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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"

6792 results found.

  1. GRB 120630A: Swift-BAT/-XRT/-UVOT refined analysis
  2. GRB120624B: Chandra observations and afterglow detection
  3. GRB 120624B Further Swift-XRT analysis
  4. Watcher follow-up observations of IGR J17062-6143 (Swift trigger 525148)
  5. GRB 120624B: Swift-XRT observations
  6. GRB 120624B: optical observations
  7. Konus-Wind observation of GRB 120624B
  8. GRB 120624A: Fermi GBM observation
  9. GRB 120624B: Fermi-LAT Detection
  10. GRB 120624B: Fermi GBM detection
  11. Konus-Wind observation of GRB 120617A
  12. Konus-Wind observation of GRB 120602A
  13. GRB 120612A: Swift-XRT refined Analysis
  14. GRB 120521B: Fermi GBM observation
  15. GRB 120521C: Swift-XRT refined Analysis
  16. GRB 120521B: GROND Upper limits
  17. GRB 120521A: Swift-XRT refined Analysis
  18. GRB 120521C: PAIRITEL NIR Upper Limits
  19. GRB 120521B: Swift-XRT refined Analysis
  20. GRB 120514A: Swift-XRT refined Analysis
  21. GRB 120510A: Swift XRT and UVOT observations
  22. Konus-Wind observation of GRB 120427A
  23. Konus-Wind observation of GRB 120426A
  24. Swift Trigger 520928 is probably not a burst
  25. GRB 120422A: VLT/X-shooter spectroscopy of the GRB counterpart
  26. GRB 120422A: NOT optical observations
  27. GRB 120422A: Swift-XRT refined Analysis
  28. GRB 120419A: Swift-XRT and UVOT observations
  29. GRB 120403B: Swift-XRT refined Analysis
  30. GRB 120404A: Swift-XRT refined Analysis
  31. GRB 120403B: Fermi GBM Observation
  32. GRB 120403B: AAT nIR observations
  33. GRB 120402B: Fermi GBM detection
  34. GRB 120401A: Swift-XRT refined Analysis
  35. The Swift-XRT source associated with trigger 518853 is a cosmic ray
  36. GRB 120328B: Fermi GBM detection
  37. GRB 120328A: Swift-XRT refined Analysis
  38. GRB 120326A: Fermi GBM Observation
  39. GRB 120326A: PAIRITEL NIR Observations
  40. GRB 120327A: Swift-XRT refined Analysis
  41. GRB 120327A: CQUEAN grizY Observation
  42. GRB 120326A: LOAO R-band Observations
  43. GRB 120326A: optical observation of GMG
  44. GRB 120326A: CQUEAN grizY Observation
  45. GRB 120326A: Swift-XRT refined Analysis
  46. Konus-Wind observation of GRB 120323A
  47. GRB 120324A: Swift-XRT refined Analysis
  48. GRB 120323A: Fermi GBM detection
  49. GRB 120316A: Fermi-GBM and Fermi-LAT Observations
  50. GRB 120320A , optical observations
  51. GRB 120320A: Swift-XRT refined Analysis
  52. GRB 120302A: Swift XRT refined analysis
  53. GRB 120311B: Optical follow-up
  54. GRB 120312A: NOT observations
  55. GRB 120312A: Swift-XRT refined Analysis
  56. GRB 120311B: Swift-XRT refined Analysis
  57. GRB 120311A: Swift-XRT refined Analysis
  58. GRB 120308A: RTT150 optical observations
  59. GRB 120302A: RTT150 optical observations
  60. GRB 120308A: Further PAIRITEL NIR Observations
  61. GRB 120308A: Swift-XRT refined Analysis
  62. GRB 120308A: PAIRITEL NIR observations
  63. GRB 120302A: Fermi GBM Observation
  64. GRB 120305A: Swift-XRT refined Analysis
  65. GRB 111222A: Swift observation on 2012 February 06/07
  66. GRB 120226A: Fermi-GBM and Fermi-LAT detections; LAT position retraction
  67. GRB 120226A: Fermi-LAT detection of a burst
  68. GRB 120224A: Swift-XRT refined Analysis
  69. GRB 120219A: Swift-XRT refined Analysis
  70. GRB 120215A: Swift-XRT refined Analysis
  71. GRB 120213A: Swift-XRT refined Analysis
  72. GRB 120212A: Fermi GBM observation
  73. GRB 120212A: Swift-XRT refined Analysis
  74. GRB 120212A: Errata of subject in GCNC 12936
  75. GRB 120211A: MITSuME Okayama Ks-band Observation
  76. GRB 120211A, optical observations
  77. GRB 120211A: Swift-XRT refined Analysis
  78. GRB 120211A: MITSuME Okayama Ks-band upper limit
  79. GRB 120211A: Swift detection of a burst
  80. GRB 120202A: Swift/XRT and UVOT observations
  81. GRB 120119A : LOAO Optical Observations
  82. GRB 120121A: Swift-XRT refined Analysis
  83. GRB 120119A: Swift-XRT refined Analysis
  84. GRB 120119A: Fermi GBM observation
  85. GRB 120118B: Swift-XRT refined Analysis
  86. GRB 120119A: PAIRITEL NIR Detection
  87. GRB 120118B: NOT observations
  88. GRB 120116A: Swift-XRT refined Analysis
  89. GRB 120116A: NOT observations
  90. GRB 120107A: Fermi GBM observation
  91. GRB 120106A: MITSuME Okayama Ks-band upper limit
  92. GRB 120106A: Swift-XRT refined Analysis
  93. GRB 111222A: Fermi GBM observations
  94. GRB 111222A: Second Swift observation
  95. GRB 120102A: Fermi GBM observation
  96. GRB 120102A: Swift-XRT refined Analysis
  97. GRB 111228A, optical observations
  98. GRB 111228A: correction for GCN 12787
  99. GRB 111228A: Optical and NIR observations with Kanata telescope
  100. GRB 111229A: Swift/UVOT Detection

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Download all Circulars as a .tar.gz archive (updated once a day):
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