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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"

43608 results found.

  1. GRB 130418A: WSRT radio observation
  2. Swift Trigger 554135 is probably not a GRB or transient
  3. GRB 130420B: RATIR Optical and NIR Observations
  4. GRB 130420A: Continued RATIR Optical and NIR Observations
  5. GRB 130420B: Swift-XRT refined Analysis
  6. GRB 130420A: Fermi GBM observation
  7. GRB 130420A: ISON-NM optical observations
  8. Skynet/GORT observations of GRB130420A
  9. GRB 130420B: Weihai optical upper limit
  10. GRB 130420A: Swift/UVOT Detection
  11. GRB130420B: GMG optical upper limit
  12. GRB 130420A: Swift-XRT refined Analysis
  13. GRB 130420B: Enhanced Swift-XRT position
  14. GRB 130420B, Swift-BAT refined analysis
  15. GRB 130420A, Swift-BAT refined analysis
  16. GRB 130420A: GMG optical observation
  17. Konus-Wind observation of GRB 130418A
  18. GRB 130420A: Enhanced Swift-XRT position
  19. GRB130420A : Xinglong TNT optical upper limit
  20. GRB 130420B: Faulkes Telescope North observations
  21. GRB 130420B: MASTER-Net optical observations
  22. GRB 130420B: Swift detection of a burst
  23. GRB 130420A: T21 optical observations
  24. GRB 130420A: RATIR Optical and NIR Observations
  25. GRB 130420A: PAIRITEL NIR detections
  26. GRB 130420A: ROTSE-III Detection of Optical Counterpart
  27. GRB 130420A: Swift detection of a burst with an optical counterpart
  28. GRB 130420A: Faulkes Telescope North candidate
  29. GRB 130418A: Continued RATIR Optical and NIR Observations
  30. GRB 130418A: Swift-XRT refined Analysis
  31. Swift Trigger 553930 is not an astrophysical source
  32. GRB 130418A: SMARTS optical/IR afterglow observations
  33. GRB 130418A: Submm observations from SMA
  34. GRB 130419A, Swift-BAT refined analysis
  35. GRB 130327B: Swift/XRT source is not the afterglow
  36. GRB 130419B (Swift trigger Trigger 553930): MASTER-Net optical observations
  37. Trigger 553930: Swift detection of a possible flare from HR 5110
  38. GRB 130418A: T21 optical observation
  39. GRB 130418A: T18 and T21 optical observations
  40. GRB 130418A: LOAO Observation
  41. GRB 130418A, Swift-BAT refined analysis
  42. GRB 130419A: Swift detection of a burst
  43. GRB130418A: VLT/X-shooter redshift confirmation
  44. GRB 130418A: RATIR Optical and NIR Observations
  45. GRB 130418A: CARMA 3mm detection
  46. GRB 130418A: GROND detection of the optical-NIR afterglow
  47. GRB130418A: OSN 1.5m fading afterglow detection
  48. GRB 130418A: Swift/UVOT Detection and request for continuing coverage
  49. GRB 130418A: Enhanced Swift-XRT position
  50. GRB 130418A: TAROT Calern and TAROT la Silla observatory optical observations
  51. GRB 130418A: TNG optical observations
  52. GRB 130418A: Redshift from 10.4m GTC
  53. GRB 130418A: Bassano Bresciano Observatory optical observations
  54. GRB 130418A: 1.23m I-band observations
  55. GRB 130418A: Swift detection of a burst with an optical counterpart
  56. GRB 130408A: Suzaku WAM observation of the prompt emission
  57. GRB 130408a: Skynet Optical Observations
  58. GRB 130408A: SMARTS optical/IR afterglow observations
  59. GRB 130408A, Swift-BAT refined analysis
  60. GRB 130408A: Zadko observatory - Gingin optical observations
  61. GRB 130407A: Swift-XRT observations
  62. GRB130408A: Swift/UVOT followup observations
  63. GRB 130408A: Swift-XRT refined Analysis
  64. Konus-Wind observation of GRB 130408A
  65. GRB 130408A: Enhanced Swift-XRT position
  66. GRB 130408A - Gemini-S/GMOS redshift determination
  67. GRB 130408A - VLT/X-shooter redshift determination
  68. GRB 130408A: GROND detection of the afterglow
  69. GRB 130408A: Swift/UVOT Detection of the Optical Afterglow
  70. GRB 130408A: Liverpool Telescope Optical candidate detection
  71. GRB 130408A: Swift detection of a burst
  72. GRB 130407A Tiled Swift observations
  73. GRB 130407A: MAXI/GSC detection
  74. GRB 130211A: Retraction of afterglow candidate
  75. GRB 130327B: Suzaku WAM observation of the prompt emission
  76. Konus-Wind observation of GRB 130320B
  77. Swift detection of IGR J18245-2452
  78. IPN Triangulation of GRB 130320B (very long/bright)
  79. Swift/XRT observation of GRB 130327B
  80. GRB 130327A: RATIR Optical/NIR afterglow confirmation
  81. GRB 130306A: Confirmation of the X-ray Afterglow
  82. GRB 130310A: RATIR Observations
  83. Swift Trigger 552142 is a noise event
  84. Konus-Wind observation of GRB 130327B
  85. GRB 130327B: Fermi-LAT detection of a burst
  86. GRB 130327B: Fermi GBM detection
  87. Swift Trigger 552142: a possible GRB
  88. GRB 130327B: gamma-ray detection by AGILE
  89. GRB 130327A: Swift-BAT refined analysis
  90. GRB 130327A: Gemini Observations
  91. GRB 130327A: Swift-XRT refined Analysis
  92. GRB 130327A: Weihai optical obsevations
  93. GRB 130327A: Swift/UVOT Upper Limits
  94. Konus-Wind observation of GRB 130325A
  95. GRB 130327A: ISON-NM optical upper limit
  96. GRB 130325A Tiled Swift observations
  97. GRB 130327A: Enhanced Swift-XRT position
  98. GRB 130327A: RATIR Optical and NIR Observations
  99. GRB 130327A: PAIRITEL NIR Afterglow Candidate
  100. GRB 130325A: Fermi LAT detection

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