from CALET observations
  21. LIGO/Virgo S190701ah Global MASTER-Net observations report
  22. LIGO/Virgo S190701ah: Coverage and upper limits from MAXI/GSC observations
  23. GRB 190701A: Swift/UVOT Upper Limits
  24. LIGO/Virgo S190701ah: No counterpart candidates in AGILE-MCAL observations
  25. GRB 190701A: COATLI Optical Observations
  26. GRB 190630C: Swift/UVOT Upper Limits
  27. GRB 190630C: KAIT Optical Upper Limit
  28. GRB 190630B: Swift/UVOT Upper Limits
  29. LIGO/Virgo S190630ag: No counterpart candidates in AGILE-GRID observations
  30. LIGO/Virgo S190630ag: No counterpart candidates in the Swift/BAT Observations
  31. LIGO/Virgo S190630ag: No counterpart candidates in AGILE-MCAL observations
  32. LIGO/Virgo S190630ag: No counterpart candidates in Fermi-LAT observations
  33. GRB 190630B: KAIT Optical Afterglow Confirmation
  34. Swift GRB190631. Global MASTER-Net observations report
  35. LIGO/Virgo S190630ag: Upper limits from Fermi-GBM Observations
  36. LIGO/Virgo S190630ag: Coverage and upper limits from MAXI/GSC observations
  37. LIGO/Virgo S190630ag: No counterpart candidates in HAWC observations
  38. LIGO/Virgo S190630ag Global MASTER-Net observations report
  39. IceCube-190629A: Upper limits from Fermi-GBM Observations
  40. GRB 190627A: VLT/FORS2 spectroscopic redshift
  41. Fermi trigger No 583567803 Global MASTER-Net observations report
  42. GRB 190627A: Koshka Zeiss-1000 optical counterpart observations
  43. Baksan Neutrino Observatory Alert 190629.56 Global MASTER-Net observations report
  44. IceCube Alert 190629.81 Global MASTER-Net observations report
  45. GRB 190627A : Xinglong 2.16m optical observation
  46. GRB 190627A: GMG observation at the second epoch
  47. GRB 190627A: NOT optical observations
  48. GRB 190627A: Optical imaging and spectroscopy from Calar Alto
  49. GRB 190627A: NUTTelA-TAO optical counterpart observations
  50. GRB 190610A: Further Swift-XRT observations
  51. GRB 190627A: MASTER optical counterpart observation
  52. GRB190627A: VIRT Afterglow observation
  53. GRB 190627A: Montarrenti Observatory optical detection
  54. GRB 190627A: NUTTelA-TAO optical observations
  55. Fermi trigger No 583327924 Global MASTER-Net observations report
  56. GRB 190627A: Swift/UVOT Detection
  57. Fermi trigger No 583245413 Global MASTER-Net observations report
  58. Fermi trigger No 583245413 Global MASTER-Net observations report
  59. Fermi trigger No 583221986 Global MASTER-Net observations report
  60. Fermi trigger No 583111521 Global MASTER-Net observations report
  61. Swift GRB190624.86 Global MASTER-Net observations report
  62. Fermi trigger No 582886211 Global MASTER-Net observations report
  63. Fermi trigger No 582856902 Global MASTER-Net observations report
  64. Fermi trigger No 582748289 Global MASTER-Net observations report
  65. Fermi trigger No 582759998 Global MASTER-Net observations report
  66. Fermi-LAT Gamma-ray Observations of IceCube-190619A
  67. LIGO/Virgo S190426c: Swift UVOT - no new counterpart candidates identified
  68. LIGO/Virgo S190510g: Swift UVOT - no new counterpart candidates identified
  69. Fermi trigger No 582615488 Global MASTER-Net observations report
  70. Fermi trigger No 582615488 Global MASTER-Net observations report
  71. Fermi trigger No 582646590 Global MASTER-Net observations report
  72. GRB 190613A: SEDM Observations
  73. Fermi trigger No 582596766 Global MASTER-Net observations report
  74. GRB 190613B: JCMT SCUBA-2 sub-mm observations
  75. Fermi trigger No 582304592 Global MASTER-Net observations report
  76. Fermi trigger No 582159815 Global MASTER-Net observations report
  77. GRB 190613B: SEDM Observations
  78. GRB 190613A: SEDM Observations
  79. GRB 190610A: Swift/UVOT Upper Limits
  80. GRB 190610A: Swift-XRT observations
  81. GRB 190613B: GROND Detection of the Optical/NIR Afterglow
  82. GRB 190613B: BOOTES-5/JGT early optical observations
  83. GRB 190613B: Optical observations from NOT
  84. Fermi trigger No 582115625 Global MASTER-Net observations report
  85. GRB 190610A: Swift ToO observations
  86. GRB 190613B: KAIT Optical Afterglow Confirmation
  87. GRB 190613B: Swift/UVOT Detection
  88. GRB 190613A: Swift/UVOT Detection
  89. Swift GRB190613.17 Global MASTER-Net observations report
  90. GRB 190613A: KAIT Optical Afterglow Confirmation
  91. Fermi trigger No 582091643 Global MASTER-Net observations report
  92. Fermi trigger No 582012834 Global MASTER-Net observations report
  93. Fermi trigger No 581986074 Global MASTER-Net observations report
  94. GRB 190611A: Swift/UVOT Upper Limits
  95. GRB 190611A: Optical observations from VLT/FORS2
  96. Fermi trigger No 582004649 Global MASTER-Net observations report
  97. Fermi trigger No 581889628 Global MASTER-Net observations report
  98. Fermi trigger No 581882394 Global MASTER-Net observations report
  99. Fermi trigger No 581841498 Global MASTER-Net observations report
  100. Fermi trigger No 581719018 Global MASTER-Net observations report

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