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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"

19533 results found.

  1. GRB 120118B: Swift-XRT position
  2. GRB 120118B: MASTER optical observations
  3. GRB 120118B: Swift detection of a burst
  4. GRB 120116A: Swift/UVOT Upper Limits
  5. GRB 120116A: Swift-XRT refined Analysis
  6. GRB 120116A: Enhanced Swift-XRT position
  7. AXP 4U 1042+61: Mondy optical observations
  8. GRB 120116A: Mondy optical observations
  9. GRB 120116A: EVLA observations
  10. GRB 120116A: Optical observations at Crni Vrh
  11. GRB 120116A: Swift-BAT refined analysis
  12. GRB 120116A: NOT observations
  13. GRB 120116A: Bassano Bresciano Observatory optical observations
  14. GRB 120116A: MASTER Early optical limit
  15. GRB 120116A: Swift detection of a burst
  16. GRB 120114A found in ground analysis of BAT data
  17. AXP 4U 0142+61: Swift-BAT refined analysis (trigger 511611)
  18. GRB 120106A: optical upper limit
  19. Swift detection of an SGR burst from AXP 4U 0142+61
  20. IPN Triangulation of GRB 120107A
  21. GRB 120106A: Swift/UVOT Upper Limits
  22. GRB 120106A: Bassano Bresciano Observatory optical observations
  23. GRB 120106A: MASTER Early OT marginally detection
  24. GRB 120106A: Swift-XRT refined Analysis
  25. GRB 120106A: Swift-BAT refined analysis
  26. GRB 120106A: Enhanced Swift-XRT position
  27. GRB 120106A: TAROT Calern observatory optical observations
  28. GRB 120106A: MASTER-Tunka optical observations
  29. GRB 120106A: Swift detection of a burst
  30. GRB 111222A: Second Swift observation
  31. GRB111225A: RAPTOR Early Detection of the Optical Counterpart
  32. GRB 120102A: Fermi GBM observation
  33. Konus-Wind observation of GRB 120102A
  34. GRB 120102A: Swift-BAT refined analysis
  35. GRB 120102A: Swift-XRT refined Analysis
  36. GRB 120102A: Swift/UVOT Detection
  37. GRB 120102A: Enhanced Swift-XRT position
  38. GRB 120102A: Swift detection of a burst with an optical counterpart
  39. GRB 111228A, optical observations
  40. Konus-Wind observation of GRB 111228A
  41. GRB 111229A: Swift/UVOT Detection
  42. GRB 111229A: Faulkes Telescope South observations
  43. GRB 111229A: Swift-XRT refined Analysis
  44. GRB 111229A: Enhanced Swift-XRT position
  45. GRB 111229A: Swift-BAT refined analysis
  46. GRB 111229A: Swift detection of a burst
  47. GRB 111225A: Lightbuckets Optical Observations
  48. GRB 111228A: P60 Observations
  49. GRB 111228A: T100 observations
  50. GRB 111228A: Swift-XRT refined Analysis
  51. GRB 111228A: PAIRITEL NIR Detection
  52. GRB 111228A: TAROT La Silla observatory observations
  53. GRB 111228A: MASTER OT observations
  54. GRB 111228A: Swift/UVOT Detection
  55. GRB 111228A, Swift-BAT refined analysis
  56. GRB 111228A: Enhanced Swift-XRT position
  57. GRB 111228A: TAROT Calern observatory. OT decay stopped
  58. GRB 111228A: Fermi GBM observation
  59. GRB 111228A: TAROT Calern observatory. OT seems still bright
  60. GRB 111228A: Swift detection of a burst with an optical counterpart
  61. GRB 111225A: Swift/UVOT Observations
  62. GRB 111215A: Keck/LRIS Imaging
  63. GRB 111225A: Keck/LRIS Afterglow Photometry
  64. GRB 111225A: PAIRITEL NIR Upper Limits
  65. GRB 111225A: GRT Optical Observation
  66. GRB 111225A: Swift-XRT refined Analysis
  67. GRB 111225A, Swift-BAT refined analysis
  68. GRB 111225A: Enhanced Swift-XRT position
  69. GRB 111225A: TAROT Calern observatory optical detection
  70. GRB 111225A: TAROT Calern observatory optical observations
  71. GRB 111225A: Swift detection of a burst with an optical counterpart
  72. GRB 111222A: Swift/UVOT Observations
  73. GRB 111222A: Swift-XRT observations
  74. IPN Triangulation of GRB 111222A (short/hard/intense)
  75. Trigger 510075 is not a GRB
  76. GRB 111215A: EVLA observations
  77. GRB111215A: CARMA Detection
  78. XRT GRB Catalogue now live and online
  79. GRB 111103B: optical upper limit
  80. GRB 110820A: optical observations in Maidanak observatory
  81. GRB 111103A: optical upper limit of Mt. Terskol observatory
  82. GRB 111215B: Suzaku WAM observation of the prompt emission
  83. GRB111215A: optical upper limit
  84. GRB 111215B: Swift/UVOT Upper Limits
  85. GRB 111215B: Swift-XRT observations
  86. GRB 111205A: Confirmation of X-ray Afterglow
  87. IPN Triangulation of GRB 111215B (long/intense)
  88. GRB 111215A: Swift/UVOT Upper Limits
  89. GRB 111215A: Swift-XRT refined Analysis
  90. Possible detection of pre-trigger X-ray emission from GRB 111215A by MAXI/GSC
  91. GRB 111215A: Enhanced Swift-XRT position
  92. GRB 111215A: Swift-BAT refined analysis
  93. GRB 111215A: MASTER-Net optical prompt and follow up observations
  94. GRB 111215A, Optical Observations
  95. GRB 111209A: RAPTOR Limits Before and During the Gamma-ray Emitting Interval
  96. GRB 111215A: Swift detection of a burst
  97. GRB 111212A: GROND observations
  98. GRB 111211A: Swift/UVOT Detection
  99. GRB 111212A: Swift-XRT refined Analysis
  100. GRB 111211A: Swift/XRT target of opportunity observation

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