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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"

37513 results found.

  1. GRB 100206A: Enhanced Swift-XRT position
  2. GRB 100206A: Pre-explosion imaging and host candidate
  3. GRB 100206A: Swift detection of a short hard burst
  4. GRB 100205A: Gemini-N + NIRI photometry
  5. GRB 100130B: Fermi GBM detection
  6. GRB 100113A: Fermi GBM detection
  7. GRB 100205A: Swift-BAT refined analysis
  8. GRB 100205A: Swift UVOT upper limits
  9. GRB 100205A: Swift XRT refined analysis
  10. GRB 100203A: Swift XRT and UVOT refined analyses
  11. GRB 100205A: Enhanced Swift-XRT position
  12. GRB 100205A Gemini-North IR afterglow candidate
  13. GRB 100205A: Gemini-South Observations
  14. GRB 100205A: Super-LOTIS early observations
  15. GRB 100131A: Suzaku WAM observation of the prompt emission
  16. GRB 100205A: NOT optical observations
  17. GRB 100205A: Swift detection of a burst
  18. GRB 100203A Detected in Ground Analysis of BAT Data
  19. Short X-ray Transient detected by MAXI/GSC
  20. GRB 100131A: Fermi GBM detection
  21. GRB 100119A: Suzaku WAM observation of the prompt emission
  22. Konus-Wind observation of GRB 100119A
  23. GRB 100122A: Fermi GBM detection
  24. GRB 100122A: MASTER-Net optical observations
  25. GRB 100116A: Suzaku WAM observation of the prompt emission
  26. GRB 100115A: Swift-XRT refined analysis
  27. GRB 100119A: Swift-BAT refined analysis
  28. GRB091109A: VLT/FORS2 spectroscopic redshift
  29. GRB 100117A: candidate optical afterglow
  30. GRB 100119A: Swift detection of a burst
  31. Konus-Wind observation of GRB 100116A
  32. GRB 100117A: Gemini North spectroscopy
  33. GRB 100117A: Fermi GBM detection
  34. Swift/UVOT refined analysis of GRB100117A
  35. GRB 100117A: Optical object inside the revised XRT error circle
  36. GRB 100117A: Swift-XRT refined analysis
  37. GRB 100117A: Gemini-North upper limit
  38. GRB 100117A: Magellan IMACS imaging
  39. GRB 100117A: Gemini South Imaging and CFHT Pre-Explosion Images
  40. GRB 100117A: Swift-BAT refined analysis
  41. GRB 100117A: Swift detection of a short hard burst
  42. GRB 100115A: Gemini-N photometry
  43. GRB 100115A: Enhanced Swift-XRT position
  44. GRB 100116A: Fermi LAT detection
  45. GRB 100115A: SARA Astrometry
  46. GRB 100116A: Fermi GBM detection
  47. NOT observation of GRB100115A localization
  48. GRB 100115A: SARA Afterglow Candidate
  49. GRB 100115A: Swift/UVOT Upper Limits
  50. GRB 100115A: Swift-XRT candidate afterglow
  51. GRB 100115A detected in ground analysis of Swift-BAT data
  52. GRB 100111A: PAIRITEL NIR Upper Limits
  53. GRB 100111A: Swift UVOT Refined Analysis
  54. GRB 100111A: Swift-BAT refined analysis
  55. GRB 100111A: Enhanced Swift-XRT position
  56. GRB100111A: Swift-XRT refined analysis
  57. GRB 100111A: Fermi GBM observation
  58. GRB 100111A: NOT optical observations
  59. GRB 100111A: Swift detection of a burst with an optical afterglow
  60. GRB 100103A: GROND Upper Limits
  61. GRB 100103A: Swift-XRT team refined analysis
  62. GRB 100103A - UVOT-enhanced XRT position
  63. Konus-Wind observation of GRB 100103A
  64. GRB 100103A: Swift/UVOT Upper Limits
  65. GRB 100103A: Correction to Swift position error
  66. GRB 100103A: Swift/XRT position
  67. GRB 100103A: a long GRB detected with INTEGRAL
  68. Swift Trigger 381591 is probably not a burst
  69. GRB 091231: GROND NIR observations
  70. GRB 091230: Swift/UVOT Observations
  71. GRB 091230: Swift-XRT observation
  72. GRB 091230: GROND optical/NIR afterglow candidate
  73. GRB 091230: a long GRB detected by INTEGRAL
  74. Swift Trigger 381434 is not a GRB
  75. Trigger 381434: Swift detection of a possible burst
  76. GRB 091221 : IRSF NIR upper limit
  77. GRB 091221: Skynet/PROMPT Detections
  78. GRB 091221: Fermi GBM Observation
  79. GRB 091117: Swift-XRT late time observations
  80. GRB 091221 Swift-BAT refined analysis
  81. GRB 091221: Swift/UVOT refined analysis
  82. GRB 091221: Swift-XRT refined analysis
  83. GRB 091221: Enhanced Swift-XRT position
  84. GRB 091221, GROND observations
  85. GRB 091221: UVOT Confirmation of an Optical Afterglow
  86. GRB 091221: ROTSE-III Detection of Optical Counterpart
  87. GRB 091221: Swift detection of a burst
  88. Swift trigger 379449 (possible GRB) is not a burst
  89. GRB 091215: Faulkes Telescope North observations
  90. Trigger 379449: Swift detection of a possible burst
  91. GRB 091208B: Xinglong TNT optical observation
  92. GRB 091208A: Suzaku WAM observation of the prompt emission
  93. GRB 091208A: GAO 150cm telescope Optical Observation
  94. Konus-Wind observation of GRB 091208A
  95. GRB 091208B: GAO 150cm telescope Optical Observation
  96. GRB 091208B: optical observations
  97. GRB 091208B: Keck HIRES redshift confirmation
  98. GRB 091208B: GROND observations
  99. GRB 091208A: Swift-XRT observations
  100. GRB 091208B: Swift-XRT refined analysis

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