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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"

19808 results found.

  1. GRB 090407: VLT observations
  2. GRB 090407: Swift UVOT Upper Limits
  3. GRB 090407: Enhanced Swift-XRT position
  4. GRB 090407: ROTSE-III Optical Limits
  5. GRB 090407: Swift detection of a burst
  6. GRB 090404: GROND upper limits
  7. GRB 090404: further NOT observations
  8. Swift/UVOT observations of GRB090404
  9. GRB 090404: NOT observations
  10. GRB 090404: Enhanced Swift-XRT position
  11. GRB 090404: Swift detection of a burst
  12. GRB 090401B: VLA radio upper limit
  13. GRB 090401B: Upper limits of MITSuME optical observation
  14. GRB090401B, RIMOTS optical upper limits
  15. GRB 090401B: AGILE refined analysis
  16. GRB 090401B: Enhanced Swift-XRT position
  17. AGILE Gamma-ray detection of GRB 090401B
  18. GRB 090401B: Swift detection of a burst
  19. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  20. GRB 090323: Further TLS detections - a break?
  21. GRB 090328: Radio afterglow detection
  22. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  23. GRB090323: Optical observations from NOT
  24. GRB 090328: Swift UVOT observations
  25. GRB 090328: Updated position/optical afterglow candidate
  26. GRB 090323: Radio afterglow detection
  27. GRB 090320B: MASTER-Net prompt optical observations
  28. GRB 090323: Fermi GBM Spectral Analysis
  29. GRB 090323: UVOT Detection of Afterglow
  30. Konus-Wind observation of GRB 090323
  31. GRB 090323: P60 Afterglow Confirmation
  32. GRB 090323: GROND Detection of the Afterglow and Photo-z
  33. GRB 090323: Possible XRT Counterpart
  34. GRB 090320C: Fermi GBM Detection
  35. Further 15GHz observations of GRB090313
  36. X-shooter observations of GRB 090313
  37. GRB 090313: VLT spectroscopy
  38. GRB090313: radio detection with the VLA
  39. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  40. Further radio observation of GRB 090313
  41. GRB 090313: detection with CARMA in 3mm band
  42. GRB090305B: MASTER-net prompt optical short burst observations
  43. GRB 090313: MITSuME Okayama observation
  44. GRB 090313: Additional Gemini-S photometry
  45. GRB 090313: TAROT La Silla observatory optical detection
  46. GRB 090313: Zadko Telescope observations
  47. GRB 090313: Ongoing plateau phase
  48. GRB 090313: Swift-XRT refined analysis
  49. GRB 090313: Swift/UVOT upper limits
  50. GRB 090306B: Confirmation of the X-ray afterglow
  51. GRB 090313, GROND observations
  52. GRB 090313: Swift detection of a burst
  53. GRB 090313: Swift detection of a burst
  54. Swift trigger 346250 is probably not a burst
  55. GRB 090205: Zadko Telescope late-time observations
  56. GRB 090309A: GROND upper limits
  57. GRB 090307A: TAROT Calern observatory optical observations
  58. GRB 090309: Swift/UVOT Upper Limits
  59. GRB 090309: Enhanced Swift-XRT position
  60. GRB 090308: GROND observations
  61. GRB 090308: Gemini GMOS Observations
  62. GRB 090309: Swift detection of a burst
  63. GRB 090308: Swift/UVOT Upper Limits
  64. GRB 090307: GROND Upper Limits
  65. GRB 090306B: GROND Upper Limits
  66. GRB 090308: Swift-XRT refined analysis
  67. GRB 090308: Swift detection of a burst
  68. GRB 090306B: Possible XRT afterglow
  69. GRB 090307: Swift-XRT afterglow confirmation and analysis
  70. Swift Trigger 345551 is probably not a GRB
  71. IPN localization of short GRB 090305C
  72. GRB 090306: Swift detection of a possible burst
  73. GRB 090305: Swift/UVOT Upper Limits
  74. GRB 090305: Swift-XRT refined analysis
  75. GRB090305: GMOS-S Candidate Optical Afterglow
  76. GRB 090305: Swift detection of a short burst
  77. Konus-Wind observation of bright short GRB 090227B
  78. Konus-Wind observation of GRB 090301A
  79. GRB 081211B: Nearby cluster
  80. Ongoing activity of AXP/SGR 1E1547.0-5408
  81. GRB090217: XRT analysis
  82. Konus-Wind observation of GRB 090217
  83. SGR activity seen by BAT during ICSP Ionospheric Events
  84. VLA radio upper limit on GRB 090205
  85. GRB 090205: Swift/UVOT Upper Limits
  86. GRB 090205: GROND observations and photometric redshift estimate
  87. GRB 090205: VLT candidate afterglow
  88. GRB 090205: Enhanced Swift-XRT position
  89. GRB 090205: Swift detection of a burst
  90. GRB090201: Swift UVOT upper limits
  91. GRB 090201: object inside the enhanced XRT error circle
  92. GRB 090201: Enhanced Swift-XRT position
  93. GRB 090201: VLT NIR observations
  94. GRB 090201: Swift-BAT refined analysis
  95. GRB 090201: VLT afterglow candidate
  96. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  97. GRB 090201: ROTSE-III Optical Limits
  98. GRB 090126A: Swift/UVOT Upper Limits
  99. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  100. Suzaku ToO Observation of AXP 1E 1547.0-5408

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