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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"

18430 results found.

  1. GRB 120116A: Swift/UVOT Upper Limits
  2. GRB 120116A: Swift-XRT refined Analysis
  3. GRB 120116A: Enhanced Swift-XRT position
  4. AXP 4U 1042+61: Mondy optical observations
  5. GRB 120116A: Mondy optical observations
  6. GRB 120116A: EVLA observations
  7. GRB 120116A: Optical observations at Crni Vrh
  8. GRB 120116A: Swift-BAT refined analysis
  9. GRB 120116A: NOT observations
  10. GRB 120116A: Bassano Bresciano Observatory optical observations
  11. GRB 120116A: MASTER Early optical limit
  12. GRB 120116A: Swift detection of a burst
  13. GRB 120114A found in ground analysis of BAT data
  14. AXP 4U 0142+61: Swift-BAT refined analysis (trigger 511611)
  15. GRB 120106A: optical upper limit
  16. Swift detection of an SGR burst from AXP 4U 0142+61
  17. IPN Triangulation of GRB 120107A
  18. GRB 120106A: Swift/UVOT Upper Limits
  19. GRB 120106A: Bassano Bresciano Observatory optical observations
  20. GRB 120106A: MASTER Early OT marginally detection
  21. GRB 120106A: Swift-XRT refined Analysis
  22. GRB 120106A: Swift-BAT refined analysis
  23. GRB 120106A: Enhanced Swift-XRT position
  24. GRB 120106A: TAROT Calern observatory optical observations
  25. GRB 120106A: MASTER-Tunka optical observations
  26. GRB 120106A: Swift detection of a burst
  27. GRB 111222A: Second Swift observation
  28. GRB111225A: RAPTOR Early Detection of the Optical Counterpart
  29. GRB 120102A: Fermi GBM observation
  30. Konus-Wind observation of GRB 120102A
  31. GRB 120102A: Swift-BAT refined analysis
  32. GRB 120102A: Swift-XRT refined Analysis
  33. GRB 120102A: Swift/UVOT Detection
  34. GRB 120102A: Enhanced Swift-XRT position
  35. GRB 120102A: Swift detection of a burst with an optical counterpart
  36. GRB 111228A, optical observations
  37. Konus-Wind observation of GRB 111228A
  38. GRB 111229A: Swift/UVOT Detection
  39. GRB 111229A: Faulkes Telescope South observations
  40. GRB 111229A: Swift-XRT refined Analysis
  41. GRB 111229A: Enhanced Swift-XRT position
  42. GRB 111229A: Swift-BAT refined analysis
  43. GRB 111229A: Swift detection of a burst
  44. GRB 111225A: Lightbuckets Optical Observations
  45. GRB 111228A: P60 Observations
  46. GRB 111228A: T100 observations
  47. GRB 111228A: Swift-XRT refined Analysis
  48. GRB 111228A: PAIRITEL NIR Detection
  49. GRB 111228A: TAROT La Silla observatory observations
  50. GRB 111228A: MASTER OT observations
  51. GRB 111228A: Swift/UVOT Detection
  52. GRB 111228A, Swift-BAT refined analysis
  53. GRB 111228A: Enhanced Swift-XRT position
  54. GRB 111228A: TAROT Calern observatory. OT decay stopped
  55. GRB 111228A: Fermi GBM observation
  56. GRB 111228A: TAROT Calern observatory. OT seems still bright
  57. GRB 111228A: Swift detection of a burst with an optical counterpart
  58. GRB 111225A: Swift/UVOT Observations
  59. GRB 111215A: Keck/LRIS Imaging
  60. GRB 111225A: Keck/LRIS Afterglow Photometry
  61. GRB 111225A: PAIRITEL NIR Upper Limits
  62. GRB 111225A: GRT Optical Observation
  63. GRB 111225A: Swift-XRT refined Analysis
  64. GRB 111225A, Swift-BAT refined analysis
  65. GRB 111225A: Enhanced Swift-XRT position
  66. GRB 111225A: TAROT Calern observatory optical detection
  67. GRB 111225A: TAROT Calern observatory optical observations
  68. GRB 111225A: Swift detection of a burst with an optical counterpart
  69. GRB 111222A: Swift/UVOT Observations
  70. GRB 111222A: Swift-XRT observations
  71. IPN Triangulation of GRB 111222A (short/hard/intense)
  72. Trigger 510075 is not a GRB
  73. GRB 111215A: EVLA observations
  74. GRB111215A: CARMA Detection
  75. XRT GRB Catalogue now live and online
  76. GRB 111103B: optical upper limit
  77. GRB 110820A: optical observations in Maidanak observatory
  78. GRB 111103A: optical upper limit of Mt. Terskol observatory
  79. GRB 111215B: Suzaku WAM observation of the prompt emission
  80. GRB111215A: optical upper limit
  81. GRB 111215B: Swift/UVOT Upper Limits
  82. GRB 111215B: Swift-XRT observations
  83. GRB 111205A: Confirmation of X-ray Afterglow
  84. IPN Triangulation of GRB 111215B (long/intense)
  85. GRB 111215A: Swift/UVOT Upper Limits
  86. GRB 111215A: Swift-XRT refined Analysis
  87. Possible detection of pre-trigger X-ray emission from GRB 111215A by MAXI/GSC
  88. GRB 111215A: Enhanced Swift-XRT position
  89. GRB 111215A: Swift-BAT refined analysis
  90. GRB 111215A: MASTER-Net optical prompt and follow up observations
  91. GRB 111215A, Optical Observations
  92. GRB 111209A: RAPTOR Limits Before and During the Gamma-ray Emitting Interval
  93. GRB 111215A: Swift detection of a burst
  94. GRB 111212A: GROND observations
  95. GRB 111211A: Swift/UVOT Detection
  96. GRB 111212A: Swift-XRT refined Analysis
  97. GRB 111211A: Swift/XRT target of opportunity observation
  98. GRB 111212A: Swift/UVOT Upper Limits
  99. GRB 111212A: Swift-BAT refined analysis
  100. GRB 111212A: Enhanced Swift-XRT position

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