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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"

19598 results found.

  1. GRB 130427B: Swift-BAT refined analysis
  2. GRB 130427A: Zadko observatory - Gingin optical observations
  3. GRB 130427B: Enhanced Swift-XRT position
  4. GRB 130427A: MAXI/GSC detection
  5. GRB 130427B: Faulkes Telescope North afterglow detection
  6. GRB 130427B: Swift detection of a burst with optical counterpart
  7. GRB 130427A: Continued P60 follow-up of an extremely bright optical afterglow
  8. GRB 130427A: PAIRITEL NIR Detections
  9. GRB 130427A: Faulkes Telescope North detection
  10. GRB 130427A: early optical observations
  11. GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
  12. GRB 130420A: Continued Skynet/GORT Observations/Detections
  13. GRB 130420B: CARMA and VLA radio observations
  14. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  15. GRB 130420A: Continued RATIR Optical and NIR Observations
  16. GRB 130420A: ROTSE-III data analysis
  17. GRB 130420A: Continued RATIR Optical and NIR Observations
  18. GRB 130420A: Early RAPTOR Simultaneous Multi-Color Observations
  19. GRB 130420B: Fermi GBM observation
  20. Swift Trigger 554135 is probably not a GRB or transient
  21. GRB 130420B: RATIR Optical and NIR Observations
  22. GRB 130420B: Swift-XRT refined Analysis
  23. GRB 130420A: Fermi GBM observation
  24. GRB 130420A: ISON-NM optical observations
  25. Skynet/GORT observations of GRB130420A
  26. GRB 130420B: Swift/UVOT Upper Limits
  27. GRB 130420A: Swift/UVOT Detection
  28. GRB 130420A: Swift-XRT refined Analysis
  29. GRB 130420B: Enhanced Swift-XRT position
  30. GRB 130420B, Swift-BAT refined analysis
  31. GRB 130420A, Swift-BAT refined analysis
  32. Konus-Wind observation of GRB 130418A
  33. GRB 130420A: Enhanced Swift-XRT position
  34. GRB 130420B: MASTER-Net optical observations
  35. GRB 130420B: Swift detection of a burst
  36. GRB 130420A: RATIR Optical and NIR Observations
  37. GRB 130420A: PAIRITEL NIR detections
  38. GRB 130420A: ROTSE-III Detection of Optical Counterpart
  39. GRB 130420A: Swift detection of a burst with an optical counterpart
  40. GRB 130420A: Faulkes Telescope North candidate
  41. GRB 130418A: Swift-XRT refined Analysis
  42. Swift Trigger 553930 is not an astrophysical source
  43. GRB 130419A, Swift-BAT refined analysis
  44. GRB 130327B: Swift/XRT source is not the afterglow
  45. GRB 130419B (Swift trigger Trigger 553930): MASTER-Net optical observations
  46. Trigger 553930: Swift detection of a possible flare from HR 5110
  47. GRB 130418A, Swift-BAT refined analysis
  48. GRB 130419A: Swift detection of a burst
  49. GRB 130418A: RATIR Optical and NIR Observations
  50. GRB 130418A: GROND detection of the optical-NIR afterglow
  51. GRB 130418A: Swift/UVOT Detection and request for continuing coverage
  52. GRB 130418A: Enhanced Swift-XRT position
  53. GRB 130418A: TAROT Calern and TAROT la Silla observatory optical observations
  54. GRB 130418A: Bassano Bresciano Observatory optical observations
  55. GRB 130418A: Swift detection of a burst with an optical counterpart
  56. GRB 130408a: Skynet Optical Observations
  57. GRB 130408A, Swift-BAT refined analysis
  58. GRB 130408A: Zadko observatory - Gingin optical observations
  59. GRB 130407A: Swift-XRT observations
  60. GRB130408A: Swift/UVOT followup observations
  61. GRB 130408A: Swift-XRT refined Analysis
  62. Konus-Wind observation of GRB 130408A
  63. GRB 130408A: Enhanced Swift-XRT position
  64. GRB 130408A: GROND detection of the afterglow
  65. GRB 130408A: Swift/UVOT Detection of the Optical Afterglow
  66. GRB 130408A: Liverpool Telescope Optical candidate detection
  67. GRB 130408A: Swift detection of a burst
  68. GRB 130407A Tiled Swift observations
  69. GRB 130211A: Retraction of afterglow candidate
  70. GRB 130327B: Suzaku WAM observation of the prompt emission
  71. Swift detection of IGR J18245-2452
  72. IPN Triangulation of GRB 130320B (very long/bright)
  73. Swift/XRT observation of GRB 130327B
  74. GRB 130306A: Confirmation of the X-ray Afterglow
  75. Swift Trigger 552142 is a noise event
  76. GRB 130327B: Fermi-LAT detection of a burst
  77. Swift Trigger 552142: a possible GRB
  78. GRB 130327A: Swift-BAT refined analysis
  79. GRB 130327A: Swift-XRT refined Analysis
  80. GRB 130327A: Swift/UVOT Upper Limits
  81. GRB 130327A: ISON-NM optical upper limit
  82. GRB 130325A Tiled Swift observations
  83. GRB 130327A: Enhanced Swift-XRT position
  84. GRB 130327A: PAIRITEL NIR Afterglow Candidate
  85. GRB 130325A: Fermi LAT detection
  86. GRB 130327A: Swift detection of a burst
  87. report: GRB 130315A: Zadko observatory - Gingin optical observations
  88. GRB 130315A: GROND afterglow candidate
  89. GRB 130305A: optical upper limit in Mondy observatory
  90. GRB 130315A: Swift/UVOT Upper Limits
  91. GRB 130313A: optical upper limit in CrAO
  92. GRB 130313A: optical upper limit in Mondy observatory
  93. GRB 130315A: SALT optical observations
  94. GRB 130315A: Swift-XRT refined Analysis
  95. Swift XRT observations of GRB 130310A
  96. GRB 130315A, Swift-BAT refined analysis
  97. GRB 130313A: Swift/UVOT Upper Limits
  98. GRB 130305A: PTF P48 optical upper limits
  99. GRB130315A BOOTES-3 optical limit
  100. GRB 130315A: Swift detection of a burst

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