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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"

19547 results found.

  1. GRB 100401A: Fermi GBM detection
  2. GRB 100401A Burst, possibly short, detected in ground analysis of BAT data
  3. GRB 100331B: BOOTES-3 observations
  4. GRB 100331B: Swift/UVOT Upper Limits
  5. GRB 100331B: Swift/XRT possible afterglow candidate
  6. Swift detection of LS V +44 17
  7. INTEGRAL trigger 5994 / GRB 100331A: GROND detection of a variable source
  8. GRB 100331A: BOOTES-3 observations
  9. Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
  10. GRB 100325A: Fermi LAT detection
  11. GROND observations of GRB100316D/SN2010bh
  12. GRB 100325A: Fermi GBM detection
  13. GRB 100324A: GROND observations
  14. GRB 100324A found in ground analysis of BAT data
  15. GRB 100322B or possible Galactic transient detected in ground analysis of BAT data
  16. SGR 1833-0832: Swift/UVOT Upper Limits
  17. SGR 1833-0832: Archival Chandra Observations
  18. Discovery of the Spin Period of SGR 1833-0832
  19. GRB 100316D: ATCA radio observations
  20. Probable SGR 1833-0832: Enhanced Swift-XRT position
  21. Swift-BAT refined analysis of the probable new SGR 1833-0832
  22. GRB 100219A: MASTER-Net optical alert observations
  23. GRB 100319A: Swift detection of a burst; possible SGR
  24. GRB 100316D: Possible Supernova
  25. GRB 100219A: optical upper limit
  26. GRB 100316A: optical observations in CrAO
  27. GRB 100316D: Swift/UVOT Observations
  28. GRB 100316D: Swift XRT enhanced position and further refined analysis
  29. GRB 100316C: GROND Detection of a Optical/NIR Afterglow Candidate
  30. GRB 100316D: GROND Detection of the Optical/NIR Afterglow Candidate
  31. GRB 100316D: Gemini/GMOS and VLT/X-shooter observations
  32. GRB 100316D: VLT/X-shooter observations
  33. GRB100316C: Swift/UVOT Upper Limits
  34. GRB 100316B: Swift/UVOT observations
  35. GRB 100316C: Enhanced Swift-XRT position
  36. GRB 100316A: TAROT Calern observatory optical observations
  37. GRB 100316B: Enhanced Swift-XRT position
  38. GRB100316A: Swift/UVOT Upper Limits
  39. Trigger 416140 is almost certainly not a GRB
  40. GRB 100316C: BOOTES-3 observations
  41. GRB 100316D: Swift detection of a burst
  42. GRB 100316B: GROND Detection of the Optical/NIR Afterglow Candidate
  43. GRB 100316C: Swift detection of a burst
  44. GRB 100316A: Enhanced Swift-XRT position
  45. GRB 100316B: Swift detection of a burst with optical counterpart
  46. GRB 100316A: Swift/UVOT Observations
  47. GRB100305A: Optical upper limits at IAO
  48. GRB 100305A: Super-LOTIS early observations
  49. GRB 100305A: Swift/UVOT Upper Limits
  50. GRB 100305A Optical Observations
  51. GRB 100305A: Enhanced Swift-XRT position
  52. GRB 100305A: Gemini-N OT candidate
  53. GRB 100305A: PAIRITEL NIR Upper Limits
  54. GRB 100305A: P60 Observations
  55. GRB 100305A: Swift detection of a burst
  56. GRB 100302A: Swift/UVOT Upper Limits
  57. GRB 100302A: Gemini-N OT confirmation
  58. GRB 100302A: Optical observations at Crni Vrh
  59. GRB 100302A: MASTER-Net optical alert observations
  60. GRB 1000302A : A possible afterglow candidate
  61. GRB 100302A: Enhanced Swift-XRT position
  62. GRB 100302A: Swift detection of a burst
  63. GRB 100224B: Fermi GBM detection
  64. GRB 100206A: optical observations in CrAO
  65. GRB 100206A: optical observations in Terskol
  66. GRB 100213B: Mondy optical observations
  67. GRB 100219A: optical observations
  68. GRB 100224A SHB found in ground analysis of BAT data
  69. GRB 100225A: Fermi LAT detection
  70. GRB 100225A: Fermi GBM detection
  71. GRB
  72. GRB 100219A - Gemini South Spectroscopy
  73. GRB100219A Akeno and Okayama MITSuME Optical Observation
  74. GRB 100219A: GROND observations
  75. GRB 100219A: NOT OA observations
  76. GRB 100219A: Enhanced Swift-XRT position
  77. GRB 100219A: Swift/UVOT Detection of the Optical Afterglow
  78. GRB 100219A: Pre-explosion imaging and host candidate
  79. GRB 100219A: Swift/UVOT Detection of a Source near the XRT Position
  80. GRB 100218A : Fermi GBM detection
  81. GRB 100219A: Swift detection of a burst
  82. GRB 100216A: Keck imaging
  83. GRB 100216A Short, hard GRB detected in ground analysis of Swift-BAT data
  84. GRB 100213B: GRT Optical Observation
  85. GRB 100213A: GRT Optical Observation
  86. GRB 100213B: Enhanced Swift-XRT position
  87. GRB 100213B: Gemini-N Observations
  88. GRB 100213B: Swift/UVOT Upper Limits
  89. GRB 100213A: Swift/UVOT Upper Limits
  90. GRB 100213B: PAIRITEL NIR Upper Limits
  91. GRB 100213A: Enhanced Swift-XRT position
  92. GRB 100213A: SARA observations
  93. GRB 100213B: NOT optical observations
  94. GRB 100213B: Swift detection of a burst
  95. GRB 100213A: Swift detection of a burst
  96. GRB 100206A: Second epoch Gemini-north observations and afterglow limits
  97. Swift/UVOT observations of GRB120212A
  98. GRB 100212A: Fermi GBM detection
  99. GRB 100212A: Enhanced Swift-XRT position
  100. GRB 100212A: candidate optical afterglow

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