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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"

6410 results found.

  1. GRB 130502B: Swift-XRT refined Analysis
  2. Trigger 555096: Swift detection of a possible burst
  3. GRB 130427A: Non-observation of VHE emission with HAWC
  4. GRB 130502A: Swift-XRT refined Analysis
  5. GRB 130502A: Fermi GBM detection
  6. GRB 130502B Swift-XRT observations
  7. GRB 130502B: Fermi LAT Detection
  8. GRB 130502B: Fermi GBM detection of a burst
  9. GRB 130427A: Fermi-LAT refined analysis
  10. GRB 130427A: Improved Swift-XRT analysis
  11. GRB 130425: MASTER-Net optical observations
  12. GRB 130427A: Nishi-Harima NIR Observations
  13. GRB 130427B: Tentative VLT/X-shooter redshift
  14. GRB 130427A, Optical Observations
  15. GRB 130427A: Swift-XRT refined Analysis
  16. GRB 130427B: Swift-XRT refined Analysis
  17. GRB 130427A: Fermi GBM observation
  18. GRB 130427A: Fermi-LAT detection of a burst
  19. GRB 130427A: PAIRITEL NIR Detections
  20. GRB 130425A: Fermi GBM detection
  21. GRB 130420A: ROTSE-III data analysis
  22. GRB 130420B: Fermi GBM observation
  23. GRB 130420B: Swift-XRT refined Analysis
  24. GRB 130420A: Fermi GBM observation
  25. GRB 130420A: ISON-NM optical observations
  26. GRB 130420A: Swift-XRT refined Analysis
  27. GRB 130420A: PAIRITEL NIR detections
  28. GRB 130418A: Swift-XRT refined Analysis
  29. GRB 130418A: T18 and T21 optical observations
  30. GRB 130418A, Swift-BAT refined analysis
  31. GRB 130418A: REM NIR observations
  32. GRB 130418A: Swift detection of a burst with an optical counterpart
  33. GRB 130408A: Swift-XRT refined Analysis
  34. Swift/XRT observation of GRB 130327B
  35. GRB 130306A: Confirmation of the X-ray Afterglow
  36. Swift Trigger 552142 is a noise event
  37. GRB 130327B: Fermi-LAT detection of a burst
  38. GRB 130327B: Fermi GBM detection
  39. Swift Trigger 552142: a possible GRB
  40. GRB 130327A: Swift-XRT refined Analysis
  41. GRB 130327A: PAIRITEL NIR Afterglow Candidate
  42. GRB 130325A: Fermi LAT detection
  43. GRB 130325A: Fermi GBM detection
  44. GRB 130315A: Swift-XRT refined Analysis
  45. Swift XRT observations of GRB 130310A
  46. GRB 130313A: Fading X-ray Afterglow
  47. GRB 130313A: Swift-XRT refined Analysis
  48. Swift XRT observations of GRB 130310A
  49. GRB 130306A: Swift Detection of a Possible Afterglow
  50. GRB 130310A: Fermi GBM detection
  51. GRB 130305A: Further Swift-XRT Observations
  52. GRB 130307A: Fermi GBM detection
  53. GRB 130305A: Swift/XRT detection of the afterglow
  54. GRB 130305A: Fermi GBM observation
  55. GRB 130216A: Swift/XRT observations
  56. GRB 130219A: Fermi GBM detection
  57. GRB 130216B: Swift/XRT observations
  58. GRB 130216A: Fermi GBM observation
  59. GRB 130216B: Fermi GBM observation
  60. GRB 130216B: P200 NIR Observations
  61. GRB 130216A: P200 NIR Observations
  62. GRB 130215A: Additional P200 NIR observations
  63. GRB 130215A: P200 NIR observations
  64. GRB 130215A: Fermi GBM detection
  65. GRB 130215A: iTelescope T11 observations
  66. GRB 130215A: REM NIR observations
  67. Swift GRB130206A: late XRT observations.
  68. GRB 121128A: optical observations
  69. GRB 130211A: Swift-XRT refined Analysis
  70. GRB 130206A: Fermi LAT Observations
  71. GRB 130206A: Fermi GBM observation
  72. GRB 130206A: XRT and UVOT follow-up observations.
  73. GRB 130206A: Swift-XRT observations
  74. GRB 130131B: Swift-XRT refined Analysis
  75. GRB 130131A: Swift-XRT refined Analysis
  76. GRB 130127A: Fermi GBM detection
  77. GRB 130122A: Swift-XRT refined Analysis
  78. GRB 130102A: Swift-XRT refined Analysis
  79. GRB 121229A: Swift-XRT refined Analysis
  80. GRB 121226A: Swift-XRT refined Analysis
  81. GRB 121226A: Optical Observations
  82. GRB 121225B: Fermi GBM observation
  83. GRB 121225B: Fermi LAT Detection
  84. GRB 121217A theoretical estimate of redshift and of supernova occurrence
  85. GRB 121217A: Fermi GBM observation
  86. GRB 121217A: Swift-XRT refined Analysis
  87. GRB 121209A: LOAO Observation
  88. GRB121212A: NOT optical imaging
  89. GRB 121211A: Fermi GBM observation
  90. GRB 121212A: PAIRITEL NIR Observations
  91. GRB 121212A: Swift-XRT refined Analysis
  92. GRB 121211A: Swift-XRT refined Analysis
  93. GRB 121209A: Swift-XRT refined Analysis
  94. GRB 121209A: GROND optical afterglow candidate
  95. GRB 121209A: PAIRITEL NIR Observations
  96. GRB 121202A: Swift-XRT refined Analysis
  97. GRB 121202A: Fermi GBM observation
  98. GRB 121201A: GROND afterglow observations and photometric redshift
  99. GRB 121201A: Swift-XRT refined Analysis
  100. GRB 121128A: Swift-XRT refined Analysis

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