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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 080707: Swift detection of a burst
  2. Refined analysis of Swift Trigger 316063, is IGR J08408-4503
  3. Trigger 316063: Swift detection of a transient
  4. GRB 080703: GROND Upper Limits
  5. GRB 080702B: GROND Upper Limits
  6. GRB 080703: Swift-XRT refined analysis
  7. GRB 080703: UVOT Follow-Up Observation
  8. GRB 080703: VLT observations of the afterglow
  9. GRB 080703: Enhanced Swift-XRT position
  10. GRB 080703, Swift-BAT refined analysis
  11. GRB 080702B Swift-BAT refined analysis
  12. GRB 080703: Swift detection of a burst with optical afterglow
  13. GRB 080703A: ROTSE-III Detection of Optical Counterpart
  14. No radio detection from the short GRB 080702A
  15. GRB 080702b: LCO optical observations
  16. Swift/UVOT observation of GRB080702A
  17. GRB 080702B: Swift XRT and UVOT observations
  18. GRB 080625: Suzaku WAM observation of the prompt emission
  19. GRB 080702A: MITSuME Akeno optical upper limits
  20. GRB 080701A: Early RAPTOR optical limits
  21. Swift Trigger 315630: Swift/UVOT Upper Limits
  22. GRB 080702A, Swift-BAT refined analysis
  23. GRB 080702A: Swift-XRT Team refined analysis
  24. GRB 080702B : Burst detected in BAT during Swift slew
  25. GRB 080702A: Enhanced Swift-XRT position
  26. Swift Trigger 315630: TLS R-band observation
  27. Swift Trigger 315630: Probably not a GRB
  28. GRB 080702: Swift detection of a short burst
  29. GRB 080701: Swift-XRT refined analysis
  30. GRB 080701A, VATT optical upper limit
  31. TLS I-Band Observation of GRB 080701A
  32. GRB 080701A: Swift/UVOT Upper Limits
  33. GRB 080701A: Early Super-LOTIS Observations
  34. GRB 080701: Enhanced Swift-XRT position
  35. GRB 080701A, Swift-BAT refined analysis
  36. Trigger 315630: Swift detection of a possible burst
  37. GRB 080701: Swift-XRT Prompt Analysis
  38. GRB 080701: Swift detection of a burst
  39. GRB 080623: Suzaku WAM observation of the prompt emission
  40. GRB 080625: Swift/UVOT Follow-Up Observations
  41. GRB 080625: Further observations from OSN
  42. GRB 080625:Swift-XRT detection of the afterglow
  43. GRB 080625: Swift/UVOT Detection of an Optical Afterglow
  44. GRB 080625: Observations at OSN
  45. GRB 080625: Gamma Ray Burst Localization by SuperAGILE
  46. GRB 080623: GROND upper limits
  47. GRB080623: Swift UVOT followup observations
  48. GRB 080623: Swift-XRT refined analysis
  49. GRB 080623, Swift-BAT refined analysis
  50. GRB 080623: Enhanced Swift-XRT position
  51. GRB 080623: TAROT La Silla observatory optical observations
  52. GRB 080623: Swift/UVOT Non-Detection of an Optical Afterglow
  53. GRB 080623: Swift XRT prompt analysis
  54. GRB 080623: Swift detection of a burst
  55. Swift trigger 314975 is not a GRB
  56. Swift-BAT trigger 314975 possible burst
  57. GRB080607: optical observation
  58. GRB 080603b: optical observation
  59. GRB 070809: Putative host galaxy and redshift
  60. VLA upper limit on INTEGRAL burst GRB 080613A
  61. GRB 0800603A: optical observation
  62. GRB080613B: MITSuME upper limits
  63. GRB080613A: Optical upper limits with Okayama MITSuME telescope
  64. Konus-Wind observation of GRB 080613B
  65. GRB 080603A: optical observations on June 04
  66. GRB 080613A: Swift-XRT detection of the afterglow
  67. GRB080613A: Swift/UVOT Upper Limits
  68. GRB 080613A: GROND Confirmation of the Afterglow Candidate
  69. GRB 080613B: GROND Upper Limits
  70. GRB 080613B - NOT optical and IR nondetections
  71. GRB080613B: Swift/UVOT Upper Limits
  72. GRB 080613B, Swift-BAT refined analysis
  73. GRB 080613B: Swift-XRT refined analysis
  74. GRB 080514B: Spectroscopic constraints and probable host galaxy
  75. GRB 080613B: Swift detection of a burst
  76. GRB 080613: Faulkes Telescope North optical candidate
  77. GRB 080613 : a long GRB detected with INTEGRAL
  78. GRB 080603A: Late-time Keck imaging and spectroscopy
  79. GRB 080603b: optical observation
  80. Swift observations of BAT Slew Survey event (Trigger=010)
  81. GRB 080603A: final Swift-XRT observations.
  82. GRB 080607: AGILE-MCAL observation of the prompt emission
  83. GRB 080603B - TLS 2nd Epoch: Another Break
  84. GRB 080605: TLS 3rd Epoch - Source Confusion
  85. GRB080605: optical observation with the MITSuME-OAO telescope
  86. Konus-Wind observation of GRB 080607
  87. GRB080607: RTT150 optical observations
  88. GRB 080603A: optical observations
  89. GRB 080607: Swift-XRT refined analysis
  90. Swift/UVOT Observations of GRB080607
  91. GRB 080605: optical observations
  92. GRB 080607 KAIT observations
  93. VLA detection of INTEGRAL burst GRB 080603A
  94. Konus-Wind observation of GRB 080605
  95. GRB 080607: Enhanced Swift-XRT position
  96. GRB 080607, Swift-BAT refined analysis
  97. GRB 080605: GROND 2nd epoch observations
  98. GRB 080607 - PAIRITEL NIR detection
  99. GRB 080607: Keck/LRIS spectroscopy and redshift
  100. GRB 080607: Super-LOTIS early observations

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