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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. Swift-BAT trigger 704327 was due to noise
  2. Fermi GBM trigger 490193747/160714539 is not a GRB
  3. GRB 160714A: Swift-BAT refined analysis,
  4. Swift Trigger 704327: MASTER syncronous optical observations
  5. GRB 160714A: MASTER early optical observations
  6. GRB 160712A: Further GROND observations
  7. GRB 160709A CALET Gamma-Ray Burst Monitor detection
  8. Swift Trigger 704327: a possible GRB
  9. GRB 160714A: Optical observations from OSN
  10. GRB 160714A: Swift-XRT observations
  11. GRB 160714A: Swift detection of a short burst
  12. GRB 160712A: Swift/UVOT Upper Limits
  13. GRB 160712A: RATIR Optical and NIR Observations
  14. Konus-Wind observation of GRB 160712A
  15. GRB 160712A: GROND observations
  16. GRB 160712A: Swift-XRT refined Analysis
  17. GRB 160712A: Skynet R-COP observations
  18. GRB 160712A: Enhanced Swift-XRT position
  19. GRB 160629A: 15 GHz detections and upper limits from AMI
  20. GRB 160624A: 15 GHz upper limits from AMI
  21. GRB 160712A: Initial Swift/UVOT observations
  22. GRB 160712A: Swift-XRT observations
  23. GRB 160712A: Global MASTER-Net optical observation
  24. GRB 160712A: Swift detection of a burst
  25. GRB 160625B: Global MASTER-Crimea prompt optical emission detection (fwd)
  26. GRB 160709A: MASTER early imaging Swift BAT error box
  27. GRB 160709A, Swift-BAT detection and localization
  28. GRB 160625B: TSHAO optical observations
  29. GRB 160709A: Swift-XRT observations
  30. GRB 160709A: Global MASTER Net Fermi GBM Alerts observations
  31. Konus-Wind observation of GRB 160709A (short/hard)
  32. GRB 160709A: Fermi GBM Observations
  33. GRB 160709A: Fermi-LAT detection
  34. GRB 160709A: Tiled Swift observations
  35. Fermi GBM trigger 489771293/160709649 is not a GRB
  36. GRB 160705B: TAROT Calern observatory optical observations
  37. GRB 160628A CALET Gamma-Ray Burst Monitor detection
  38. GRB 160629A: Mondy optical observations
  39. GRB 160629A: AbAO optical observations
  40. GRB 160703A: Keck-I/LRIS Optical Observations
  41. Konus-Wind observation of GRB 160702A (short/hard)
  42. IPN Triangulation of GRB 160702A (short/hard)
  43. SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections
  44. GRB 160705B: Swift/UVOT Upper Limits
  45. GRB 160705B: RATIR Optical and NIR Observations and Confirmation of the Fading Afterglow
  46. GRB 160705B: Swift-BAT refined analysis
  47. GRB 160623A: Astrosat CZTI detection
  48. GRB 160705B: Swift-XRT refined Analysis
  49. GRB 160705B: Enhanced Swift-XRT position
  50. GRB 160705B: LT optical candidate
  51. GRB 160705B: Swift detection of a burst
  52. GRB 160703A: Swift/UVOT Detection
  53. GRB 160703A: Swift-XRT afterglow detection
  54. GRB 160705A/MAXI J0748-149: MAXI/GSC detection
  55. GRB 160703A: MITSuME Ishigakijima Optical Observation
  56. GRB 160703A: MITSuME Akeno Optical Observations
  57. GRB 160625B: RTT150 optical observations
  58. GRB 160703A: Bassano Bresciano Observatory upper limits
  59. Konus-Wind observation of GRB 160703A
  60. GRB 160703A: Swift-BAT refined analysis
  61. GRB 160703A: Zadko observatory - Gingin optical observations
  62. GRB 160629A: AbAO optical observations
  63. GRB 160703A: Swift detection of a burst
  64. Swift trigger #702630 is not an astrophysical event
  65. GRB 160629A: Swift/UVOT Upper Limits
  66. GRB 160625B: SAO RAS monitoring
  67. GRB 160629A: Swift-XRT afterglow detection
  68. GRB 160625B: LCOGT FTN observations
  69. GRB 160630A: Swift-BAT refined analysis
  70. GRB 160629A: Global MASTER Net Prompt OT observations
  71. GRB 160629A: Swift ToO observations
  72. GRB 160630A: Skynet PROMPT-CTIO observations of the optical afterglow
  73. Konus-Wind observation of GRB 160629A
  74. GRB 160630A: Zadko observatory - Gingin optical observations
  75. GRB 160630A: TAROT La Silla observatory optical observations
  76. GRB 160629A: BTA and GTC redshift
  77. GRB 160630A: Swift/UVOT Upper Limits
  78. GRB 160630A: Swift-XRT refined Analysis
  79. GRB 160625A: GROND upper limits
  80. GRB 160629A: Fermi GBM observation
  81. GRB 160630A: REM NIR observations
  82. GRB 160630A: Enhanced Swift-XRT position
  83. GRB 160630A: GROND Afterglow Detection
  84. GRB 160630A: Swift detection of a burst
  85. GRB 160629A: SAO RAS independent OT detection
  86. GRB 160629A: TAROT Calern observatory optical detection
  87. GRB 160629A: a long GBB detected by INTEGRAL
  88. GRB 160625B: TSHAO optical observations, correction GCN 19619
  89. GRB 160625B: TSHAO optical observations
  90. Konus-Wind observation of GRB 160620A
  91. GRB 160625B CALET Gamma-Ray Burst Monitor detection
  92. GRB 160625B: SMARTS optical/IR afterglow observations
  93. Pi of the Sky detection of an optical flash accompanying GRB 160625B
  94. GRB 160623A: SAO RAS optical observations
  95. Konus-Wind observation of a bright burst from SGR 1935+2154
  96. GRB 160625B: Global MASTER-Net prompt optical emission detection
  97. GRB 160625B: SAO RAS optical observations
  98. GRB 160625B: 15 GHz detection from AMI
  99. GRB 160623A: Possible detection of a radio afterglow at 15 GHz with AMI
  100. GRB 160601A: 15 GHz upper limits from AMI

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