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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"

17850 results found.

  1. GRB 100111A: PAIRITEL NIR Upper Limits
  2. GRB 100111A: Swift UVOT Refined Analysis
  3. GRB 100111A: Enhanced Swift-XRT position
  4. GRB 100111A: NOT optical observations
  5. GRB 100111A: Swift detection of a burst with an optical afterglow
  6. Swift/BAT Detects an Outburst from XTE J1901+014
  7. GRB 100103A: GROND Upper Limits
  8. GRB 100103A - UVOT-enhanced XRT position
  9. GRB 100103A: Swift/XRT position
  10. GRB 091231: GROND NIR observations
  11. Swift Trigger 381591: Uncatalogued UVOT Source
  12. GRB 091230: Swift/UVOT Observations
  13. Trigger 381591: Swift detection of a possible burst
  14. GRB 091230: Swift-XRT observation
  15. GRB 091230: GROND optical/NIR afterglow candidate
  16. Swift Trigger 381434 is not a GRB
  17. Trigger 381434: Swift detection of a possible burst
  18. GRB 091117: Swift-XRT late time observations
  19. GRB 091221: Swift/UVOT refined analysis
  20. GRB 091221: Enhanced Swift-XRT position
  21. GRB 091221: UVOT Confirmation of an Optical Afterglow
  22. GRB 091221: Swift detection of a burst
  23. GRB 091215: Faulkes Telescope North observations
  24. Trigger 379449: Swift detection of a possible burst
  25. GRB 091208A: GAO 150cm telescope Optical Observation
  26. GRB091208A: Swift/UVOT refined analysis
  27. GRB 091208B: optical observations
  28. GRB 091208B: GROND observations
  29. GRB 091208A: Swift-XRT observations
  30. GRB091208B: NOT optical observations
  31. GRB 091208A, RIMOTS optical upper limits
  32. GRB 091208B: MITSuME Akeno Optical Observation
  33. GRB 091208B: Enhanced Swift-XRT position
  34. GRB 091208B: MITSuME Okayama Optical Observation
  35. GRB 091208B, RIMOTS optical upper limits
  36. GRB 091208B: Swift detection of a burst with an optical afterglow
  37. GRB 091208B: BOOTES-3 optical afterglow
  38. GRB 091202: GTC & CAHA optical/nIR afterglow candidate
  39. GRB 091109A: GROND confirmation of redshift z = 3.5
  40. GRB 091127, SMARTS optical/IR afterglow observations
  41. GRB 091202: Swift/UVOT Upper Limits
  42. GRB 091202 - UVOT-enhanced XRT position
  43. GRB 091127: Zadko Telescope Observations
  44. GRB 091202: TAROT Calern observatory optical observations
  45. GRB 091117: Chandra Observations
  46. GRB 091130B: Swift/UVOT Upper Limits
  47. GRB 091127: Skynet/PROMPT Observations of Fading
  48. GRB 091130B: Enhanced Swift-XRT position
  49. GRB 091130B: Swift detection of a burst
  50. GRB 091127: Radio observations
  51. GRB 091127: TAROT La Silla observatory optical observations
  52. GRB 091127: LABOCA/APEX submm observations
  53. GRB 091127: Further NOT optical observations
  54. GRB 091127: Fermi GBM detection
  55. GRB 091127: MASTER early optical transient polarimetry
  56. GRB 091127: Swift-XRT afterglow detection and analysis
  57. GRB 091127: TAROT La Silla observatory optical decay
  58. GRB 091127: Swift/UVOT observations
  59. GRB 091127: NOT observations
  60. GRB 091127 : GROND observations
  61. GRB 091127: REM NIR afterglow detection
  62. GRB 091117: TNG optical observations
  63. GRB 091117A: Swift/UVOT followup observations
  64. GRB 091117: Evidence for Variability of XRT Source #1
  65. GRB091117: Gemini South Observations
  66. GRB 091117: Swift XRT refined analysis
  67. GRB091111: Swift XRT refined analysis
  68. GRB 091031: Fermi LAT detection of a faint burst
  69. GRB 091111: BOOTES-3 contemporaneous imaging
  70. GRB 091111: BOOTES-3 observations
  71. GRB 091109A: GROND and VLT observations
  72. GRB 091109B: Swift/UVOT Upper Limits
  73. GRB 091109B: Enhanced Swift-XRT position
  74. GRB 091109B: Optical limits from Watcher
  75. GRB 091109B: ROTSE-III Optical Limits
  76. GRB 091109B: Swift detection of a short burst
  77. GRB 091109: BOOTES-3 observations
  78. GRB 091109: Swift/UVOT observations
  79. GRB 091109: Faulkes Telescope South observations
  80. GRB 091109: Enhanced Swift-XRT position
  81. GRB091109: REM detection of the NIR afterglow
  82. GRB 091109: Swift detection of a burst with optical afterglow
  83. GRB 091029: Observations from Stardome Observatory
  84. GRB 091104: Swift/UVOT Upper Limits
  85. GRB 091104: Enhanced Swift-XRT position
  86. GRB 091104: Swift detection of a burst
  87. GRB 091102: LABOCA/APEX submm observations
  88. Fermi LAT Upper Limits on GRB 091010
  89. GRB 091102 : Faulkes Telescope South Upper Limits
  90. GRB 091102: Swift/UVOT Upper Limits
  91. GRB 091102: GROND Upper Limits
  92. GRB 091102: BOOTES-3 observations
  93. GRB 091102: Swift/XRT localization
  94. GRB 091024: optical observations
  95. GRB 091024: Fermi LAT upper limits
  96. GRB 091018, SMARTS optical/IR afterglow observations
  97. GRB091029: Swift/UVOT observations
  98. GRB 091029: Enhanced Swift-XRT position
  99. GRB091024 optical observations
  100. GRB 091029: GROND Detection of the Optical/NIR Afterglow

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