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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 071208?: Swift detection of a possible burst
  2. IBAS Alert #4772 in not a GRB
  3. GRB 071125: Suzaku WAM observation of the prompt emission
  4. GRB 070429B: Probable host galaxy and redshift
  5. GRB 071129, Swift-BAT refined analysis
  6. GRB 071129: Swift detection of a burst
  7. Konus-Wind and Konus-A observations of GRB 071125
  8. IPN triangulation of very bright GRB 071125
  9. GRB 071112C: Optical/NIR observations
  10. Disregard the "GRB 071126" position
  11. GRB 071126: Enhanced Swift-XRT position
  12. VLA radio detection of GRB 071122
  13. GRB071122: Swift/UVOT Observations
  14. GRB071104: NIR Afterglow Candidate at TNG
  15. GRB 071122: MASTER optical observation
  16. GRB 071122, Swift-BAT refined analysis
  17. GRB 071122 Swift XRT position update sent in error.
  18. GRB 071122 Swift-XRT refined analysis
  19. GRB 071122: Corrected P60 Coordinates
  20. GRB071122: Gemini Absorption redshift
  21. GRB 071122: P60 Optical Afterglow Candidate
  22. GRB 071122: ROTSE-III Optical Limits
  23. GRB 071122: Swift detection of a burst
  24. GRB 071118: P60 Observations
  25. GRB071118 MITSuME OAO optical observation
  26. GRB 071118: Observations from OSN
  27. GRB 071117: VLT observations and probable redshift
  28. Swift/UVOT observations of GRB071118
  29. GRB 071117: Swift-XRT revised position
  30. Konus-Wind and Konus-A observations of GRB 071117
  31. Swift XRT follow-up observations of GRB071008
  32. Swift/UVOT upper limits for GRB 071117
  33. GRB071118: Swift XRT refined analysis
  34. GRB 071117: Gemini Optical Afterglow Discovery
  35. GRB 071118, Swift-BAT refined analysis
  36. GRB 071117: TAROT La Silla observatory optical observations
  37. GRB 071112B: Gemini Image Differencing
  38. GRB 071118: Swift detection of a burst
  39. GRB 071117: Gemini Observations
  40. GRB 071117: Las Campanas optical observations
  41. GRB 071117: Swift-XRT refined analysis
  42. GRB 071117, Swift-BAT refined analysis
  43. VLT FORS2 observations of short hard GRB071112B
  44. GRB 071117: Swift/XRT position
  45. GRB 071117: Initial Swift/UVOT observations
  46. GRB 071117: Swift detection of a bright burst
  47. Swift detection of MXB 0656-072
  48. VLA radio upper limit on GRB 071112C
  49. ATCA radio observations of short hard burst GRB 071112B
  50. GRB 071112C: Optical and NIR data observed with KANATA
  51. Correction to the Swift-BAT Transient Identification (trigger=296683)
  52. GRB 071112C: WSRT Radio Observations
  53. GRB071112C: Errata of MITSuME Ic band photometry
  54. GRB 071112C: optical observation
  55. GRB 071112C: optical observation
  56. GRB 071112C: emission lines and refined VLT redshift
  57. GRB 071112C MITSuME Akeno early optical observation
  58. GRB 071112C: Gemini Absorption Redshift
  59. GRB 071112B: 2nd epoch of Magellan i-band imaging
  60. GRB 071112C: SARA upper limit
  61. GRB 071112C : Second Epoch Lulin R-band observations
  62. GRB071112C MITSuME Okayama Optical Observation
  63. GRB 071112C: Swift-BAT refined analysis
  64. GRB 071112C: Swift/UVOT observations
  65. GRB 071112C: Swift XRT refined analysis
  66. GRB 071112C: Optical observations at Crni Vrh
  67. Swift UVOT upper limits of GRB071112B
  68. GRB 071112C: VLT redshift
  69. GRB 071112B: Magellan i-band imaging
  70. GRB 071112B: Gemini Optical Imaging (Correction)
  71. GRB 071112B: Gemini Optical Imaging
  72. GRB 071112B: Swift-XRT preliminary analysis
  73. GRB 071112B, Swift-BAT partial refined analysis of the SHB
  74. GRB071112C: NOT observations
  75. GRB 071112C: Palomar Pre-Imaging
  76. Swift-BAT trigger 296491 is not a GRB
  77. GRB 071112C : Lulin R-band observation
  78. GRB 071112C: RTT150 optical observations
  79. GRB 071112C: TAROT Calern observatory optical observations
  80. Swift XRT follow-up observations of GRB071028B
  81. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  82. GRB 071112C: Optical and NIR afterglows observed with KANATA
  83. GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
  84. GRB 071112B: ROTSE-III Rapid Optical Limits
  85. GRB 071112C: Swift detection of a burst with an optical counterpart
  86. GRB 071112B: Swift detection of a short hard burst
  87. GRB 071112: Swift detection of a possible burst
  88. GRB071109: Super-LOTIS observations
  89. VLA IInd observation of INTEGRAL burst GRB 071109
  90. Swift/UVOT initial analysis of GRB071109
  91. GRB 071109: further Swift-XRT analysis
  92. GRB 071109: TAROT Calern observatory optical observations
  93. No radio detection at Swift-XRT position
  94. GRB 071109: Swift-XRT possible X-ray counterpart
  95. VLA prompt radio detection of the INTEGRAL burst 071109
  96. GRB 071109: IBIS refined analysis
  97. GRB 071109: BOOTES-2 prompt optical observations
  98. GRB 071109: A long GRB detected by INTEGRAL
  99. GRB 071104: Swift-XRT Team Refined Analysis
  100. GRB 071104: Possible Swift UVOT Afterglow Candidate

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