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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"

19670 results found.

  1. GRB 210731A: GROND observations
  2. GRB 210731A: Fermi GBM Observation
  3. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  4. Swift GRB210731.62: Global MASTER-Net observations report
  5. GRB 210731A: MeerLICHT optical afterglow detection
  6. GRB210731A: Enhanced Swift-XRT position
  7. GRB 210731A: Swift detection of a burst
  8. Swift GRB210731.93: Global MASTER-Net observations report
  9. Trigger 1062273: Swift detection of 4U 1700-377
  10. GRB 210730A: BOOTES-5/JGT and 2.2m CAHA telescopes optical limit
  11. Swift GRB 210730A: Global MASTER-Net observations report
  12. GRB 210726A: Chandra detection of the X-ray afterglow
  13. GRB 210730A: Fermi GBM observation
  14. GRB 210730A: AstroSat CZTI detection
  15. GRB 210730A: Swift-BAT refined analysis
  16. GRB 210730A: Swift-XRT refined Analysis
  17. GRB 210730A: Swift/UVOT Upper Limits
  18. GRB 210730A: Enhanced Swift-XRT position
  19. GRB 210730A: Swift detection of a burst near M82
  20. GRB 210724A: Corrected Swift-XRT enhanced position
  21. Fermi GBM Sub-Threshold Detection of GRB 210725B
  22. IPN triangulation of GRB 210727A (short)
  23. Fermi GBM Sub-Threshold Detection of GRB 210726A
  24. GRB 210726A: Swift-XRT refined Analysis
  25. GRB 210726A: Swift-BAT refined analysis
  26. GRB 210726A: Likely a short burst
  27. GRB 210726A: RATIR Optical Upper Limits and Candidate Host Galaxy
  28. GRB 210724A: Swift/UVOT Upper Limits
  29. GRB 210723A: Swift/UVOT Upper Limits
  30. GRB 210725A: Swift/UVOT Upper Limits
  31. GRB 210725B: Swift/UVOT Upper Limits
  32. GRB 210726A: CAHA 2.2m telescope optical limit
  33. GRB 210726A: Enhanced Swift-XRT position
  34. GRB 210726A: Swift detection of a burst
  35. Swift GRB210726.80: Global MASTER-Net observations report
  36. GRB 210725B: Swift-XRT refined Analysis
  37. GRB 210725A: Fermi GBM detection
  38. GRB 210725A: Swift-XRT refined Analysis
  39. GRB 210725B: Swift-BAT refined analysis
  40. GRB 210724A: Swift-XRT refined Analysis
  41. GRB 210725A: Swift-BAT refined analysis
  42. GRB 210724A: Swift-BAT refined analysis
  43. Swift GRB 210725B: Global MASTER-Net observations report
  44. GRB 210725B: Enhanced Swift-XRT position
  45. GRB 210725A: MITSuME Akeno optical upper limits
  46. GRB 210725B: Swift detection of a burst
  47. GRB 210725A: CALET Gamma-Ray Burst Monitor detection
  48. GRB 210723A: CALET Gamma-Ray Burst Monitor detection
  49. GRB 210725A: KAIT Optical Upper Limit
  50. GRB 210725A: Swift detection of a burst
  51. Swift GRB210725.16: Global MASTER-Net observations report
  52. GRB 210723A: Fermi GBM Observation
  53. GRB210724A: MeerLICHT upper limits
  54. GRB 210724A: Swift detection of a burst
  55. Swift GRB210724.84: Global MASTER-Net observations report
  56. GRB 210723A: Swift-BAT refined analysis
  57. GRB 210723A: Swift-XRT refined Analysis
  58. Swift GRB 210723A: Global MASTER-Net observations report
  59. GRB 210722A: Fermi GBM observation
  60. GRB 210722A: Swift-BAT refined analysis
  61. GRB 210723A: Prompt enhanced Swift-XRT position
  62. GRB 210723A: Swift detection of a burst
  63. GRB 210722A: Swift-XRT refined Analysis
  64. GRB 210722A: Swift/UVOT Detection
  65. GRB 210722A: GIT optical detection and preliminary analysis
  66. Swift GRB 210722A: Global MASTER-Net observations report
  67. GRB 210722A: Nanshan/NEXT optical afterglow observations
  68. GRB 210722A: Swift detection of a burst with a bright optical counterpart
  69. GRB 210712A: Swift-BAT refined analysis
  70. GRB 210712A: Swift-XRT refined Analysis
  71. GRB 210712A: Swift/UVOT Upper Limits
  72. GRB 210712A: BOOTES-3/YA optical upper limit
  73. GRB 210712A: Enhanced Swift-XRT position
  74. GRB 210712A: Swift detection of a burst
  75. GRB210704A: Gemini near-infrared upper limits
  76. GRB 210706A: Swift/XRT afterglow confirmation
  77. GRB 210708B: Swift-BAT refined analysis
  78. Swift GRB 210708B: Global MASTER-Net observations report
  79. GRB 210708A: Swift/UVOT Upper Limits
  80. GRB 210708A: Swift-BAT refined analysis
  81. Fermi GBM Sub-Threshold Detection of GRB 210708A
  82. GRB 210708B: Swift detection of a possible burst
  83. GRB 210708A: Swift-XRT refined Analysis
  84. GRB 210708A: Swift detection of a burst
  85. Swift GRB210708.10: Global MASTER-Net observations report
  86. GRB 210704A: CAHA 2.2m telescope optical limit
  87. Fermi GBM Observations of SGR J1935+2154
  88. Swift-BAT detection of a burst from SGR 1935+2154
  89. GRB 210706A: Fermi GBM observation
  90. GRB 210706A: optical upper limit of Sintesz-Newton/CrAO and AS-32/AbAO
  91. Konus-Wind detection of GRB 210706A
  92. GRB 210706A: GIT optical upper limits
  93. GRB 210704A: OAJ T80 multi-color detections
  94. GRB 210706A: Swift-XRT afterglow detection
  95. GRB 210706A: Swift ToO observations
  96. GRB 210706A: Swift/BAT-GUANO detection and arcminute localization
  97. GRB 210704A: OSIRIS/GTC spectroscopy
  98. GRB 210704A: CAHA 2.2m Afterglow Detection
  99. GRB 210704A: Swift/UVOT Upper Limits
  100. GRB 210704A: Assy optical afterglow candidate

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