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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"

3402 results found.

  1. GRB 090418: PAIRITEL NIR detection
  2. GRB 090417B: Subaru NIR Observations
  3. GRB 090407: Swift-XRT refined analysis
  4. GRB 090404: Swift-XRT Team refined analysis
  5. Swift/UVOT observations of GRB090401B
  6. Swift/UVOT observations of GRB090401B
  7. GRB 090401B: Swift XRT Refined Analysis
  8. GRB 090328: Swift XRT refined analysis
  9. GRB 090323: UVOT Detection of Afterglow
  10. GRB 090323: Swift-XRT refined analysis
  11. GRB 090323: GROND Detection of the Afterglow and Photo-z
  12. GRB 090313: Light curve steepening
  13. GRB 090313 - PAIRITEL NIR detections
  14. GRB 090313: Swift-XRT refined analysis
  15. GRB 090313: Faulkes Telescope North observations
  16. GRB 090306B: Confirmation of the X-ray afterglow
  17. GRB 090309: Swift-XRT refined analysis
  18. GRB 090308: Swift-XRT refined analysis
  19. GRB 090306B: Possible XRT afterglow
  20. GRB 090307: Swift-XRT afterglow confirmation and analysis
  21. GRB 090305: Swift-XRT refined analysis
  22. GRB 090205: Swift-XRT refined analysis
  23. GRB 090201: Swift-XRT refined analysis
  24. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  25. GRB 090126A: Swift/UVOT Upper Limits
  26. GRB 090126A: Swift-XRT Refined Analysis
  27. GRB 090123: Swift XRT refined analysis
  28. GRB 090118: Swift-XRT observations
  29. GRB090118 Swift/UVOT upper limits
  30. GRB090117 Swift/UVOT upper limits
  31. GRB090117: Swift-XRT detection of a possible candidate afterglow
  32. GRB 090113: Swift-XRT refined analysis
  33. GRB 090111: Swift-XRT refined analysis
  34. GRB 090107B: Swift XRT afterglow confirmation
  35. GRB 090107B: Swift-XRT detection of possible afterglow
  36. GRB 090102: Swift XRT refined analysis
  37. GRB081230: Swift-XRT refined analysis
  38. GRB 081228: Swift-XRT Team refined analysis
  39. GRB 081226B: Swift XRT and UVOT upper limits
  40. GRB 081226: Swift-XRT refined analysis
  41. GRB 081224: Swift-XRT observation
  42. GRB 081211B: Further Swift-XRT analysis
  43. Possible GRB 081211B: Swift/UVOT Upper Limits
  44. Possible GRB 081211B - Swift-XRT analysis
  45. GRB 081211: Swift XRT refined analysis
  46. GRB 081211: Swift/UVOT detection of an optical afterglow
  47. GRB 081210: Swift-XRT refined analysis
  48. GRB 081204: Swift XRT afterglow confirmation
  49. Swift-XRT observations of GRB 081203B
  50. GRB081203A: Swift-XRT refined analysis
  51. GRB 081203B: Swift-XRT candidate afterglow.
  52. GRB 081128: Swift-XRT refined analysis
  53. GRB 081127: Swift-XRT refined analysis
  54. GRB 081126: Swift-XRT refined analysis
  55. GRB 081121: Swift-XRT refined analysis
  56. GRB 081118: Swift-XRT refined analysis
  57. GRB 081109A: confirmation of possible detection host galaxy
  58. Further Swift-XRT observations of the probable GRB 081105.
  59. GRB 081025: Swift-XRT further analysis
  60. GRB 081024B: Swift-XRT late-time observations
  61. GRB 081109A: Swift-XRT refined analysis
  62. GRB 081028 - PAIRITEL NIR detection
  63. GRB 081104: refined XRT analysis
  64. GRB 081102: Swift-XRT refined analysis
  65. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  66. GRB 081024B: new Swift-XRT observations
  67. GRB081029: Swift XRT refined analysis
  68. GRB 081028: Swift-XRT refined analysis
  69. GRB 081024B: Swift-XRT further observations
  70. Swift UVOT observations of GRB081024B
  71. GRB 081025: Swift-XRT position
  72. GRB 081024B: Swift-XRT observations
  73. GRB 081016A: Swift-XRT refined analysis
  74. GRB 081011: Swift XRT refined analysis
  75. GRB 081016B: Swift-XRT Team refined Analysis
  76. GRB 081016: Swift-XRT candidate afterglow detection
  77. GRB 081008: Swift-XRT Refined Analysis
  78. GRB 081007: Swift-XRT Team refined analysis
  79. GRB 081003B: Swift-XRT upper limit
  80. GRB 081003A: Swift-XRT Team position and analysis
  81. GRB 081001: Swift UVOT Observations
  82. GRB 081001: Swift-XRT position
  83. GRB080928: Gemini-South Absorption Redshift
  84. GRB 080928: Swift-XRT refined analysis
  85. Swift trigger 325707: Swift-XRT upper limit
  86. GRB 080919: Swift/UVOT Refined Analysis
  87. GRB 080919: Swift-XRT refined analysis
  88. GRB 080916C: IRSF/SIRUS NIR Observation
  89. GRB 080916C: Swift XRT refined analysis
  90. GRB 080916B: Swift-XRT refined analysis
  91. GRB 080916A: Swift XRT refined analysis
  92. GRB 080915: Swift-XRT afterglow detection and analysis
  93. GRB 080913: Swift-XRT refined analysis
  94. GRB 080906: Swift-XRT Refined Analysis
  95. GRB 080905A: Swift-XRT Refined Analysis
  96. GRB 080903: Swift-XRT Refined Analysis
  97. SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
  98. SGR 0501+4516: Detection of possible optical counterpart
  99. SGR 0501+4516: WHT observations of the possible near-infrared counterpart
  100. GRB080825B: Swift/UVOT Upper Limits

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