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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. Swift trigger 346250 is probably not a burst
  2. GRB090310: Fermi GBM detection
  3. GRB 090205: Zadko Telescope late-time observations
  4. GRB 090309A: GROND upper limits
  5. GRB 090307A: TAROT Calern observatory optical observations
  6. GRB 090309: Swift/UVOT Upper Limits
  7. GRB090305B: Fermi GBM detection
  8. GRB 090309B: Fermi GBM detection
  9. GRB 090309: Swift-XRT refined analysis
  10. GRB 090309: Enhanced Swift-XRT position
  11. GRB 090306B: INTEGRAL SPI-ACS light curve
  12. GRB 090309, Swift-BAT refined analysis
  13. GRB 090308: GROND observations
  14. GRB 090308: Gemini GMOS Observations
  15. GRB 090309: Swift detection of a burst
  16. GRB 090308B: Fermi GBM detection
  17. GRB 090308: Swift/UVOT Upper Limits
  18. GRB 090307B: Fermi GBM detection
  19. GRB 090306C: Fermi GBM detection
  20. GRB 090307: GROND Upper Limits
  21. GRB 090306B: GROND Upper Limits
  22. GRB 090305C: Suzaku WAM observation of the prompt emission
  23. GRB 090308: Swift-XRT refined analysis
  24. Radio observation of GRB 090201 with ATCA
  25. Radio observation of GRB 090117 with ATCA
  26. Radio observation of GRB 081226b with ATCA
  27. Radio observation of GRB 081226a with ATCA
  28. Radio observation of GRB 081007 with ATCA
  29. ATCA observation of SGR J1550-5418
  30. GRB 090308: Swift-BAT refined analysis
  31. GRB 090308: Swift detection of a burst
  32. GRB 090306B: Possible XRT afterglow
  33. GRB 090307: Swift-XRT afterglow confirmation and analysis
  34. GRB 090307: Swift-BAT refined analysis of trigger 345551
  35. GRB 090306B: Burst detection from Swift-BAT slew data
  36. Swift Trigger 345551 is probably not a GRB
  37. Swift-BAT trigger 345396 is not a GRB
  38. IPN localization of short GRB 090305C
  39. Fermi GBM trigger 090305784 is not a GRB
  40. GRB 090306: Swift detection of a possible burst
  41. GRB 090305: Swift/UVOT Upper Limits
  42. GRB 090305: Swift-XRT refined analysis
  43. GRB 090305, Swift-BAT refined analysis
  44. GRB 090227A: Suzaku WAM observation of the prompt emission
  45. GRB 090305: Magellan confirmation of the optical afterglow
  46. GRB090305: GMOS-S Candidate Optical Afterglow
  47. GRB 090305: Swift detection of a short burst
  48. GRB 090303: Fermi GBM detection
  49. GRB 090304: Fermi GBM detection
  50. GRB 090301A: Suzaku WAM observation of the prompt emission
  51. Konus-RF catches first GRB and SGR bursts
  52. GRB 090228B: Fermi GBM detection
  53. Konus-Wind observation of bright short GRB 090227B
  54. IPN localization of short bright GRB 090227B
  55. Konus-Wind observation of GRB 090301A
  56. GRB 090301A: Swift-BAT refined analysis
  57. GRB 090301B: Fermi GBM detection
  58. GRB 090227B: Fermi GBM detection
  59. GRB 090301: Swift detection of a burst
  60. Swift_BAT_Lightcurve Notice for Trigger Number 344565 is not valid
  61. GRB 090228: Fermi GBM detection
  62. GRB 090227: Fermi GBM detection
  63. GRB 090206: Fermi GBM detection
  64. SGR J1550-5418
  65. GRB 081211B: Nearby cluster
  66. Ongoing activity of AXP/SGR 1E1547.0-5408
  67. GRB 090222: Fermi GBM detection
  68. GRB 090219: Fermi GBM detection
  69. Swift Restored
  70. Swift Trigger 343319 is not a GRB
  71. GRB 090217: Suzaku WAM observation of the prompt emission
  72. GRB090217: XRT analysis
  73. Konus-Wind observation of GRB 090217
  74. IPN localization of GRB 090217
  75. GRB 090213: Fermi GBM detection
  76. GRB090217: Fermi-LAT Detection
  77. GRB 090217: Fermi GBM detection
  78. SGR activity seen by BAT during ICSP Ionospheric Events
  79. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  80. GRB 090207 - Fermi GBM Observations
  81. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  82. GRB 090129: Fermi GBM detection
  83. VLA radio upper limit on GRB 090205
  84. GRB 090205: VLT optical decay
  85. Fermi Gamma-ray Burst Monitor trigger 255541748 cannot be classified
  86. GRB 090205: Swift/UVOT Upper Limits
  87. GRB 090205: VLT refined redshift
  88. GRB 090205: Swift-XRT refined analysis
  89. GRB 090205: Swift burst of interest
  90. GRB 090205: VLT spectroscopic redshift
  91. GRB 090205: GROND observations and photometric redshift estimate
  92. GRB 090205: VLT candidate afterglow
  93. GRB 090205: Swift-BAT refined analysis
  94. GRB 090205: Enhanced Swift-XRT position
  95. GRB 090205: Swift detection of a burst
  96. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  97. GRB 090131: Suzaku WAM observation of the prompt emission
  98. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  99. GRB 090126A: Swift-XRT afterglow confirmation
  100. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB

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