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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 090323: Possible XRT Counterpart
  2. IPN triangulation of GRB090323
  3. GRB 090320C: Fermi GBM Detection
  4. Fermi GBM and LAT detections of GRB 090323
  5. GRB 090320B: Fermi GBM detection.
  6. GRB 090319: Fermi GBM detection
  7. GRB 090320A: Fermi GBM detection
  8. Further 15GHz observations of GRB090313
  9. GRB 090313: WSRT Radio Detection
  10. X-shooter observations of GRB 090313
  11. A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
  12. GRB 090315: Suzaku WAM observation of the prompt emission
  13. GRB 090313: VLT spectroscopy
  14. GRB090313: radio detection with the VLA
  15. Konus-Wind observation of GRB 090315
  16. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  17. GRB 090313, SMARTS optical/IR observations
  18. Further radio observation of GRB 090313
  19. Further Swift/UVOT observations of GRB 090313
  20. GRB 090313: detection with CARMA in 3mm band
  21. GRB090305B: MASTER-net prompt optical short burst observations
  22. Radio detection of GRB090313
  23. GRB 090313: MITSuME Okayama observation
  24. GRB 090313: Additional Gemini-S photometry
  25. GRB 090313: WSRT Radio Observations
  26. GRB 090313: Light curve steepening
  27. GRB 090313: TAROT La Silla observatory optical detection
  28. GRB 090313: Gemini-S photometry
  29. GRB 090313: Zadko Telescope observations
  30. GRB 090313 - PAIRITEL NIR detections
  31. GRB 090313: Gemini-S redshift
  32. GRB 090313 optical observations
  33. GRB 090313: Ongoing plateau phase
  34. GRB 090313: Swift-XRT refined analysis
  35. GRB 090313: Swift/UVOT upper limits
  36. GRB 090313: Faulkes Telescope North observations
  37. GRB 090313: Sustained optical brightness (correction)
  38. GRB 090306B: Confirmation of the X-ray afterglow
  39. GRB 090313: Swift-BAT refined analysis
  40. GRB 090313: Sustained optical brightness
  41. GRB 090313: SDSS object underlying the optical afterglow position
  42. GRB 090313, GROND observations
  43. GRB 090309, Swift-BAT lag analysis
  44. GRB 090313: Swift detection of a burst
  45. GRB 090313: Swift detection of a burst
  46. GRB 090313 OA candidate
  47. Swift trigger 346250 is probably not a burst
  48. GRB090310: Fermi GBM detection
  49. GRB 090205: Zadko Telescope late-time observations
  50. GRB 090309A: GROND upper limits
  51. GRB 090307A: TAROT Calern observatory optical observations
  52. GRB 090309: Swift/UVOT Upper Limits
  53. GRB090305B: Fermi GBM detection
  54. GRB 090309B: Fermi GBM detection
  55. GRB 090309: Swift-XRT refined analysis
  56. GRB 090309: Enhanced Swift-XRT position
  57. GRB 090306B: INTEGRAL SPI-ACS light curve
  58. GRB 090309, Swift-BAT refined analysis
  59. GRB 090308: GROND observations
  60. GRB 090308: Gemini GMOS Observations
  61. GRB 090309: Swift detection of a burst
  62. GRB 090308B: Fermi GBM detection
  63. GRB 090308: Swift/UVOT Upper Limits
  64. GRB 090307B: Fermi GBM detection
  65. GRB 090306C: Fermi GBM detection
  66. GRB 090307: GROND Upper Limits
  67. GRB 090306B: GROND Upper Limits
  68. GRB 090305C: Suzaku WAM observation of the prompt emission
  69. GRB 090308: Swift-XRT refined analysis
  70. Radio observation of GRB 090201 with ATCA
  71. Radio observation of GRB 090117 with ATCA
  72. Radio observation of GRB 081226b with ATCA
  73. Radio observation of GRB 081226a with ATCA
  74. Radio observation of GRB 081007 with ATCA
  75. ATCA observation of SGR J1550-5418
  76. GRB 090308: Swift-BAT refined analysis
  77. GRB 090308: Swift detection of a burst
  78. GRB 090306B: Possible XRT afterglow
  79. GRB 090307: Swift-XRT afterglow confirmation and analysis
  80. GRB 090307: Swift-BAT refined analysis of trigger 345551
  81. GRB 090306B: Burst detection from Swift-BAT slew data
  82. Swift Trigger 345551 is probably not a GRB
  83. Swift-BAT trigger 345396 is not a GRB
  84. IPN localization of short GRB 090305C
  85. Fermi GBM trigger 090305784 is not a GRB
  86. GRB 090306: Swift detection of a possible burst
  87. GRB 090305: Swift/UVOT Upper Limits
  88. GRB 090305: Swift-XRT refined analysis
  89. GRB 090305, Swift-BAT refined analysis
  90. GRB 090227A: Suzaku WAM observation of the prompt emission
  91. GRB 090305: Magellan confirmation of the optical afterglow
  92. GRB090305: GMOS-S Candidate Optical Afterglow
  93. GRB 090305: Swift detection of a short burst
  94. GRB 090303: Fermi GBM detection
  95. GRB 090304: Fermi GBM detection
  96. GRB 090301A: Suzaku WAM observation of the prompt emission
  97. Konus-RF catches first GRB and SGR bursts
  98. GRB 090228B: Fermi GBM detection
  99. Konus-Wind observation of bright short GRB 090227B
  100. IPN localization of short bright GRB 090227B

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