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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 090807: Swift-XRT refined analysis
  2. GRB 090807, Swift-BAT refined analysis
  3. GRB 090807: Enhanced Swift-XRT position
  4. GRB 090807, RIMOTS optical upper limits
  5. GRB 090807: Swift detection of a burst
  6. Fermi Gamma-ray Burst Monitor trigger 271275771 is not a GRB
  7. GRB 090802B: Fermi GBM detection
  8. IPN Triangulation and Konus-Wind observaions of GRB090727B
  9. GRB 090802: Fermi GBM detection
  10. GRB 090726: optical observation
  11. Swift-BAT trigger 358760 is most likely not a GRB
  12. Swift trigger 358760 is probably a noise event
  13. GRB 090717A: Suzaku WAM observation of the prompt emission
  14. GRB 090709A : Quick look analysis of the Suzaku observation
  15. GRB 090728: Swift-BAT refined analysis
  16. GRB 090727: GRT Optical Observation
  17. GRB 090728: Swift XRT refined analysis
  18. GRB 090727: optical observations
  19. GRB 090726: GRT Optical Observation
  20. GRB 090727: Swift/UVOT Upper Limits
  21. GRB 090728: Swift/UVOT Upper Limits
  22. GRB 090728: Enhanced Swift-XRT position
  23. GRB 090727: I-band observations from 1.23m CAHA
  24. GRB 090728, RIMOTS optical upper limits
  25. GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
  26. GRB 090728: Swift detection of a burst
  27. GRB 090727: Swift-BAT refined analysis
  28. GRB 090727: Swift-XRT refined analysis
  29. GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
  30. GRB 090727: Enhanced Swift-XRT position
  31. GRB 090715B: Late-time Lick 3m observations
  32. GRB 090727: Liverpool Telescope possible OT candidate
  33. GRB 090727: Swift detection of a burst
  34. GRB090726: Swift/UVOT observations
  35. GRB 090726, Swift-BAT refined analysis
  36. GRB 090726: Afterglow candidate photometryfrom Crni Vrh
  37. GRB 090726: D50 optical observations
  38. GRB 090711: Fermi GBM detection
  39. GRB090726: 6-meter telescope redshift
  40. GRB 090726: Swift-XRT Team refined analysis
  41. GRB 090726: Enhanced Swift-XRT position
  42. GRB 090726: optical transient candidate
  43. GRB 090726: Swift/UVOT Finding Chart Observation
  44. GRB 090726: Swift-XRT position of probable counterpart
  45. GRB 090726: Swift detection of a burst
  46. Swift Trigger 358354 is not a GRB
  47. Konus-Wind and Konus-RF observations of GRB 090719
  48. Konus-RF and Konus-Wind observations of GRB 090718B
  49. Fermi Gamma-ray Burst Monitor triggers 269935914 through 270021937 are not GRBs
  50. Konus-Wind observations of bright hard GRB 090720B
  51. IPN Triangulation of bright GRB 090720B
  52. GRB 090720: Gemini-North Imaging and Optical Afterglow
  53. GRB 090720B: Fermi GBM detection
  54. Swift XRT and UVOT refned analysis of GRB 090720
  55. GRB 090709A: Swift XRT Timing Analysis
  56. GRB 090715B: VLA radio detection
  57. GRB 090720 Source found in ground processing of Swift-BAT data
  58. GRB 090717B: Fermi GBM detection
  59. GRB 090717: Fermi GBM detection
  60. GRB 090719: Fermi GBM detection
  61. GRB 090718B: Fermi GBM detection
  62. GRB 090718: Fermi GBM detection
  63. GRB 090720: Fermi GBM detection
  64. GRB 090715B: further NOT optical observations
  65. GRB 090715A: Suzaku WAM observation of the prompt emission
  66. GRB 090709A - CARMA mm Observations
  67. GRB 090715B: Lick observations
  68. GRB 090715A: VLA observations
  69. Konus-Wind observations of short/hard GRB 090715A
  70. GRB 090715B: MASTER optical limit
  71. GRB 090715A: Swift-BAT refined analysis
  72. Konus-Wind and Konus-RF observations of GRB 090715B
  73. GRB 090715B: Swift/UVOT followup observations
  74. GRB 090715B: break in the optical afterglow decay
  75. GRB 090715B: Enhanced Swift-XRT position
  76. GRB 090715B: Observation of the optical afterglow
  77. GRB 090715B: Swift XRT Refined Analysis
  78. GRB090715B: WHT redshift
  79. GRB 090715B: Swift-BAT refined analysis
  80. GRB 090715B: NOT optical observations
  81. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  82. Swift problem fixed
  83. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  84. GRB 090715A: ROTSE-III Optical Limits
  85. GRB 090715: Swift detection of a short hard burst
  86. Detection of GRB 090618 by RT-2 Experiment onboard the CORONAS-PHOTON Satellite
  87. Swift satellite anomaly
  88. GRB090713 optical limit by "Pi of the Sky"
  89. GRB 090712: Fermi GBM observation
  90. GRB 090713: Fermi GBM detection
  91. GRB 090712: Swift-BAT refined analysis
  92. GRB 090712: Swift detection of a burst
  93. GRB 090709A: Xinglong TNT optical upper limit
  94. VLA radio observations of GRB 090709A
  95. GRB 090621B: MTM-500 optical observations
  96. GRB 090709A: deep optical observation with the 10.4m GTC
  97. GRB090709A : WSRT Radio observation
  98. GRB 090709A: Suzaku WAM observation of the prompt emission
  99. GRB 090709A: Swift UVOT upper limits
  100. GRB 090709A: WHT LIRIS observations

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