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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"

26264 results found.

  1. GRB 090728A: Faulkes Telescope North Optical Afterglow Candidate
  2. GRB 090728: Swift detection of a burst
  3. GRB 090727: Swift-BAT refined analysis
  4. GRB 090727: Swift-XRT refined analysis
  5. GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
  6. GRB 090727: Liverpool Telescope possible OT candidate
  7. GRB 090727: Swift detection of a burst
  8. GRB090726: Swift/UVOT observations
  9. GRB 090726, Swift-BAT refined analysis
  10. GRB 090726: D50 optical observations
  11. GRB 090711: Fermi GBM detection
  12. GRB090726: 6-meter telescope redshift
  13. GRB 090726: Swift-XRT Team refined analysis
  14. GRB 090726: optical transient candidate
  15. GRB 090726: Swift/UVOT Finding Chart Observation
  16. GRB 090726: Swift-XRT position of probable counterpart
  17. GRB 090726: Swift detection of a burst
  18. Swift Trigger 358354 is not a GRB
  19. Konus-Wind and Konus-RF observations of GRB 090719
  20. Konus-RF and Konus-Wind observations of GRB 090718B
  21. Fermi Gamma-ray Burst Monitor triggers 269935914 through 270021937 are not GRBs
  22. Konus-Wind observations of bright hard GRB 090720B
  23. IPN Triangulation of bright GRB 090720B
  24. GRB 090720: Gemini-North Imaging and Optical Afterglow
  25. GRB 090720B: Fermi GBM detection
  26. GRB 090709A: Swift XRT Timing Analysis
  27. GRB 090720 Source found in ground processing of Swift-BAT data
  28. GRB 090717B: Fermi GBM detection
  29. GRB 090717: Fermi GBM detection
  30. GRB 090719: Fermi GBM detection
  31. GRB 090718B: Fermi GBM detection
  32. GRB 090718: Fermi GBM detection
  33. GRB 090720: Fermi GBM detection
  34. GRB 090715A: Suzaku WAM observation of the prompt emission
  35. GRB 090709A - CARMA mm Observations
  36. Konus-Wind observations of short/hard GRB 090715A
  37. GRB 090715B: MASTER optical limit
  38. GRB 090715A: Swift-BAT refined analysis
  39. GRB 090715B: Swift/UVOT followup observations
  40. GRB 090715B: break in the optical afterglow decay
  41. GRB 090715B: Swift XRT Refined Analysis
  42. GRB 090715B: Swift-BAT refined analysis
  43. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  44. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  45. GRB 090715A: ROTSE-III Optical Limits
  46. GRB 090715: Swift detection of a short hard burst
  47. GRB090713 optical limit by "Pi of the Sky"
  48. GRB 090712: Fermi GBM observation
  49. GRB 090713: Fermi GBM detection
  50. GRB 090712: Swift-BAT refined analysis
  51. GRB 090712: Swift detection of a burst
  52. GRB 090709A: Xinglong TNT optical upper limit
  53. GRB 090709A: Suzaku WAM observation of the prompt emission
  54. GRB 090709A: Swift UVOT upper limits
  55. GRB 090709B: Fermi GBM detection
  56. GRB 090709A: P60 Observations
  57. GRB 090709A: NOT optical observations
  58. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  59. GRB 090709A: Swift XRT Refined Analysis
  60. GRB 090709B, Swift-BAT refined analysis
  61. GRB 090709A: Swift-BAT refined analysis
  62. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  63. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  64. GRB 090709A, RIMOTS optical upper limits
  65. GRB 090709B: Swift detection of a burst
  66. GRB 090708 : Fermi GBM detection
  67. GRB 090626: Suzaku WAM observation of the prompt emission
  68. GRB 090709: PAIRITEL NIR Upper Limits
  69. GRB 090704: Fermi GBM observation
  70. GRB 090709: ROTSE-III Optical Limits
  71. GRB 090709: Swift detection of a bright burst
  72. GRB 090708: Early RAPTOR Optical Limits
  73. GRB 090708, Swift-BAT refined analysis
  74. GRB 090708: ROTSE-III Optical Limits
  75. GRB 090708: Swift detection of a burst
  76. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  77. GRB 090706: Fermi GBM detection
  78. Swift-BAT trigger 356516 is not a GRB
  79. Possible GRB090705: Swift-XRT observations
  80. GRB 090705: PAIRITEL NIR Observations
  81. GRB 090705: Swift detection of a possible burst
  82. GRB 090703: Fermi GBM detection
  83. GRB 090702: UVOT upper limits
  84. XRF 090702: Swift-XRT afterglow position
  85. GRB 090701: Fermi GBM detection
  86. GRB 090628: Swift XRT refined analysis
  87. GRB 090630: Fermi GBM detection
  88. GRB 090628: Swift/UVOT Upper Limits
  89. Konus-Wind observation of GRB 090626
  90. GRB080628: SAO RAS optical observations
  91. GRB 090628: Swift-BAT refined analysis
  92. GRB 090628: GROND upper limits
  93. GRB 090626: IPN localization
  94. GRB 090628: Swift/UVOT Finding Chart Observation
  95. GRB 090628: Swift XRT position
  96. GRB 090628: Swift detection of a burst
  97. Fermi LAT observations of GRB 090626
  98. GRB 090625B: Fermi GBM observation
  99. GRB 090625B: Swift-XRT refined analysis
  100. GRB 090626: Fermi GBM detection

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