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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"

23402 results found.

  1. GRB090423: Y-band limit
  2. GRB 090423: Y-band field calibration update/correction
  3. GRB 090423: Swift/BAT spectral lag results
  4. GRB 090424 : TAOS optical detection
  5. GRB 090424: Liverpool Telescope observations
  6. GRB 090424: Optical observations from 1.23m CAHA
  7. GRB 090423: energetic, luminosity and jet break
  8. GRB 090424: MASTER-Net prompt optical observations
  9. GRB 090424: Enhanced Swift-XRT position
  10. GRB 090424: Swift-BAT refined analysis
  11. GRB 090424: Fermi GBM Observation
  12. GRB 090424: Swift detection of a burst with an optical counterpart
  13. GRB090423: Y-band field calibration
  14. GRB 090423 limiting magnitudes
  15. GRB 090423: Near infrared observation at Okayama Observatory
  16. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  17. GRB 090423: GROND detection and preliminary photo-z
  18. GRB 090423: NOT z-band limit
  19. GRB 090423: Swift-XRT refined analysis
  20. GRB090418A Rc-band photometry
  21. GRB090423 - Swift/UVOT upper limits.
  22. GRB 090423: NIR photometry and evidence for spectral break
  23. GRB 090422: Swift-XRT refined analysis
  24. GRB090423, RIMOTS optical upper limits
  25. GRB 090423: Enhanced Swift-XRT position
  26. GRB 090422: Swift/UVOT Upper Limits
  27. GRB 090423: UKIRT K-band observations
  28. GRB 090423: P60 Observations
  29. GRB 090418A: R and I band observation
  30. GRB 090423: Swift detection of a burst
  31. GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
  32. GRB 090422: Enhanced Swift-XRT position
  33. GRB 090418B: RTT150 optical observations
  34. GRB 080410: GAO 150cm telescope Optical Observation
  35. GRB 080408A: GAO 150cm telescope Optical Observation
  36. GRB 090418B: Suzaku WAM observation of the prompt emission
  37. GRB 090422: Swift detection of a burst
  38. GRB 090418C: Fermi GBM Detection
  39. Swift-BAT trigger 349718 is not a burst
  40. GRB 090418B: GRAS002 observatios
  41. GRB 090418B: GROND observations
  42. GRB 090419: Swift/UVOT Observations
  43. GRB 090418B: Faulkes Telescope North observations
  44. GRB 090418A: Swift/UVOT Observations
  45. GRB 090417B: Swift/UVOT Upper Limits
  46. GRB 090419: Swift-XRT refined analysis
  47. GRB 090419: GROND detection of afterglow candidate
  48. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  49. VLA radio detection of GRB 090418
  50. VLA radio upper limit on GRB 090417B
  51. GRB 090419: Enhanced Swift-XRT position
  52. GRB 090418: Swift XRT refined analysis
  53. GRB 090419: Swift detection of a burst
  54. VLA observations of short burst GRB 090417A
  55. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  56. GRB 090417B: Gemini imaging
  57. GRB 090417B: Swift-XRT refined analysis
  58. GRB 090418: Enhanced Swift-XRT position
  59. GRB 090418 Lick Redshift
  60. GRB 090418: Swift detection of a burst with optical afterglow
  61. GRB 090417B: Subaru NIR Observations
  62. GRB 090417B: MITSuME Okayama optical upper limits
  63. GRB090417B: Xinglong TNT optical upper limit
  64. GRB 090417B: optical observations
  65. GRB090417B: optical observations
  66. GRB 090417B: Swift detection of a burst
  67. GRB 090417: 2MASS galaxy within BAT Localization
  68. GRB 090417: Swift detection of a short burst
  69. GRB 090412: Fermi GBM detection
  70. GRB 090411B: Fermi GBM detection
  71. GRB 090411A: Fermi GBM detection
  72. GRB 090410: GROND upper limits
  73. GRB 090410: MITSuME optical upper limits
  74. GRB 090408b: IPN Triangulation
  75. GRB 090328b: IPN Triangulation
  76. GRB 090410: Swift detection of a burst
  77. Konus-Wind and Konus-RF observations of GRB 090408b
  78. GRB090408 : TAOS optical observations
  79. GRB 090409: Fermi GBM detection
  80. GRB090408, RIMOTS optical upper limits
  81. GRB 090408: Xinglong TNT optical Upper Limit
  82. Swift-BAT trigger 348781: almost certainly not a burst
  83. Fermi GBM Detection of a weak source
  84. GRB 090408B: MASTER II-Kourovka optical observations
  85. GRB 090408: Swift detection of a burst
  86. GRB 090407: GROND upper limits
  87. GRB 090407: VLT observations
  88. GRB 090407: Swift UVOT Upper Limits
  89. GRB 090407: Enhanced Swift-XRT position
  90. Konus-Wind and Konus-RF observations of GRB 090406
  91. GRB 090407: ROTSE-III Optical Limits
  92. GRB 090407: Swift detection of a burst
  93. GRB 090405: Fermi GBM Detection
  94. GRB 090403: Fermi GBM detection
  95. GRB 090404: GROND upper limits
  96. GRB 090404: further NOT observations
  97. Swift/UVOT observations of GRB090404
  98. GRB 090404: NOT observations
  99. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  100. GRB 090404: Swift-XRT Team refined analysis

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