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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"

19549 results found.

  1. INTEGRAL Alert n. 5995: MASTER-Net optical observations
  2. GRB 100331B: GROND Upper limits
  3. GRB 100401A: Fermi GBM detection
  4. GRB 100401A Burst, possibly short, detected in ground analysis of BAT data
  5. GRB 100331B: BOOTES-3 observations
  6. GRB 100331B: Swift/UVOT Upper Limits
  7. GRB 100331B: Swift/XRT possible afterglow candidate
  8. Swift detection of LS V +44 17
  9. INTEGRAL trigger 5994 / GRB 100331A: GROND detection of a variable source
  10. GRB 100331A: BOOTES-3 observations
  11. Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
  12. GRB 100325A: Fermi LAT detection
  13. GROND observations of GRB100316D/SN2010bh
  14. GRB 100325A: Fermi GBM detection
  15. GRB 100324A: GROND observations
  16. GRB 100324A found in ground analysis of BAT data
  17. GRB 100322B or possible Galactic transient detected in ground analysis of BAT data
  18. SGR 1833-0832: Swift/UVOT Upper Limits
  19. SGR 1833-0832: Archival Chandra Observations
  20. Discovery of the Spin Period of SGR 1833-0832
  21. GRB 100316D: ATCA radio observations
  22. Probable SGR 1833-0832: Enhanced Swift-XRT position
  23. Swift-BAT refined analysis of the probable new SGR 1833-0832
  24. GRB 100219A: MASTER-Net optical alert observations
  25. GRB 100319A: Swift detection of a burst; possible SGR
  26. GRB 100316D: Possible Supernova
  27. GRB 100219A: optical upper limit
  28. GRB 100316A: optical observations in CrAO
  29. GRB 100316D: Swift/UVOT Observations
  30. GRB 100316D: Swift XRT enhanced position and further refined analysis
  31. GRB 100316C: GROND Detection of a Optical/NIR Afterglow Candidate
  32. GRB 100316D: GROND Detection of the Optical/NIR Afterglow Candidate
  33. GRB 100316D: Gemini/GMOS and VLT/X-shooter observations
  34. GRB 100316D: VLT/X-shooter observations
  35. GRB100316C: Swift/UVOT Upper Limits
  36. GRB 100316B: Swift/UVOT observations
  37. GRB 100316C: Enhanced Swift-XRT position
  38. GRB 100316A: TAROT Calern observatory optical observations
  39. GRB 100316B: Enhanced Swift-XRT position
  40. GRB100316A: Swift/UVOT Upper Limits
  41. Trigger 416140 is almost certainly not a GRB
  42. GRB 100316C: BOOTES-3 observations
  43. GRB 100316D: Swift detection of a burst
  44. GRB 100316B: GROND Detection of the Optical/NIR Afterglow Candidate
  45. GRB 100316C: Swift detection of a burst
  46. GRB 100316A: Enhanced Swift-XRT position
  47. GRB 100316B: Swift detection of a burst with optical counterpart
  48. GRB 100316A: Swift/UVOT Observations
  49. GRB100305A: Optical upper limits at IAO
  50. GRB 100305A: Super-LOTIS early observations
  51. GRB 100305A: Swift/UVOT Upper Limits
  52. GRB 100305A Optical Observations
  53. GRB 100305A: Enhanced Swift-XRT position
  54. GRB 100305A: Gemini-N OT candidate
  55. GRB 100305A: PAIRITEL NIR Upper Limits
  56. GRB 100305A: P60 Observations
  57. GRB 100305A: Swift detection of a burst
  58. GRB 100302A: Swift/UVOT Upper Limits
  59. GRB 100302A: Gemini-N OT confirmation
  60. GRB 100302A: Optical observations at Crni Vrh
  61. GRB 100302A: MASTER-Net optical alert observations
  62. GRB 1000302A : A possible afterglow candidate
  63. GRB 100302A: Enhanced Swift-XRT position
  64. GRB 100302A: Swift detection of a burst
  65. GRB 100224B: Fermi GBM detection
  66. GRB 100206A: optical observations in CrAO
  67. GRB 100206A: optical observations in Terskol
  68. GRB 100213B: Mondy optical observations
  69. GRB 100219A: optical observations
  70. GRB 100224A SHB found in ground analysis of BAT data
  71. GRB 100225A: Fermi LAT detection
  72. GRB 100225A: Fermi GBM detection
  73. GRB
  74. GRB 100219A - Gemini South Spectroscopy
  75. GRB100219A Akeno and Okayama MITSuME Optical Observation
  76. GRB 100219A: GROND observations
  77. GRB 100219A: NOT OA observations
  78. GRB 100219A: Enhanced Swift-XRT position
  79. GRB 100219A: Swift/UVOT Detection of the Optical Afterglow
  80. GRB 100219A: Pre-explosion imaging and host candidate
  81. GRB 100219A: Swift/UVOT Detection of a Source near the XRT Position
  82. GRB 100218A : Fermi GBM detection
  83. GRB 100219A: Swift detection of a burst
  84. GRB 100216A: Keck imaging
  85. GRB 100216A Short, hard GRB detected in ground analysis of Swift-BAT data
  86. GRB 100213B: GRT Optical Observation
  87. GRB 100213A: GRT Optical Observation
  88. GRB 100213B: Enhanced Swift-XRT position
  89. GRB 100213B: Gemini-N Observations
  90. GRB 100213B: Swift/UVOT Upper Limits
  91. GRB 100213A: Swift/UVOT Upper Limits
  92. GRB 100213B: PAIRITEL NIR Upper Limits
  93. GRB 100213A: Enhanced Swift-XRT position
  94. GRB 100213A: SARA observations
  95. GRB 100213B: NOT optical observations
  96. GRB 100213B: Swift detection of a burst
  97. GRB 100213A: Swift detection of a burst
  98. GRB 100206A: Second epoch Gemini-north observations and afterglow limits
  99. Swift/UVOT observations of GRB120212A
  100. GRB 100212A: Fermi GBM detection

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