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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"

27046 results found.

  1. GRB 130131B: Swift-XRT refined Analysis
  2. GRB 130131B: GROND Upper limits
  3. GRB 130131B: Swift/UVOT Upper Limits
  4. GRB 130131A: Swift-XRT refined Analysis
  5. GRB 130131B: Swift-BAT refined analysis
  6. GRB 130131A: Swift-BAT refined analysis
  7. GRB 130131B: TAROT Calern observatory optical observations
  8. GRB 130131B: Zadko observatory - Gingin optical observations
  9. GRB 130131B: Swift detection of a burst
  10. GRB 130131A - Faulkes Telescope North Observations
  11. GRB 130131A - UKIRT afterglow candidate
  12. GRB 130131A: Swift detection of a burst
  13. Swift/BAT trigger 547142 is new source Swift J1753.7-2544
  14. GRB 130127A: Fermi GBM detection
  15. Swift Trigger 547142: MAXI/GSC upper limit
  16. Swift Trigger 547142: a probable Galactic source
  17. GRB 130122A: Swift/UVOT Detection
  18. GRB 130122A: RATIR Detection
  19. GRB 130122A: Swift-BAT refined analysis
  20. GRB 130122A: Swift-XRT refined Analysis
  21. GRB 130122A: Xinglong optical upper limit
  22. GRB 130122A: T100 observations
  23. GRB 130122A: Swift detection of a burst with an optical counterpart
  24. GRB 121225B: Suzaku WAM observation of the prompt emission
  25. GRB 130102B: MASTER synchronous observations
  26. GRB 130102A: Swift/UVOT Upper Limits
  27. GRB 130102A: P60 Observations
  28. GRB 130102A: Swift-BAT refined analysis
  29. GRB 130102A: Swift-XRT refined Analysis
  30. GRB 130102A: Swift detection of a burst
  31. Swift Trigger 544381 is a noise event
  32. GRB 121229A: Swift-XRT refined Analysis
  33. GRB 121229A, Swift-BAT refined analysis
  34. GRB 121229A: Swift/UVOT Upper Limits
  35. GRB 121229A: VLT/X-shooter redshift
  36. Swift Trigger 544381 is unlikely to be a GRB
  37. GRB 121229A: MAXI/GSC detection
  38. GRB 121229A: GROND detection of the afterglow
  39. GRB 121229A: Swift detection of a burst
  40. GRB 121226A: Swift/UVOT Upper Limits
  41. GRB 121226A: Swift-XRT refined Analysis
  42. GRB 121226A, Swift-BAT refined analysis
  43. GRB 121226A: NOT optical upper limit
  44. GRB 121226A: Optical Observations
  45. GRB 121226A: Zadko observatory - Gingin optical observations
  46. GRB 121226A: BOOTES-4/MET optical observations
  47. GRB 121226A: Swift detection of a burst
  48. IPN Triangulation of GRB 121225B
  49. GRB 121225B: Fermi GBM observation
  50. GRB 121225B: Fermi LAT Detection
  51. Swift-BAT refined analysis of SGR 1E 1841-045 (Trigger=543763)
  52. Trigger 543763: SGR 1E 1841-045: Swift detection of a soft gamma repeater burst (aka Kes 73)
  53. GRB 121217A: Swift-BAT refined analysis
  54. GRB 121217A theoretical estimate of redshift and of supernova occurrence
  55. GRB 121217A: Fermi GBM observation
  56. GRB 121217A: Swift-XRT refined Analysis
  57. GRB 121217A: Swift/UVOT Detection
  58. GRB 121217A: GROND Detection of the Afterglow
  59. GRB 121217A: Swift detection of a burst
  60. GRB 121209A: Swift/UVOT Upper Limits
  61. GRB 121212A: LOAO IzY Observation
  62. GRB 121209A: MAXI/GSC detection
  63. GRB121212A: NOT optical imaging
  64. GRB 121209A: Early CARMA Observations
  65. GRB 121211A: Continued RATIR Optical and NIR Observations, Fading
  66. GRB 121211A: Fermi GBM observation
  67. GRB 121211A: RATIR Optical and NIR Observations
  68. GRB 121212A: RAPTOR Limits During Gamma-Ray Emitting Interval
  69. GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
  70. GRB 121212A: PAIRITEL NIR Observations
  71. GRB 121212A: Swift-XRT refined Analysis
  72. GRB 121212A: P60 Observations
  73. GRB 121212A: optical observations in ISON-NM observatory
  74. GRB121212A: Swift/UVOT Detection
  75. GRB 121212A: Swift-BAT refined analysis
  76. GRB 121211A: Swift-BAT refined analysis
  77. GRB 121212A: Swift detection of a burst
  78. GRB 121211A: Swift/UVOT Detection
  79. GRB 121211A: Swift-XRT refined Analysis
  80. GRB 121211A: Keck/LRIS redshift
  81. GRB 121211A - Faulkes Telescope North afterglow confirmation
  82. GRB 121211A: Swift detection of a burst with an optical counterpart
  83. GRB 121209A: Swift-XRT refined Analysis
  84. GRB 121209A: Swift-BAT refined analysis
  85. GRB121209A: RATIR Optical and NIR Upper Limits
  86. GRB 121209A: GROND optical afterglow candidate
  87. GRB 121209A: Gemini-South imaging
  88. GRB 121209A: PAIRITEL NIR Observations
  89. GRB 121209A: UVOT Observation
  90. GRB 121209A: Swift detection of a burst
  91. GRB 121127A: Suzaku WAM observation of the prompt emission
  92. GRB 121128A: Optical Observations
  93. GRB 121122A: Suzaku WAM observation of the prompt emission
  94. GRB 121202A: Swift/UVOT Upper Limits
  95. GRB 121202A: Swift-XRT refined Analysis
  96. GRB 121202A: Fermi GBM observation
  97. GRB 121202A: Swift-BAT refined analysis
  98. GRB 121202A: Swift-XRT observations
  99. GRB121202A: Swift/UVOT Observations
  100. GRB 121202A: TAROT Calern observatory optical observations

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