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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"

21126 results found.

  1. GRB 210704A: OSIRIS/GTC Observations and Archival Detection of the Possible Host Galaxy
  2. MAXI GRB210709.93: Global MASTER-Net observations report
  3. Fermi trigger No 647522278: Global MASTER-Net observations report
  4. GRB 210704A: Gemini-North Infrared Source Detection
  5. GRB 210704A: further TNG optical observations
  6. GRB 210706A: Swift/XRT afterglow confirmation
  7. Fermi GRB 210709A: Global MASTER-Net observations report
  8. Swift GRB 210708B: Global MASTER-Net observations report
  9. GRB 210708A: Swift/UVOT Upper Limits
  10. GRB 210702A: ATCA detection
  11. GRB 210702A: ALMA detection
  12. IceCube-210629A - Spectroscopic observation of AT2021osi
  13. Konus-Wind detection of a burst from SGR 1935+2154 on 2021 July 7
  14. Swift GRB210708.10: Global MASTER-Net observations report
  15. Fermi trigger No 647365516: Global MASTER-Net observations report
  16. Fermi trigger No 647271699: Global MASTER-Net observations report
  17. Fermi GBM Observations of SGR J1935+2154
  18. GRB 210704A: OAJ T80 multi-color detections
  19. GRB 210706A: Swift-XRT afterglow detection
  20. Integral GRB210707.02: Global MASTER-Net observations report
  21. GRB 210706A: Swift ToO observations
  22. Fermi trigger No 647252274: Global MASTER-Net observations report
  23. Integral GRB210706.72: Global MASTER-Net observations report
  24. GRB 210706A: Swift/BAT-GUANO detection and arcminute localization
  25. GRB 210704A: CAHA 2.2m Afterglow Detection
  26. GRB 210704A: RATIR optical upper limits
  27. GRB 210704A: Swift/UVOT Upper Limits
  28. GRB 210619B: ALMA detection
  29. GRB 210704A: possible local hosts
  30. GRB 210704A: Swift-XRT afterglow detection
  31. GRB 210704A: Swift ToO observations
  32. Fermi trigger No 647108723: Global MASTER-Net observations report
  33. Fermi trigger No 647120009: Global MASTER-Net observations report
  34. GRB 210702A: BOOTES-3/YA optical counterpart observations
  35. GRB 210702A: Chilescope optical observations
  36. GRB 210702A: iTelescope optical afterglow observations
  37. GRB 210619B: JCMT SCUBA-2 sub-mm observations
  38. GRB 210610B: JCMT SCUBA-2 sub-mm observations
  39. GRB 210610A: JCMT SCUBA-2 sub-mm observations
  40. GRB 210702A: preliminary Swift/UVOT photometry
  41. GRB210702A: MeerLICHT multi-colour photometry
  42. Swift GRB 210702A: Global MASTER-Net observations report
  43. IceCube-210629A: One Candidate Counterpart from the Zwicky Transient Facility
  44. Fermi-LAT Gamma-ray Observations of IceCube-210629A
  45. IceCube-210629A: Upper limits from Fermi-GBM Observations
  46. IceCube Alert 210629.76: Global MASTER-Net observations report
  47. GRB 210619B: Sayan observatory 1.6-m telescope observations
  48. GRB 210626A: Swift/XRT afterglow confirmation
  49. Fermi trigger No 646443989: Global MASTER-Net observations report
  50. Fermi GRB 210627B: Global MASTER-Net observations report
  51. Fermi GRB 210627A: Global MASTER-Net observations report
  52. GRB 210626A: Swift-XRT afterglow detection
  53. Fermi trigger No 646322348: Global MASTER-Net observations report
  54. Fermi GRB 210626A: Global MASTER-Net observations report
  55. GRB 210626A: Swift ToO observations
  56. GRB 210626A: Swift/BAT-GUANO detection and arcminute localization
  57. GRB 150428A: late-time radio observations
  58. Fermi GRB 210625A: Global MASTER-Net observations report
  59. GRB210619B: optical afterglow detection from Konkoly Observatory
  60. GRB 210622A: Swift-XRT observations
  61. GRB 210610B: T-CAT optical observations
  62. Fermi trigger No 646189108: Global MASTER-Net observations report
  63. GRB 210618A: Swift-XRT afterglow detection
  64. Fermi trigger No 646194855: Global MASTER-Net observations report
  65. GRB 210622A: Swift ToO observations
  66. GRB 210619B: Even further SAO RAS optical observations
  67. GRB 210619B: Mini-MegaTORTORA early optical observations
  68. Fermi GRB 210622B: Global MASTER-Net observations report
  69. GRB 210619B: SPI-ACS/INTEGRAL observations
  70. GRB 210619B: Further SAO RAS optical observations
  71. GRB 210622A: Swift/BAT-GUANO detection and arcminute localization of a long burst
  72. GRB 210619B: AbAO optical observations
  73. Swift GRB210621.71: Global MASTER-Net observations report
  74. GRB 210619B: NOT optical observations
  75. GRB 210619B: 1.5m OSN optical observation
  76. GRB 210619B: SAO RAS optical observations
  77. GRB 210619B: SEDM Optical Observations
  78. GRB 210619B: TNG NIR observations of the afterglow
  79. GRB 210619B: REM optical/NIR afterglow detection
  80. Fermi GRB 210621A: Global MASTER-Net observations report
  81. GRB 210619B: GIT optical follow-up and confirmation of jet-break
  82. GRB 210619B: Liverpool Telescope First Hour Observations
  83. GRB 210619B: Swift/UVOT Detection
  84. GRB 210619B: Xinglong TNT optical observations
  85. GRB 210619B: CAHA 2.2m photometric monitoring
  86. GRB 210619B: Liverpool Telescope r'-band observations
  87. GRB 210619B: Redshift from OSIRIS/GTC
  88. Fermi trigger No 645857659: Global MASTER-Net observations report
  89. GRB 210619B: Ondrejov D50 detection
  90. Swift GRB210619.99: Global MASTER-Net observations report
  91. GRB 210618A: Swift/UVOT Upper Limits
  92. GRB 210618A: Swift-XRT observations
  93. Swift GRB210618.07: Global MASTER-Net observations report
  94. GRB 210610B: Swift/UVOT Detection
  95. GRB 210610A: Swift/UVOT Detection
  96. GRB 210610B: CrAO/ZTSH continued optical observations and light curve
  97. Fermi trigger No 645485036: Global MASTER-Net observations report
  98. GRB 210610B: AbAO optical observations
  99. Fermi GRB 210615A: Global MASTER-Net observations report
  100. GRB 210610B: REM optical/NIR observations of the afterglow

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