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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"
  1. Correction to GCN 18059: Parameterisation of Swift-XRT light curve
  2. GRB 150724A: Swift-XRT refined Analysis
  3. Swift IGR J00291+5934: MASTER Optical flare detection
  4. GRB 150724A: Swift/UVOT Upper Limits
  5. IGR J00291+5934: Swift-BAT refined analysis
  6. GRB 150724A: Swift-BAT refined analysis
  7. GRB 150724A: Enhanced Swift-XRT position
  8. SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
  9. GRB 150724A: Prompt enhanced Swift-XRT position
  10. Trigger 650140: Swift detection of IGR J00291+5934
  11. GRB 150724A: Swift detection of a burst
  12. GRB 150722A: LCOGT-Sutherland observations
  13. GRB 150722A: Swift-BAT refined analysis
  14. GRB 150722A: Swift-XRT refined Analysis
  15. GRB 150722A: Swift/UVOT Upper Limits
  16. GRB 150720A: Swift/UVOT Upper Limits
  17. GRB 150722A: Enhanced Swift-XRT position
  18. GRB 150722A: Swift-XRT observations
  19. GRB 150722A: Swift detection of a burst
  20. GRB 150721A: Fermi GBM detection
  21. GRB 150720A: Enhanced Swift-XRT position
  22. GRB 150720A: Swift-XRT refined Analysis
  23. GRB 150720A: Swift-BAT refined analysis
  24. Swift Trigger 649706: a possible GRB or bright Galactic transient
  25. GRB 150716A: KAIT Optical Upper Limit
  26. GRB 150711A: Burakan-ISON optical observations
  27. GRB 150716A: Swift-BAT refined analysis
  28. GRB 150716A: Swift/UVOT Upper Limits
  29. GRB 150716A: Continued RATIR Optical Observations
  30. Swift trigger 649143 is not AX J1619.4-4945 or other astrophysical source
  31. GRB 150716A: Swift-XRT refined Analysis
  32. GRB 150716A: P60 Candidate Optical Afterglow
  33. GRB 150716A: RATIR Optical Observations
  34. GRB 150716A: Swift detection of a burst
  35. Fermi GBM triggers bn150715759 and bn150715817 are not due to GRBs
  36. Trigger 649143: Swift detection of AX J1619.4-4945
  37. Trigger 649113: Swift detection of SGR 1E 1841-045
  38. Fermi Gamma-ray Burst Monitor triggers that are not GRBs
  39. GRB 150710B: Swift-XRT afterglow detection
  40. Fermi GBM trigger 458312518/150711543 is not a GRB
  41. GRB 150711A: Swift-BAT refined analysis
  42. Konus-Wind observation of GRB 150710B
  43. GRB 150710B: Swift-XRT and Swift-UVOT observations
  44. GRB 150711A: Swift/UVOT Upper Limits
  45. GRB 150711A: Swift-XRT refined Analysis
  46. GRB 150711A: Fermi GBM detection
  47. GRB 150711A: Observations from the 2.5m NOT
  48. GRB 150710B refined analysis
  49. GRB 150711A: Enhanced Swift-XRT position
  50. GRB 150711A: Swift detection of a burst
  51. GRB 150710B: Swift ToO observations
  52. GRB 150710B detected in ground analysis of BAT data
  53. GRB 150710A: Swift/UVOT Upper Limits
  54. MASTER OT Detection during Fermi Trigger 458235025 inspection
  55. GRB 150710A: host galaxy for Swift XRT second candidate
  56. Swift-XRT observations of GRB 150710A
  57. Confirmation that Swift trigger 648422 is not an astrophysical source
  58. Konus-Wind observation of GRB 150710A (Swift trigger 648437)
  59. GRB 150710A: Swift-BAT refined analysis
  60. GRB 150710A: RATIR Observations
  61. Swift trigger 648437: A GRB or a burst from 1RXS J125754.7+141850
  62. Swift Trigger 648422: Swift-XRT observations
  63. Trigger 648422: Swift possible detection of a source in NGC4552
  64. GRB 150626B: AMI 16 GHz detection of the radio counterpart
  65. Fermi Gamma-ray Burst Monitor Trigger bn150705731 is not a GRB
  66. Konus-Wind observation of GRB 150702A
  67. GRB 150702A: Fermi GBM detection
  68. IPN Triangulation of GRB 150702A
  69. GRB 150702A: MASTER-SAAO inspection
  70. GRB 150702A: Swift-XRT observations
  71. GRB 150702A: Swift ToO observations
  72. GRB 150702A: Fermi-LAT detection
  73. Fermi GBM Observations is no longer triggerin on V404 Cyg
  74. GRB 150622A: Swift-XRT afterglow detection
  75. Swift Trigger 647642 is probably not an astrophysical source
  76. Fermi Gamma-ray Burst Monitor Trigger 150626873 is not a GRB
  77. Fermi Gamma-ray Burst Monitor Trigger bn150628857 is not a GRB
  78. Fermi Gamma-ray Burst Monitor trigger bn150629779 is not a GRB
  79. Konus-Wind observation of GRB 150627A
  80. GRB 150626B, Swift-BAT refined analysis
  81. V404 Cyg activity (Swift, Fermi, INTGRAL, KONUS, MAXI detection): optical observations in TSHAO, Khureltogot, and AAO
  82. GRB 150627A: corection to 17978
  83. GRB 150627A: MASTER-SAAO OT Detection
  84. GRB 150627A: Swift/UVOT Detection
  85. GRB 150627A: Swift-XRT afterglow detection
  86. GRB 150627A: Fermi GBM observation
  87. GRB 150626B: Swift-XRT refined Analysis
  88. GRB 150626A: Swift-BAT refined analysis
  89. GRB 150627A: Swift ToO observations
  90. GRB 150627A: Fermi-LAT detection
  91. GRB 150626B: Swift/UVOT Upper Limits
  92. GRB 150626B: NOT optical upper limits
  93. GRB 150626B: Enhanced Swift-XRT position
  94. GRB 150626B: MASTER observations
  95. GRB 150626B: Swift detection of a burst
  96. GRB 150626A: Swift-XRT refined Analysis
  97. GRB 150626A: Swift/UVOT Upper Limits
  98. Trigger 646721: Swift detection of V 404 Cyg
  99. GRB 150626A: Enhanced Swift-XRT position
  100. GRB 150626A: Prompt enhanced Swift-XRT position

Advanced

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