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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"

26309 results found.

  1. GRB 100119A: Swift detection of a burst
  2. Konus-Wind observation of GRB 100116A
  3. GRB 100117A: Fermi GBM detection
  4. GRB 100117A: Optical object inside the revised XRT error circle
  5. GRB 100117A: Gemini-North upper limit
  6. GRB 100117A: Magellan IMACS imaging
  7. GRB 100117A: Gemini South Imaging and CFHT Pre-Explosion Images
  8. GRB 100117A: Swift-BAT refined analysis
  9. GRB 100117A: Swift detection of a short hard burst
  10. GRB 100115A: Enhanced Swift-XRT position
  11. GRB 100116A: Fermi LAT detection
  12. GRB 100115A: SARA Astrometry
  13. GRB 100116A: Fermi GBM detection
  14. NOT observation of GRB100115A localization
  15. GRB 100111A: Swift UVOT Refined Analysis
  16. GRB 100111A: Swift-BAT refined analysis
  17. GRB 100111A: Enhanced Swift-XRT position
  18. GRB 100111A: Fermi GBM observation
  19. GRB 100111A: Swift detection of a burst with an optical afterglow
  20. Swift/BAT Detects an Outburst from XTE J1901+014
  21. Swift Trigger #382159 is due to XTE J1752-223
  22. GRB 100103A: Swift-XRT team refined analysis
  23. GRB 100103A - UVOT-enhanced XRT position
  24. Konus-Wind observation of GRB 100103A
  25. GRB 100103A: a long GRB detected with INTEGRAL
  26. Swift Trigger 381591 is probably not a burst
  27. GRB 091231: GROND NIR observations
  28. GRB 091230: Swift/UVOT Observations
  29. Trigger 381591: Swift detection of a possible burst
  30. GRB 091230: Swift-XRT observation
  31. GRB 091230: GROND optical/NIR afterglow candidate
  32. GRB 091230: a long GRB detected by INTEGRAL
  33. Trigger 381434: Swift detection of a possible burst
  34. GRB 091221 : IRSF NIR upper limit
  35. GRB 091221: Fermi GBM Observation
  36. GRB 091117: Swift-XRT late time observations
  37. GRB 091221 Swift-BAT refined analysis
  38. GRB 091221: Enhanced Swift-XRT position
  39. GRB 091221: UVOT Confirmation of an Optical Afterglow
  40. GRB 091221: Swift detection of a burst
  41. GRB 091215: Faulkes Telescope North observations
  42. Trigger 379449: Swift detection of a possible burst
  43. GRB 091208A: Suzaku WAM observation of the prompt emission
  44. Konus-Wind observation of GRB 091208A
  45. GRB091208A: Swift/UVOT refined analysis
  46. GRB 091208B: GROND observations
  47. GRB 091208B: Swift-XRT refined analysis
  48. GRB091208B: Swift/UVOT refined analysis
  49. GRB 091208B: Fermi GBM observation
  50. GRB 091208B, Swift-BAT refined analysis
  51. GRB 091208A Swift-BAT refined analysis
  52. GRB 091208B: Faulkes Telescope North and South Optical Afterglow
  53. GRB 091208B: Enhanced Swift-XRT position
  54. GRB 091208B: MITSuME Okayama Optical Observation
  55. GRB 091208B: Swift detection of a burst with an optical afterglow
  56. GRB 091208: Swift detection of a burst
  57. Short X-ray Transient, RIMOTS optical upper limits
  58. A small revision to the GRB-naming convention
  59. GRB 091123: Suzaku WAM observation of the prompt emission
  60. GRB 091109A: GROND confirmation of redshift z = 3.5
  61. GRB091127: Continuing Swift/UVOT Observations
  62. GRB 091127, SMARTS optical/IR afterglow observations
  63. GRB091202: Swift-XRT refined analysis
  64. GRB 091202 - UVOT-enhanced XRT position
  65. GRB 091126A: Suzaku WAM observation of the prompt emission
  66. GRB 091202: TAROT Calern observatory optical observations
  67. GRB 091202: a long GRB detected by INTEGRAL
  68. GRB 091127: redshift confirmation with X-shooter
  69. GRB 091117: Chandra Observations
  70. GRB 091020: MASTER-Net optical polarization observations
  71. Short X-ray Transient Detection by MAXI/GSC
  72. Konus-Wind observation of very long GRB 091123
  73. GRB 091123: Fermi GBM detection of a very long burst
  74. GRB 091126B: Fermi GBM detection
  75. GRB 091127: Suzaku WAM observation of the prompt emission
  76. GRB 091126: Fermi GBM detection
  77. GRB 091130B: Swift-XRT team refined analysis
  78. GRB 091130B: Swift-BAT refined analysis
  79. GRB 091127: Skynet/PROMPT Observations of Fading
  80. GRB 091130B: Enhanced Swift-XRT position
  81. GRB 091130B: Swift detection of a burst
  82. GRB 091130: Swift detection of a possible burst
  83. GRB 091127: Radio observations
  84. GRB 091128: Fermi GBM detection
  85. Konus-Wind observation of GRB 091127
  86. GRB 091127: TAROT La Silla observatory optical observations
  87. GRB 091127: Fermi GBM detection
  88. GRB 091127: TAROT La Silla observatory optical decay
  89. GRB 091127: CAHA 1.23m I-band observations
  90. GRB 091127: Swift-BAT refined analysis
  91. GRB 091127 : GROND observations
  92. GRB 091127: Swift detection of a burst
  93. IPN Triangulation of GRB091120
  94. Konus-Wind observation of GRB 091120
  95. GRB 091120: MAXI GSC detection
  96. GRB 091120: Fermi GBM observation
  97. GRB 091117A: Suzaku WAM observation of the prompt emission
  98. GRB 091117: TNG optical observations
  99. GRB 091117A: Swift/UVOT followup observations
  100. GRB 091117 BAT refined analysis

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