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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"

43604 results found.

  1. GRB 091127: Detection of a Supernova
  2. GRB 100205A: Keck limits on an underlying host galaxy
  3. GRB 100205A: BOAO/LOAO zYJK observation
  4. GRB 100205B: Fermi GBM detection
  5. GRB 100206A: GROND upper limits
  6. GRB 100206A: Gemini-North observations
  7. GRB 100131A: MASTER-Net optical alert observations
  8. GRB 100206A: MASTER-Net optical alert observations
  9. GRB 100206A: PAIRITEL Photometry of Host Candidate
  10. GRB 100206A - Keck/LRIS Spectroscopy
  11. GRB 100206A: NOT NIR observations
  12. GRB 100206A: WHT candidate afterglow
  13. GRB 100206A: optical observations from Southern Spain
  14. GRB 100205A: GROND upper limits
  15. GRB 100206A: Swift-XRT refined analysis
  16. GRB 100206A: Fermi GBM observation
  17. GRB 100206A: Optical limit
  18. GRB 100206A: Swift-BAT refined analysis
  19. GRB 100206A: Enhanced Swift-XRT position
  20. GRB 100206A: Pre-explosion imaging and host candidate
  21. GRB 100206A: Swift detection of a short hard burst
  22. GRB 100205A: Gemini-N + NIRI photometry
  23. GRB 100130B: Fermi GBM detection
  24. GRB 100113A: Fermi GBM detection
  25. GRB 100205A: Swift-BAT refined analysis
  26. GRB 100205A: Swift UVOT upper limits
  27. GRB 100205A: Swift XRT refined analysis
  28. GRB 100203A: Swift XRT and UVOT refined analyses
  29. GRB 100205A: Enhanced Swift-XRT position
  30. GRB 100205A Gemini-North IR afterglow candidate
  31. GRB 100205A: Gemini-South Observations
  32. GRB 100205A: Super-LOTIS early observations
  33. GRB 100131A: Suzaku WAM observation of the prompt emission
  34. GRB 100205A: NOT optical observations
  35. GRB 100205A: Swift detection of a burst
  36. GRB 100203A Detected in Ground Analysis of BAT Data
  37. Short X-ray Transient detected by MAXI/GSC
  38. GRB 100131A: Fermi GBM detection
  39. GRB 100119A: Suzaku WAM observation of the prompt emission
  40. Konus-Wind observation of GRB 100119A
  41. GRB 100122A: Fermi GBM detection
  42. GRB 100122A: MASTER-Net optical observations
  43. GRB 100116A: Suzaku WAM observation of the prompt emission
  44. GRB 100115A: Swift-XRT refined analysis
  45. GRB 100119A: Swift-BAT refined analysis
  46. GRB091109A: VLT/FORS2 spectroscopic redshift
  47. GRB 100117A: candidate optical afterglow
  48. GRB 100119A: Swift detection of a burst
  49. Konus-Wind observation of GRB 100116A
  50. GRB 100117A: Gemini North spectroscopy
  51. GRB 100117A: Fermi GBM detection
  52. GRB 100117A: Optical object inside the revised XRT error circle
  53. GRB 100117A: Swift-XRT refined analysis
  54. GRB 100117A: Gemini-North upper limit
  55. GRB 100117A: Magellan IMACS imaging
  56. GRB 100117A: Gemini South Imaging and CFHT Pre-Explosion Images
  57. GRB 100117A: Swift-BAT refined analysis
  58. GRB100117A: Possible afterglow from NOT observation
  59. GRB 100117A: Swift detection of a short hard burst
  60. GRB 100115A: Gemini-N photometry
  61. GRB 100115A: Enhanced Swift-XRT position
  62. GRB 100116A: Fermi LAT detection
  63. GRB 100115A: SARA Astrometry
  64. GRB100115A: Revision of NOT observation
  65. GRB 100116A: Fermi GBM detection
  66. NOT observation of GRB100115A localization
  67. GRB 100115A: SARA Afterglow Candidate
  68. GRB 100115A: Swift/UVOT Upper Limits
  69. GRB 100115A: Swift-XRT candidate afterglow
  70. GRB 100115A detected in ground analysis of Swift-BAT data
  71. GRB 100111A: PAIRITEL NIR Upper Limits
  72. GRB 100111A: Swift UVOT Refined Analysis
  73. GRB 100111A: Swift-BAT refined analysis
  74. GRB 100111A: Enhanced Swift-XRT position
  75. GRB100111A: Swift-XRT refined analysis
  76. GRB 100111A: Fermi GBM observation
  77. GRB 100111A: NOT optical observations
  78. GRB 100111A: Swift detection of a burst with an optical afterglow
  79. Swift/BAT Detects an Outburst from XTE J1901+014
  80. Swift Trigger #382159 is due to XTE J1752-223
  81. GRB 100103A: GROND Upper Limits
  82. GRB 100103A: Swift-XRT team refined analysis
  83. GRB 100103A - UVOT-enhanced XRT position
  84. Konus-Wind observation of GRB 100103A
  85. GRB 100103A: Correction to Swift position error
  86. GRB 100103A: Swift/XRT position
  87. GRB 100103A: a long GRB detected with INTEGRAL
  88. Swift Trigger 381591 is probably not a burst
  89. GRB 091231: GROND NIR observations
  90. Swift Trigger 381591: Uncatalogued UVOT Source
  91. GRB 091230: Swift/UVOT Observations
  92. Trigger 381591: Swift detection of a possible burst
  93. GRB 091230: Swift-XRT observation
  94. GRB 091230: GROND optical/NIR afterglow candidate
  95. GRB 091230: a long GRB detected by INTEGRAL
  96. Swift Trigger 381434 is not a GRB
  97. Trigger 381434: Swift detection of a possible burst
  98. GRB 091221 : IRSF NIR upper limit
  99. GRB 091221: Skynet/PROMPT Detections
  100. GRB 091221: Fermi GBM Observation

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