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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"

37513 results found.

  1. GRB 140423A: Gemini-N redshift
  2. GRB 140419A, LOAO R-band observations
  3. GRB 140423A: ISON-MN early photometry and correction to the GCN circ. 16143
  4. GRB 140423A: Swift/UVOT detection of a possible counterpart
  5. GRB 140423A: Swift-XRT observations
  6. GRB 140423A: ROTSE-III Detection of Optical Counterpart
  7. GRB 140423A optical observations with pODI/WIYN at KPNO
  8. GRB 140423A: optical afterglow candidate
  9. GRB 140423A: Swift detection of a burst
  10. GRB 140419A: Mondy optical observations
  11. GRB 140419A: Refined NOT photometry
  12. GRB 140419A: Continued RATIR Optical and NIR Observations
  13. GRB140419A: NOT optical observations
  14. GRB 140419A: KAIT Refined Analysis
  15. GRB 140419A: Continued RATIR Optical and NIR Observations
  16. Swift Trigger 596641 is not a GRB
  17. Konus-Wind observation of GRB 140419A
  18. GRB 140419A, Optical Observations
  19. GRB 140419A: MITSuME Ishigakijima Optical Observation
  20. GRB 140419A: MITSuME Okayama Optical Observation
  21. GRB 140419A: Swift UVOT refined analysis
  22. GRB 140419A: P60 Observations
  23. GRB 140419A: Swift-XRT refined Analysis
  24. GRB 140419A: Swift-BAT refined analysis
  25. GRB 140419A: T24 optical observations
  26. GRB 140419A: Gemini-N redshift
  27. GRB 140419A: Enhanced Swift-XRT position
  28. GRB140419A: UVOT detects fading afterglow in white but not in u filter
  29. GRB 140419A: CARMA early 3mm detection
  30. GRB 140419A: RATIR Optical and NIR Observations
  31. GRB 140419A: ROTSE-III Detection of Optical Counterpart
  32. GRB 140419A (Swift trigger 596426) : KAIT optical candidate
  33. GRB 140419A: Swift detection of a burst with optical afterglow
  34. Konus-Wind observation of GRB 140416A
  35. IPN Triangulation of GRB 140416A (long/very intense)
  36. GRB 140416A: Fermi GBM detection
  37. GRB 140414A: Swift/UVOT Upper Limit
  38. GRB 140414A: Swift-XRT observations
  39. GRB 140414A: TNG optical observations
  40. GRB 140414A: Swift-BAT refined analysis
  41. GRB 140414A: Short burst found in ground analysis of BAT slew data
  42. GRB 140413A: Swift/UVOT Observations of the Optical Afterglow
  43. GRB 140412A: Swift/UVOT Upper Limits
  44. Konus-Wind observation of GRB 140413A
  45. GRB 140413A: Swift-XRT refined Analysis
  46. GRB 140413A: Swift-BAT refined analysis
  47. GRB 140412A: Swift-XRT refined Analysis
  48. GRB 140412A: Swift-BAT refined analysis
  49. GRB 140413A: TAROT La Silla observatory optical observations
  50. GRB 140413A: Swift-XRT observations
  51. GRB 140412A: Enhanced Swift-XRT position
  52. GRB 140413A: GROND afterglow candidate
  53. Swift Trigger 595616: a possible GRB
  54. GRB 140412A: Swift detection of a burst
  55. GRB 140408A: 1.5m OSN optical upper limit
  56. GRB 140408A: MITSuME Akeno Optical observation
  57. Fermi418277210: iPTF optical observations
  58. GRB 140408A: RATIR Optical Upper Limits
  59. GRB 140408A: Swift-BAT refined analysis
  60. GRB 140408A: GROND Detection of an Afterglow Candidate
  61. GRB 140408A: Swift/UVOT Upper Limits
  62. GRB 140408A: Swift-XRT refined Analysis
  63. GRB 140408A: MITSuME Okayama upper limits
  64. GRB 140408A: Enhanced Swift-XRT position
  65. GRB 140408A: Fermi GBM detection
  66. Swift Trigger 595162: a possible GRB
  67. GRB 140408A: Swift detection of a burst
  68. GRB 140406A: Fermi GBM observation
  69. GRB 140402A: Deep limit on the optical afterglow from Magellan observations
  70. GRB 111225A: Archeological redshift of the Christmas Burst 2011 from GTC
  71. GRB 140402A: Swift/UVOT Upper Limits
  72. GRB 140331A: Continued RATIR Optical and NIR Observations
  73. GRB 140402A: Swift-XRT observations
  74. GRB 140402A: MASTER optical observations
  75. GRB 140402A BAT refined analysis
  76. GRB 140402A : Xinglong TNT upper limit
  77. GRB 140402A: Marginal BAT detection
  78. GRB 140402A: Fermi GBM detection
  79. GRB 140402A: Fermi-LAT detection of a burst
  80. GRB 140219A: Correction to GCN 15885 (Suzaku-WAM fluence)
  81. GRB 140330A: Fermi GBM observation
  82. GRB 140331A: Swift-XRT refined Analysis
  83. GRB 140301A: Zadko observatory - Gingin optical observations
  84. GRB 140331A: Swift-BAT refined analysis
  85. Retraction of the Fermi/LAT high-energy counterpart for GRB 140330A
  86. GRB 140331A: Swift/UVOT Upper Limits
  87. GRB 140302A: TAROT La Silla observatory optical observations
  88. GRB 140323A: Zadko observatory - Gingin optical observations
  89. GRB 140330A: intense and persistent gamma-ray emission detected by AGILE
  90. GRB 140331A: Zadko observatory - Gingin optical observations
  91. Konus-Wind observation of GRB 140330A
  92. GRB 140129B: AAO optical upper limit
  93. GRB 140129A: Mondy optical observations
  94. GRB 140331A: MITSuME Okayama upper limits
  95. GRB 140331A: Enhanced Swift-XRT position
  96. IPN triangulation of GRB 130330A
  97. GRB 140331A: RATIR Optical and NIR Observations
  98. GRB 140331A: Swift detection of a burst
  99. GRB 140330A: Fermi-LAT Detection
  100. GRB 140329A: Fermi-LAT detection

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