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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. No radio detection from the short GRB 080702A
  2. GRB 080702b: LCO optical observations
  3. Swift/UVOT observation of GRB080702A
  4. GRB 080702B: Swift XRT and UVOT observations
  5. GRB 080625: Suzaku WAM observation of the prompt emission
  6. GRB 080702A: MITSuME Akeno optical upper limits
  7. GRB 080701A: Early RAPTOR optical limits
  8. Swift Trigger 315630: Swift/UVOT Upper Limits
  9. GRB 080702A, Swift-BAT refined analysis
  10. GRB 080702A: Swift-XRT Team refined analysis
  11. GRB 080702B : Burst detected in BAT during Swift slew
  12. GRB 080702A: Enhanced Swift-XRT position
  13. Swift Trigger 315630: TLS R-band observation
  14. Swift Trigger 315630: Probably not a GRB
  15. GRB 080702: Swift detection of a short burst
  16. GRB 080701: Swift-XRT refined analysis
  17. GRB 080701A, VATT optical upper limit
  18. TLS I-Band Observation of GRB 080701A
  19. GRB 080701A: Swift/UVOT Upper Limits
  20. GRB 080701A: Early Super-LOTIS Observations
  21. GRB 080701: Enhanced Swift-XRT position
  22. GRB 080701A, Swift-BAT refined analysis
  23. Trigger 315630: Swift detection of a possible burst
  24. GRB 080701: Swift-XRT Prompt Analysis
  25. GRB 080701: Swift detection of a burst
  26. GRB 080623: Suzaku WAM observation of the prompt emission
  27. GRB 080625: Swift/UVOT Follow-Up Observations
  28. GRB 080625: Further observations from OSN
  29. GRB 080625:Swift-XRT detection of the afterglow
  30. GRB 080625: Swift/UVOT Detection of an Optical Afterglow
  31. GRB 080625: Observations at OSN
  32. GRB 080625: Gamma Ray Burst Localization by SuperAGILE
  33. GRB 080623: GROND upper limits
  34. GRB080623: Swift UVOT followup observations
  35. GRB 080623: Swift-XRT refined analysis
  36. GRB 080623, Swift-BAT refined analysis
  37. GRB 080623: Enhanced Swift-XRT position
  38. GRB 080623: TAROT La Silla observatory optical observations
  39. GRB 080623: Swift/UVOT Non-Detection of an Optical Afterglow
  40. GRB 080623: Swift XRT prompt analysis
  41. GRB 080623: Swift detection of a burst
  42. Swift trigger 314975 is not a GRB
  43. Swift-BAT trigger 314975 possible burst
  44. GRB080607: optical observation
  45. GRB 080603b: optical observation
  46. GRB 070809: Putative host galaxy and redshift
  47. VLA upper limit on INTEGRAL burst GRB 080613A
  48. GRB 0800603A: optical observation
  49. GRB080613B: MITSuME upper limits
  50. GRB080613A: Optical upper limits with Okayama MITSuME telescope
  51. Konus-Wind observation of GRB 080613B
  52. GRB 080603A: optical observations on June 04
  53. GRB 080613A: Swift-XRT detection of the afterglow
  54. GRB080613A: Swift/UVOT Upper Limits
  55. GRB 080613A: GROND Confirmation of the Afterglow Candidate
  56. GRB 080613B: GROND Upper Limits
  57. GRB 080613B - NOT optical and IR nondetections
  58. GRB080613B: Swift/UVOT Upper Limits
  59. GRB 080613B, Swift-BAT refined analysis
  60. GRB 080613B: Swift-XRT refined analysis
  61. GRB 080514B: Spectroscopic constraints and probable host galaxy
  62. GRB 080613B: Swift detection of a burst
  63. GRB 080613: Faulkes Telescope North optical candidate
  64. GRB 080613 : a long GRB detected with INTEGRAL
  65. GRB 080603A: Late-time Keck imaging and spectroscopy
  66. GRB 080603b: optical observation
  67. Swift observations of BAT Slew Survey event (Trigger=010)
  68. GRB 080603A: final Swift-XRT observations.
  69. GRB 080607: AGILE-MCAL observation of the prompt emission
  70. GRB 080603B - TLS 2nd Epoch: Another Break
  71. GRB 080605: TLS 3rd Epoch - Source Confusion
  72. GRB080605: optical observation with the MITSuME-OAO telescope
  73. Konus-Wind observation of GRB 080607
  74. GRB080607: RTT150 optical observations
  75. GRB 080603A: optical observations
  76. GRB 080607: Swift-XRT refined analysis
  77. Swift/UVOT Observations of GRB080607
  78. GRB 080605: optical observations
  79. GRB 080607 KAIT observations
  80. VLA detection of INTEGRAL burst GRB 080603A
  81. Konus-Wind observation of GRB 080605
  82. GRB 080607: Enhanced Swift-XRT position
  83. GRB 080607, Swift-BAT refined analysis
  84. GRB 080605: GROND 2nd epoch observations
  85. GRB 080607 - PAIRITEL NIR detection
  86. GRB 080607: Keck/LRIS spectroscopy and redshift
  87. GRB 080607: Super-LOTIS early observations
  88. GRB 080607: Swift detection of a burst with optical afterglow
  89. GRB 080607: ROTSE-III Detection of Optical Counterpart
  90. GRB 080605: TLS RRM Analysis, Plateau/Rebrightening, Red OT
  91. GRB 080605: Swift-UVOT refined analysis
  92. Possible VLA radio detection on INTEGRAL burst GRB 080603A
  93. GRB 080604: VLA radio upper limit
  94. GRB 080605, Swift-BAT refined analysis
  95. GRB 080603B: VLA radio upper limit
  96. GRB 080605, Swift-BAT refined analysis
  97. GRB 080605: Swift-XRT refined analysis
  98. GRB080605: observation by BOOTES
  99. GRB 080605: MASTER VWF 46 s AT observation
  100. GRB 080605: Enhanced Swift-XRT position

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