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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 150817A: AAO optical observations
  2. GRB 150818A: Enhanced Swift-XRT position
  3. GRB 150817A: LCOGT observations
  4. GRB 150818A: Swift-BAT refined analysis
  5. GRB 150817A: Continued RATIR Optical Observations - Afterglow Confirmation
  6. GRB 150818A: Swift/UVOT candidate afterglow
  7. GRB 150818A: Planned XMM-Newton observation
  8. GRB 150817A: P60 Observations
  9. GRB 150818A: Swift detection of a burst
  10. MASTER OT inside bright ESO240-010 galaxy detection during FERMI trigger GRB150816.83 inspection
  11. GRB 150817A: Swift/UVOT Upper Limits
  12. GRB 150817A: Fermi GBM observation
  13. GRB 150817A: Swift-BAT refined analysis
  14. GRB 150817A: Swift-XRT refined Analysis
  15. GRB 150817A: Enhanced Swift-XRT position
  16. GRB 150817A: Continued RATIR Observations, Revised Candidate
  17. GRB 150817A: RATIR Optical Afterglow Candidate
  18. GRB 150817A: Swift detection of a burst
  19. Fermi GBM Trigger 150815694 is not a GRB
  20. GRB 150811A: Continued RATIR Observations
  21. GRB 150811A: Continued RATIR Observations
  22. GBM Trigger 150813665 is not a GRB
  23. Swift Trigger 652046 is a particle shower event
  24. Konus-Wind observation of GRB 150811B
  25. Swift Trigger 652046 is probably not a GRB
  26. GRB 150811A: KAIT Refined Analysis
  27. GRB 150811A: VLA Detection
  28. IPN Triangulation of GRB 150811B
  29. GRB 150811A: Continued RATIR Observations
  30. GRB 150811A: Swift/UVOT further observations
  31. GRB 150811B: Fermi GBM detection
  32. GRB 150811A: Swift-BAT refined analysis
  33. GRB 150811A: SAO RAS optical observations
  34. GRB 150811A: Swift-XRT refined Analysis
  35. GRB 150810A: Fermi GBM detection
  36. GRB 150811A: P60 Observations
  37. GRB 150811A: Enhanced Swift-XRT position
  38. GRB 150811A: LCOGT-McDonald afterglow detection
  39. GRB 150811A: Swift/UVOT Detection
  40. GRB 150811A: KAIT optical candidate
  41. GRB 150811A: RATIR Optical Afterglow Detection
  42. GRB 150811A: Swift detection of a burst
  43. Fermi GBM GRB Trigger 460608875: iPTF P48 Observations
  44. Fermi GBM trigger 150807969 is not a GRB
  45. Fermi GBM trigger 150806450 is not a GRB
  46. GRB 150728A: TNG optical observations
  47. Fermi GBM trigger 150805556 is not a GRB
  48. GRB 150727A: IRSF NIR observation
  49. GRB 150801A: Swift-XRT observations
  50. GRB 150801B: Swift/UVOT Upper Limits
  51. GRB 150801B: Swift-BAT refined analysis
  52. GRB 150801B: Swift-XRT refined Analysis
  53. GRB 150801B: Enhanced Swift-XRT position
  54. Fermi GBM triggers 150730606 150731173 and 150801590 are not due to GRBs
  55. Fermi GBM GRB Trigger 458852670: iPTF P48 Observations
  56. GRB 150721A (Fermi GBM Trigger 459150552): iPTF P48 Observations
  57. GRB 150801B: Swift detection of a burst
  58. GRB 150801A: Tiled Swift observations
  59. GRB 150801A: MAXI/GSC detection
  60. GRB 150724B: Swift-XRT afterglow detection
  61. GRB 150424A: HST imaging
  62. GRB150724B: Retraction of the uvot detection
  63. GRB 150728A: Continued RATIR Optical Observations
  64. GRB 150728A: TSHAO optical observations
  65. GRB 150728A: RATIR Optical Observations
  66. GRB 150727A: Continued RATIR Optical Observations - Fading
  67. GRB 150728A: AAO optical observations
  68. GRB 150728A: Swift-XRT refined Analysis
  69. GRB 150728A: Swift/UVOT Upper Limits
  70. GRB 150728A: Swift-BAT refined analysis
  71. GRB 150728A: FTN observations
  72. GRB 150727A: RATIR Optical Observations
  73. GRB 150728A: Enhanced Swift-XRT position
  74. GRB 150728A: Swift detection of a GRB
  75. GRB 150727A: Swift-BAT refined analysis
  76. GRB 150727A: Watcher optical upper limit
  77. GRB 150727A: Swift/UVOT Detection
  78. GRB 150727A: LCOGT-Cerro Tololo observations
  79. GRB 150727A: Swift-XRT refined Analysis
  80. GRB 150727A: Fermi GBM detection
  81. GRB 150727A: VLT/X-shooter redshift
  82. GRB 150727A: Enhanced Swift-XRT position
  83. GRB 150724B: Continued RATIR Optical Observations
  84. GRB 150724B: MASTER upper limit
  85. GRB 150727A: Swift detection of a burst with an optical counterpart
  86. GRB 150724B: Swift/UVOT Detection
  87. Konus-Wind observation of GRB 150724B
  88. Konus-Wind observation of GRB 150725A
  89. GRB 150724B: RATIR Optical Observations
  90. Swift Trigger 650408 is not a burst
  91. Swift 650221/IGR J00291+5934: Liverpool Telescope observations
  92. GRB 150724B: Swift-XRT observations
  93. GRB 150724B: Swift ToO observations
  94. IGR J00291+5934, Swift-BAT refined analysis
  95. GRB 150724B: Fermi GBM detection
  96. GRB 150724B: Fermi-LAT detection
  97. Swift Trigger 650221 / IGR J00291+5934: MASTER-IAC OT observations
  98. Fermi GBM trigger 150725291 is not a GRB
  99. GRB 150725A: MAXI/GSC detection
  100. Trigger 650221: Swift detection of a IGR J00291+5934

Advanced

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