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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"
  1. Swift detection of a possible burst (trigger 332287)
  2. GRB 081012 - Enhanced Swift XRT position
  3. GRB 081017, Swift-BAT refined analysis
  4. GRB 081017: REM early observations
  5. GRB 081017: Swift detection of a burst
  6. GRB 081016B, Swift-BAT refined analysis
  7. GRB 081016B: Swift/UVOT Upper Limits
  8. GRB 081011: Swift XRT refined analysis
  9. GRB 081016B: Swift-XRT Team refined Analysis
  10. GRB 081016B: Enhanced Swift-XRT position
  11. GRB 081016B: ROTSE-III Optical Limits
  12. GRB 081016B: Swift detection of a burst
  13. GRB 081011: Enhanced Swift-XRT position
  14. GRB 081016: Swift-XRT candidate afterglow detection
  15. Swift detection of flare on CC Eri
  16. GRB 081016: A long GRB discovered by INTEGRAL
  17. Trigger 331721 Due to Swift startracker loss-of-lock
  18. Detection of flare star Algol in Swift-BAT slew data
  19. GRB 081009: Fermi GBM detection
  20. GRB 081012: GROND upper limits
  21. GRB 081008: Galaxy associated with z=1.967 absorber
  22. Swift-BAT triggered on the flare star Algol
  23. GRB 081012: Fermi GBM detection
  24. GRB 081007 and GRB 081007B: Fermi GBM detection
  25. GRB 080430: optical observations
  26. GRB 081008 optical upper limit
  27. GRB 081012: Observations from NOT
  28. GRB 081012: Swift/UVOT analysis of initial observations
  29. GRB 081012: Swift/XRT detection
  30. GRB 081012, Swift-BAT refined analysis
  31. GRB 081012: ROTSE-III Optical Limits
  32. GRB 081012: Swift detection of a burst
  33. Revised table for GRB 081011 UVOT detections
  34. GRB081011: UVOT detection of an optical afterglow
  35. GRB 081011: Swift/XRT detection
  36. GRB 081011, Swift-BAT refined analysis
  37. GRB 081008, SMARTS optical/IR afterglow observations
  38. GRB 081011: Swift detection of a burst
  39. GRB 081007: Radio Detection
  40. Konus-Wind observation of GRB 081001
  41. GRB 081007: Rapid PROMPT Detections
  42. GRB 081008, Swift-BAT refined analysis
  43. GRB 081008: VLT redshift confirmation
  44. GRB 081008: Swift-XRT Refined Analysis
  45. GRB081008: Swift/UVOT observations
  46. GRB 081008: Enhanced Swift-XRT position
  47. GRB 081008: Gemini-South Absorption Redshiftt
  48. GRB 081008: VLT/FORS2 spectroscopy
  49. GRB 081008: Swift detection of a burst with optical afterglow
  50. GRB 081008: ROTSE-III Detection of Optical Counterpart
  51. GRB081006B: Fermi GBM detection
  52. GRB081006: Fermi GBM detection
  53. GRB081007: Swift/UVOT Observations
  54. GRB 081007, SMARTS optical afterglow observations
  55. GRB 081007, Swift-BAT refined analysis
  56. GRB 081007: Early RAPTOR measurements of optical counterpart
  57. GRB 081007: Swift-XRT Team refined analysis
  58. GRB 081007: Gemini-south redshift
  59. GRB 081007: Enhanced Swift-XRT position
  60. GRB 081007, Faulkes Telescope North optical observations
  61. GRB 081007, SMARTS optical/IR afterglow observations
  62. GRB 081007: REM NIR and optical counterpart
  63. GRB 081007: Swift detection of a burst with optical afterglow
  64. GRB081003C: GLAST Burst Monitor detection
  65. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  66. INTEGRAL ToO observation of the AXP 1E 1547.0-5408
  67. GRB 081003B: TAROT Calern observatory optical observations
  68. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  69. GRB 081003B: Swift-XRT upper limit
  70. GRB 081003A: OSN optical observations
  71. GRB 081001: Further observations from OSN
  72. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  73. GRB081003B: Optical limits from Spain
  74. GRB 081003A: Swift-XRT Team position and analysis
  75. Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
  76. GRB 081003B: a long GRB detected with INTEGRAL
  77. GRB 080928: Fermi GBM detection
  78. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  79. GRB 081003: A long GRB discovered by INTEGRAL
  80. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  81. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  82. Trigger 330353: Swift detection of a Galactic short soft burst
  83. GRB 081001: Observations from OSN
  84. GRB 080925: Suzaku WAM observation of the prompt emission
  85. GRB 081001: Swift UVOT Observations
  86. GRB 081001: Swift-XRT position
  87. GRB081001: optical limit from ASH-Centurion
  88. GRB081001: SuperAGILE Localization of a long GRB
  89. GRB080928: redshift retraction
  90. GRB 080928: Watcher observations
  91. GRB 080927: Fermi GBM detection
  92. GRB 080928: VLT redshift
  93. GRB080928: Gemini-South Absorption Redshift
  94. GRB 080928: Swift-XRT refined analysis
  95. GRB 080928: Swift/UVOT observations
  96. GRB 080928, Swift-BAT final refined analysis
  97. GRB 080928: GROND DETECTION
  98. GRB 080928: Enhanced Swift-XRT position
  99. GRB 080928, Swift-BAT initial refined analysis
  100. GRB 080928A: ROTSE-III Confirmation of Optical Counterpart

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