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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"

3393 results found.

  1. IPN Triangulation of GRB 141118A
  2. Swift Trigger 618402: probable noise event
  3. GRB 141109A: MITSuME Ishigakijima upper limits
  4. GRB 141109B: Swift-BAT refined analysis
  5. Konus-Wind observation of GRB 141102A
  6. GRB 141029A: MAXI/GSC detection
  7. GRB 141028A: Fermi GBM detection
  8. GRB 141028A: Fermi-LAT detection
  9. GRB 141020A: Mondy optical observations
  10. GRB 141017A: Swift detection of a burst
  11. GRB 141004A: Fermi GBM observation
  12. GRB 141005A: P60 probable afterglow deteaction
  13. GRB 140928A: MAXI-GSC detection
  14. GRB 140930B: MASTER early optical observations
  15. GRB 140928A: Fermi GBM detection
  16. GRB 140928A: Fermi-LAT detection
  17. GRB 140916B: iPTF Optical Observations
  18. GRB 140907A: Continued DCT Observations
  19. GRB 140907A : Optical observations from Nanshan
  20. GRB 140828A: Fermi GBM observation
  21. GRB 140824A: Swift detection of a burst
  22. Fermi trigg_num 430148973: bright OT inside large error box!
  23. GRB 140818A: Correction to GCN 16702
  24. GRB 140808A: optical afterglow candidate iPTF14eag
  25. GRB 140713A: 10.4-m GTC deep optical observation
  26. GRB 140706A: Swift-BAT refined analysis
  27. Pre-discovery observations of SGR 1935+2154 in Swift archival data
  28. GRB 140629A: SAO RAS monitoring
  29. Fermi 425667201: optical counterpart search
  30. Swift Trigger 602668 is probably not an astrophysical source
  31. Fermi 423717114: Additional P48 and P60 observations
  32. GRB 140528A: Fermi GBM Detection
  33. Konus-Wind observation of GRB 140529A
  34. GRB 140529A found in ground analysis of BAT slew data
  35. Swift detection of SFXT IGR J17544-2619
  36. IPN Triangulation of GRB 140523A
  37. Swift trigger 599860 probably not real
  38. GRB 140521A: AAO optical observations
  39. GRB 140518A: P60 i-/z-band detections
  40. GRB 140515B: MAXI/GSC detection
  41. GRB 140512A: Mondy optical detection
  42. GRB 140512A: MASTER optical observations
  43. GRB 140509B: MAXI/GSC detection
  44. GRB 140428B: Fermi GBM observation
  45. Trigger 597570: Swift detection of SGR 1806-20
  46. GRB 140428A: Keck detection of a red optical afterglow candidate
  47. GRB 140423A: MITSuME Akeno Optical observation
  48. Konus-Wind observation of GRB 140416A
  49. Swift Trigger 595345 is not an astrophysical source
  50. Swift trigger 594286: Is likely a noise trigger
  51. Retraction of the Fermi/LAT high-energy counterpart for GRB 140330A
  52. Konus-Wind observation of GRB 140330A
  53. Konus-Wind observation of GRB 140329A
  54. Fermi Gamma-ray Burst Monitor trigger 417486540 / 140326020 is not a GRB
  55. GRB 140226A/iPTF14yb: Mondy optical observations
  56. IPN Triangulation of very intense GRB 140320D
  57. GRB 140320A: Swift-BAT refined analysis
  58. GRB 140320C: Swift-XRT detection of the X-ray afterglow
  59. GRB 140320A: Fermi GBM observations suggest a short GRB
  60. GRO J1744-28: Fermi GBM observation
  61. IPN Triangulation of GRB 140308A
  62. GRB 140304A: VLA Detection
  63. GRB 140304A: Swift-BAT refined analysis
  64. GRB 140304A: Enhanced Swift-XRT position
  65. GRB 140304A: Swift detection of a burst
  66. Konus-Wind observation of GRB 140215A
  67. Trigger 586482: Swift detection of GROJ1744-28
  68. GRB 140209A: Swift-BAT Spectral lag analysis
  69. GRB 140209A: Swift detection of a burst
  70. GRB 140129B: MASTER OT early light curve
  71. GRB 140129A: P60 optical afterglow detection
  72. GRB 140103A: AAO optical afterglow candidate
  73. Swift-BAT trigger 582894 is HR 1099 (Flare star)
  74. GRB 140103A: Swift-XRT refined analysis
  75. GRB 140102A: MAXI/GSC detection
  76. GRB 131231A: P60 observations
  77. Konus-Wind observation of GRB 131229A
  78. GRB 131229A: CARMA 3mm observations
  79. GRB 131227A: GROND Upper Limits
  80. GRB 131227A: Enhanced Swift-XRT position
  81. GRB 131227A: OT candidate from KAIT Optical observations
  82. Trigger 581129: Swift-BAT triggered on noise
  83. GRB 131127B: rejection of optical counterpart candidates
  84. GRB 131128A; Fermi GBM observation
  85. GRB 131128A: AROMA-N Optical Observation
  86. GRB 131128A: T100 observations
  87. GRB 131128A: MASTER-Net optical observations
  88. GRB 131127B: Nanshan optical observations
  89. IPN Triangulation of GRB 131127B
  90. Fermi407254341: iPTF optical afterglow candidates
  91. GRB 131122A: Nanshan optical upper limit
  92. GRB 131108A: 1.23m CAHA optical candidate
  93. GRB 131028A: Fermi GBM detection
  94. GRB 131024A: Skynet R-COP optical observations
  95. GRB 131024A: Swift detection of a burst
  96. GRB 131014A: Suzaku WAM observation of the prompt emission
  97. GRB 131002B: Swift detection of a burst
  98. GRB 130925A: continuing Swift/XRT monitoring
  99. GRB 130702A: RTT150 optical observations
  100. GRB 130913A detected in ground analysis of Swift-BAT data

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