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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. GRB 080701: Swift-XRT Prompt Analysis
  2. GRB 080701: Swift detection of a burst
  3. GRB 080623: Suzaku WAM observation of the prompt emission
  4. GRB 080625: Swift/UVOT Follow-Up Observations
  5. GRB 080625: Further observations from OSN
  6. GRB 080625:Swift-XRT detection of the afterglow
  7. GRB 080625: Swift/UVOT Detection of an Optical Afterglow
  8. GRB 080625: Observations at OSN
  9. GRB 080625: Gamma Ray Burst Localization by SuperAGILE
  10. GRB 080623: GROND upper limits
  11. GRB080623: Swift UVOT followup observations
  12. GRB 080623: Swift-XRT refined analysis
  13. GRB 080623, Swift-BAT refined analysis
  14. GRB 080623: Enhanced Swift-XRT position
  15. GRB 080623: TAROT La Silla observatory optical observations
  16. GRB 080623: Swift/UVOT Non-Detection of an Optical Afterglow
  17. GRB 080623: Swift XRT prompt analysis
  18. GRB 080623: Swift detection of a burst
  19. Swift trigger 314975 is not a GRB
  20. Swift-BAT trigger 314975 possible burst
  21. GRB080607: optical observation
  22. GRB 080603b: optical observation
  23. GRB 070809: Putative host galaxy and redshift
  24. VLA upper limit on INTEGRAL burst GRB 080613A
  25. GRB 0800603A: optical observation
  26. GRB080613B: MITSuME upper limits
  27. GRB080613A: Optical upper limits with Okayama MITSuME telescope
  28. Konus-Wind observation of GRB 080613B
  29. GRB 080603A: optical observations on June 04
  30. GRB 080613A: Swift-XRT detection of the afterglow
  31. GRB080613A: Swift/UVOT Upper Limits
  32. GRB 080613A: GROND Confirmation of the Afterglow Candidate
  33. GRB 080613B: GROND Upper Limits
  34. GRB 080613B - NOT optical and IR nondetections
  35. GRB080613B: Swift/UVOT Upper Limits
  36. GRB 080613B, Swift-BAT refined analysis
  37. GRB 080613B: Swift-XRT refined analysis
  38. GRB 080514B: Spectroscopic constraints and probable host galaxy
  39. GRB 080613B: Swift detection of a burst
  40. GRB 080613: Faulkes Telescope North optical candidate
  41. GRB 080613 : a long GRB detected with INTEGRAL
  42. GRB 080603A: Late-time Keck imaging and spectroscopy
  43. GRB 080603b: optical observation
  44. Swift observations of BAT Slew Survey event (Trigger=010)
  45. GRB 080603A: final Swift-XRT observations.
  46. GRB 080607: AGILE-MCAL observation of the prompt emission
  47. GRB 080603B - TLS 2nd Epoch: Another Break
  48. GRB 080605: TLS 3rd Epoch - Source Confusion
  49. GRB080605: optical observation with the MITSuME-OAO telescope
  50. Konus-Wind observation of GRB 080607
  51. GRB080607: RTT150 optical observations
  52. GRB 080603A: optical observations
  53. GRB 080607: Swift-XRT refined analysis
  54. Swift/UVOT Observations of GRB080607
  55. GRB 080605: optical observations
  56. GRB 080607 KAIT observations
  57. VLA detection of INTEGRAL burst GRB 080603A
  58. Konus-Wind observation of GRB 080605
  59. GRB 080607: Enhanced Swift-XRT position
  60. GRB 080607, Swift-BAT refined analysis
  61. GRB 080605: GROND 2nd epoch observations
  62. GRB 080607 - PAIRITEL NIR detection
  63. GRB 080607: Keck/LRIS spectroscopy and redshift
  64. GRB 080607: Super-LOTIS early observations
  65. GRB 080607: Swift detection of a burst with optical afterglow
  66. GRB 080607: ROTSE-III Detection of Optical Counterpart
  67. GRB 080605: TLS RRM Analysis, Plateau/Rebrightening, Red OT
  68. GRB 080605: Swift-UVOT refined analysis
  69. Possible VLA radio detection on INTEGRAL burst GRB 080603A
  70. GRB 080604: VLA radio upper limit
  71. GRB 080605, Swift-BAT refined analysis
  72. GRB 080603B: VLA radio upper limit
  73. GRB 080605, Swift-BAT refined analysis
  74. GRB 080605: Swift-XRT refined analysis
  75. GRB080605: observation by BOOTES
  76. GRB 080605: MASTER VWF 46 s AT observation
  77. GRB 080605: Enhanced Swift-XRT position
  78. GRB 080605: GROND detection of the optical afterglow candidate
  79. GRB080605: optical observations
  80. GRB 080605: VLT redshift
  81. GRB 080605: Liverpool Telescope optical afterglow candidate
  82. GRB 080605: Swift/UVOT Position of the Optical Afterglow
  83. GRB 080605: TLS RRM Afterglow
  84. GRB 080605: Swift detection of a burst with an optical afterglow
  85. GRB 080603B: PAIRITEL infrared detection
  86. GRB 080603A: PAIRITEL infrared detection
  87. GRB 080604: Xinglong R band observation
  88. GRB 080603A: Xinglong R band observation
  89. GRB 080603B: TLS Afterglow Observation
  90. GRB 080603A: TLS Afterglow Observation
  91. GRB 080604: MITSuME Okayama observation
  92. Swift/UVOT observations of GRB080604
  93. GRB080604: HET redshift retraction
  94. GRB 080604: Gemini-North spectroscopy
  95. GRB 080604, Swift-BAT refined analysis
  96. GRB 080604: Swift-XRT refined analysis
  97. GRB 080603B: Hobby-Eberly Telescope redshift confirmation
  98. GRB 080603B : Xinglong EST observations
  99. GRB 080603B : Liverpool Telescope Observations
  100. Konus-Wind observation of GRB 080603B

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