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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. IPN Triangulation of GRB 111215B (long/intense)
  2. GRB111215A: Pre-Outburst Palomar 48 inch Imaging
  3. GRB 111215A: WHT, LT and NOT imaging
  4. GRB 111215A: TNG K-band observations
  5. GRB 111215A: MITSuME Okayama Optical upper limits
  6. GRB 111215A: Swift/UVOT Upper Limits
  7. GRB 111215A: Swift-XRT refined Analysis
  8. Possible detection of pre-trigger X-ray emission from GRB 111215A by MAXI/GSC
  9. GRB 111215A: Enhanced Swift-XRT position
  10. GRB 111215A: Swift-BAT refined analysis
  11. GRB 111215A: OSN I-band observations
  12. GRB 111215A: MASTER-Net optical prompt and follow up observations
  13. GRB 111215A, Optical Observations
  14. GRB 111215A: MITSuME Akeno Optical upper limits
  15. GRB 111209A: RAPTOR Limits Before and During the Gamma-ray Emitting Interval
  16. GRB 111215A: GMG optical upper limit
  17. GRB 111215A : Xinglong TNT upper limit
  18. GRB 111215A: Swift detection of a burst
  19. GRB 111201A, the review of the sky area in plate archive
  20. GRB 111212A: GROND observations
  21. GRB 111211A: Swift/UVOT Detection
  22. GRB 111211A: VLT/X-shooter redshift
  23. Konus-Wind observation of GRB 111211A
  24. GRB 111211A: NOT afterglow confirmation
  25. GRB 111212A: Swift-XRT refined Analysis
  26. GRB 111211A: Swift/XRT target of opportunity observation
  27. GRB 111212A: Swift/UVOT Upper Limits
  28. GRB 111212A: Swift-BAT refined analysis
  29. GRB 111212A: Enhanced Swift-XRT position
  30. GRB 111212A: Swift-XRT observations
  31. GRB 111211A: GROND afterglow candidate
  32. GRB 111212A: Swift detection of a burst
  33. GRB 111211A: SuperAGILE localization of a long GRB
  34. GRB 111210A: Xinglong TNT upper limit
  35. GRB 111209A - ATCA 34GHz upper limit
  36. Konus-Wind observation of GRB 111209A
  37. GRB 111210A: GROND observations
  38. GRB 111210A: SDSS prior imaging
  39. GRB 111210A: Swift-XRT refined Analysis
  40. GRB 111210A: MITSuME Okayama Optical upper limits
  41. GRB 111208A: Swift-XRT refined analysis
  42. GRB 111210A: Gemini-North candidate counterpart
  43. GRB 111209A: Rebrightening seen by GROND
  44. GRB111210A: MITSuME Okayama J-band upper-limit
  45. GRB 111210A: Swift/UVOT Upper Limits
  46. GRB 111210A: Spectral lag analysis
  47. GRB 111210A: Enhanced Swift-XRT position
  48. GRB 111210A: Swift-BAT refined analysis
  49. GRB 111210A: Swift detection of a burst
  50. GRB 111209A: IRTF NIR Imaging/Spectroscopy
  51. GRB 111209A: VLT/X-shooter redshift
  52. GRB 111209A: GROND Afterglow observations
  53. GRB 111209A optical limit by "Pi of the Sky"
  54. GRB 111209A: PROMPT optical observations of early afterglow
  55. GRB 111208A: Lightbuckets Optical Observations
  56. GRB 111209A: Swift-XRT refined Analysis
  57. GRB 111209A: Swift UVOT refined analysis
  58. GRB 111209A: Swift Burst of Interest
  59. GRB 111209A, Swift-BAT refined analysis
  60. GRB 111209A: Enhanced Swift-XRT position
  61. GRB111209A : planned XMM-Newton observation
  62. GRB 111209A: TAROT La Silla observatory optical light curve analysis
  63. GRB 111205A: GROND observations
  64. GRB 111209A: Faulkes Telescope North observations
  65. GRB 111209A: REM NIR detection
  66. GRB 111209A: TAROT La Silla observatory optical detection
  67. GRB 111209A: Swift detection of a long burst with an optical counterpart
  68. GRB 111208A: Swift XRT/UVOT observations
  69. GRB 111205A: Swift XRT Observations
  70. GRB 111207A found in ground analysis of BAT data
  71. GRB 111208A found in ground analysis of BAT data
  72. Konus-Wind observation of GRB 111205A
  73. IPN Triangulation of GRB 111205A (long/hard/intense)
  74. GRB 111117A: Refined GMG observation
  75. GRB 111204A: TNG NIR observations
  76. GRB 111201A: GMG optical observation
  77. GRB 111204A: GROND Observations
  78. GRB 111204A: Swift-XRT refined Analysis
  79. GRB 111204A, Swift-BAT refined analysis
  80. GRB 111022B: CrAO optical limit
  81. GRB 111204A: Swift/UVOT Upper Limits
  82. GRB 110921A: optical observations in Maidanak observatory
  83. GRB 111204A: MASTER optical observations
  84. GRB 111123A: optical upper limit in CrAO: correction to the GCN circ. 12613
  85. GRB 111204A: Enhanced Swift-XRT position
  86. GRB 111123A: optical upper limit in CrAO
  87. GRB 111204A: Swift detection of a burst
  88. GRB 111201A: Confirmation of the X-ray afterglow
  89. GRB 111201A: Swift/UVOT Upper Limits
  90. GRB111201A: Swift-XRT observations
  91. GRB 111201A found in ground analysis of BAT data
  92. GRB 111121A: Suzaku WAM observation of the prompt emission
  93. GRB 111129A: Swift/UVOT Detection
  94. GRB 111129A, GROND afterglow observations
  95. GRB 111129A: Swift-XRT refined Analysis
  96. GRB 111126A Circular #12599 erratum
  97. GRB 111129A: Swift-BAT refined analysis
  98. GRB 111129A: Enhanced Swift-XRT position
  99. GRB 111129A: Swift detection of a burst with an optical counterpart
  100. GRB 111126A found in ground analysis of BAT data

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