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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"

28092 results found.

  1. GRB 150727A: Swift-XRT refined Analysis
  2. GRB 150727A: Enhanced Swift-XRT position
  3. GRB 150724B: Continued RATIR Optical Observations
  4. GRB 150727A: Swift detection of a burst with an optical counterpart
  5. GRB 150724B: Swift/UVOT Detection
  6. GRB 150724B: RATIR Optical Observations
  7. Swift Trigger 650408 is not a burst
  8. GRB 150724B: Swift-XRT observations
  9. IGR J00291+5934, Swift-BAT refined analysis
  10. GRB 150724B: Fermi GBM detection
  11. GRB 150724B: Fermi-LAT detection
  12. GRB 150725A: MAXI/GSC detection
  13. Trigger 650221: Swift detection of a IGR J00291+5934
  14. GRB 150724A: Swift-XRT refined Analysis
  15. Swift IGR J00291+5934: MASTER Optical flare detection
  16. GRB 150724A: Swift/UVOT Upper Limits
  17. GRB 150724A: Swift-BAT refined analysis
  18. GRB 150724A: Enhanced Swift-XRT position
  19. SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
  20. GRB 150724A: Swift detection of a burst
  21. GRB 150722A: LCOGT-Sutherland observations
  22. GRB 150722A: Swift-BAT refined analysis
  23. GRB 150722A: Swift-XRT refined Analysis
  24. GRB 150722A: Swift/UVOT Upper Limits
  25. GRB 150720A: Swift/UVOT Upper Limits
  26. GRB 150722A: Enhanced Swift-XRT position
  27. GRB 150722A: Swift-XRT observations
  28. GRB 150721A: Fermi GBM detection
  29. GRB 150720A: Enhanced Swift-XRT position
  30. GRB 150720A: Swift-XRT refined Analysis
  31. GRB 150720A: Swift-BAT refined analysis
  32. Swift Trigger 649706: a possible GRB or bright Galactic transient
  33. GRB 150711A: Burakan-ISON optical observations
  34. GRB 150716A: Swift-BAT refined analysis
  35. GRB 150716A: Swift/UVOT Upper Limits
  36. GRB 150716A: Continued RATIR Optical Observations
  37. GRB 150716A: Swift-XRT refined Analysis
  38. GRB 150716A: RATIR Optical Observations
  39. GRB 150716A: Swift detection of a burst
  40. Trigger 649113: Swift detection of SGR 1E 1841-045
  41. GRB 150710B: Swift-XRT afterglow detection
  42. GRB 150711A: Swift-BAT refined analysis
  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: Observations from the 2.5m NOT
  47. GRB 150710B refined analysis
  48. GRB 150711A: Enhanced Swift-XRT position
  49. GRB 150711A: Swift detection of a burst
  50. GRB 150710A: Swift/UVOT Upper Limits
  51. GRB 150710A: host galaxy for Swift XRT second candidate
  52. Swift-XRT observations of GRB 150710A
  53. Konus-Wind observation of GRB 150710A (Swift trigger 648437)
  54. GRB 150710A: Swift-BAT refined analysis
  55. GRB 150710A: RATIR Observations
  56. Swift trigger 648437: A GRB or a burst from 1RXS J125754.7+141850
  57. Swift Trigger 648422: Swift-XRT observations
  58. IPN Triangulation of GRB 150702A
  59. GRB 150702A: MASTER-SAAO inspection
  60. GRB 150702A: Swift-XRT observations
  61. GRB 150702A: Fermi-LAT detection
  62. GRB 150622A: Swift-XRT afterglow detection
  63. Swift Trigger 647642 is probably not an astrophysical source
  64. GRB 150626B, Swift-BAT refined analysis
  65. V404 Cyg activity (Swift, Fermi, INTGRAL, KONUS, MAXI detection): optical observations in TSHAO, Khureltogot, and AAO
  66. GRB 150627A: Swift/UVOT Detection
  67. GRB 150627A: Swift-XRT afterglow detection
  68. GRB 150626B: Swift-XRT refined Analysis
  69. GRB 150626A: Swift-BAT refined analysis
  70. GRB 150626B: Swift/UVOT Upper Limits
  71. GRB 150626B: NOT optical upper limits
  72. GRB 150626B: Enhanced Swift-XRT position
  73. GRB 150626B: Swift detection of a burst
  74. GRB 150626A: Swift-XRT refined Analysis
  75. GRB 150626A: Swift/UVOT Upper Limits
  76. GRB 150626A: Enhanced Swift-XRT position
  77. GRB 150626A: Swift detection of a burst
  78. Trigger 645944: Swift detection of H1745-203
  79. V404 Cyg: MASTER Swift, Integral alert observations
  80. GRB 150622A: Swift-XRT observations
  81. GRB 150622A: MAXI/GSC detection
  82. Swift Trigger 645340 was Sco X-1
  83. Swift Trigger 645340: a possible GRB
  84. GRB 150616A: Watcher optical upper limit
  85. Swift triggers again on V404 Cyg
  86. Swift Trigger 644520 is V404 Cyg
  87. GRB 150616A: Swift/UVOT Upper Limits
  88. GRB 150616A: Swift-BAT refined analysis
  89. V404 Cyg outburst (Swift trigger 643949 ): TSHAO optical observations
  90. GRB 150616A: Swift-XRT refined Analysis
  91. Konus-Wind observation of Galactic transient V404 Cyg in outburst
  92. GRB 150616A: Enhanced Swift-XRT position
  93. GRB 150616A: Swift detection of a burst
  94. V404 Cyg: Swift/UVOT Detection
  95. GRB 150615A, Swift-BAT refined analysis
  96. Swift trigger 643949 is V404 Cyg
  97. GRB 150615A: Swift-XRT refined Analysis
  98. GRB 150608A: Swift-XRT follow-up observations
  99. GRB 150615A: Swift/UVOT Detection
  100. GRB 150615A: Enhanced Swift-XRT position

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Download all Circulars as a .tar.gz archive (updated once a day):
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