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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"

20359 results found.

  1. GRB 090423: NIR photometry and evidence for spectral break
  2. GRB090423, RIMOTS optical upper limits
  3. GRB 090423: Enhanced Swift-XRT position
  4. GRB 090423: Swift-BAT refined analysis
  5. GRB 090422: Swift/UVOT Upper Limits
  6. GRB 090423: UKIRT K-band observations
  7. GRB 090423: P60 Observations
  8. GRB 090418A: R and I band observation
  9. GRB 090423: Swift detection of a burst
  10. GRB 090422: Enhanced Swift-XRT position
  11. GRB 090418B: RTT150 optical observations
  12. GRB 080410: GAO 150cm telescope Optical Observation
  13. GRB 080408A: GAO 150cm telescope Optical Observation
  14. GRB 090422: Swift detection of a burst
  15. GRB 090418A: Swift/UVOT Detection of the Neighbouring Galaxy
  16. GRB 090418B: GRAS002 observatios
  17. GRB 090418A: optical observations
  18. GRB 090418B: GROND observations
  19. GRB 090419: Swift/UVOT Observations
  20. GRB 090418B: Faulkes Telescope North observations
  21. GRB 090418A: Swift/UVOT Observations
  22. GRB 090417B: Swift/UVOT Upper Limits
  23. GRB 090419: Swift-XRT refined analysis
  24. GRB 090419: GROND detection of afterglow candidate
  25. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  26. VLA radio detection of GRB 090418
  27. VLA radio upper limit on GRB 090417B
  28. GRB 090419: Enhanced Swift-XRT position
  29. GRB 090418: Swift XRT refined analysis
  30. GRB 090419: Swift detection of a burst
  31. VLA observations of short burst GRB 090417A
  32. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  33. GRB 090417B: Gemini imaging
  34. GRB 090418: Enhanced Swift-XRT position
  35. GRB 090418: Swift detection of a burst with optical afterglow
  36. GRB 090417B: Subaru NIR Observations
  37. GRB 090417B: MITSuME Okayama optical upper limits
  38. GRB 090417B: optical observations
  39. GRB090417B: optical observations
  40. GRB 090417B: Swift detection of a burst
  41. GRB 090411A: Fermi GBM detection
  42. GRB 090410: GROND upper limits
  43. GRB 090410: MITSuME optical upper limits
  44. GRB 090408b: IPN Triangulation
  45. GRB 090328b: IPN Triangulation
  46. Konus-Wind and Konus-RF observations of GRB 090408b
  47. GRB 090409: Fermi GBM detection
  48. GRB090408, RIMOTS optical upper limits
  49. Swift-BAT trigger 348781: almost certainly not a burst
  50. GRB 090408B: MASTER II-Kourovka optical observations
  51. GRB 090407: GROND upper limits
  52. GRB 090407: VLT observations
  53. GRB 090407: Swift UVOT Upper Limits
  54. GRB 090407: Enhanced Swift-XRT position
  55. GRB 090407: ROTSE-III Optical Limits
  56. GRB 090407: Swift detection of a burst
  57. GRB 090404: GROND upper limits
  58. GRB 090404: further NOT observations
  59. Swift/UVOT observations of GRB090404
  60. GRB 090404: NOT observations
  61. GRB 090404: Enhanced Swift-XRT position
  62. GRB 090404: Swift detection of a burst
  63. GRB 090401B: VLA radio upper limit
  64. GRB 090401B: Upper limits of MITSuME optical observation
  65. GRB090401B, RIMOTS optical upper limits
  66. GRB 090401B: AGILE refined analysis
  67. GRB 090401B: Enhanced Swift-XRT position
  68. AGILE Gamma-ray detection of GRB 090401B
  69. GRB 090401B: Swift detection of a burst
  70. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  71. GRB 090323: Further TLS detections - a break?
  72. GRB 090328: Radio afterglow detection
  73. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  74. GRB090323: Optical observations from NOT
  75. GRB 090328: Swift UVOT observations
  76. GRB 090328: Updated position/optical afterglow candidate
  77. GRB 090323: Radio afterglow detection
  78. GRB 090320B: MASTER-Net prompt optical observations
  79. GRB 090323: Fermi GBM Spectral Analysis
  80. GRB 090323: UVOT Detection of Afterglow
  81. Konus-Wind observation of GRB 090323
  82. GRB 090323: P60 Afterglow Confirmation
  83. GRB 090323: GROND Detection of the Afterglow and Photo-z
  84. GRB 090323: Possible XRT Counterpart
  85. GRB 090320C: Fermi GBM Detection
  86. Further 15GHz observations of GRB090313
  87. X-shooter observations of GRB 090313
  88. GRB 090313: VLT spectroscopy
  89. GRB090313: radio detection with the VLA
  90. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  91. Further radio observation of GRB 090313
  92. GRB 090313: detection with CARMA in 3mm band
  93. GRB090305B: MASTER-net prompt optical short burst observations
  94. GRB 090313: MITSuME Okayama observation
  95. GRB 090313: Additional Gemini-S photometry
  96. GRB 090313: TAROT La Silla observatory optical detection
  97. GRB 090313: Zadko Telescope observations
  98. GRB 090313: Ongoing plateau phase
  99. GRB 090313: Swift-XRT refined analysis
  100. GRB 090313: Swift/UVOT upper limits

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