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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"
  1. GRB 070429A: optical observations
  2. GRB070429B: position correction
  3. GRB 070309: Swift-XRT afterglow confirmation
  4. GRB070429B: possible host galaxy detection
  5. VLA observation of GRB 070429B
  6. Swift/UVOT observations of GRB070429B
  7. GRB 070429B, Swift-BAT refined analysis
  8. Swift/UVOT observations of GRB070429A
  9. GRB 070429A: Swift XRT refined analysis
  10. GRB 070429A, Swift-BAT refined analysis
  11. GRB 070429A: optical and NIR observations
  12. GRB 070429B: Swift XRT refined analysis
  13. GRB 070429B: ROTSE-III Optical Limits
  14. GRB 070429B: Swift detection of a short burst
  15. GRB 070429: What's the temperature?
  16. GRB 070429: ROTSE-III Optical Limits
  17. GRB 070429: Swift detection of a burst
  18. GRB 070427, Swift-BAT Refined Analysis
  19. LT monitoring of GRB070412
  20. GRB 070427: Swift detection of a burst
  21. GRB 070411, further deep LBT photometry
  22. GRB 070411: Late-time Keck imaging
  23. GRB 070411 : Planned XMM-Newton observation
  24. GRB070419B: Suzaku WAM observation of the prompt emission
  25. GRB 070420, SMARTS optical/IR afterglow observations
  26. GRB 070411, deep LBT photometry
  27. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  28. Konus-Wind observation of GRB 070420
  29. GRB 070411: break in the optical light curve
  30. GRB 070420 Swift-BAT Refined Analysis
  31. GRB070419A: Kuiper Optical detection
  32. GRB070419a: Swift UVOT observations
  33. GRB 070419A: MARGE Observations
  34. GRB 070420: optical rebrightening observed at Mt. John
  35. GRB 070420: Swift XRT refined analysis
  36. GRB070420: Swift UVOT continuing observations
  37. GRB 070411: BART early limit
  38. GRB 070420: Faulkes Telescope South Observations
  39. GBR 070419A: Swift/XRT refined analysis
  40. GRB 070420: TAROT La Silla observatory optical observations
  41. GRB 070420: NIR and optical afterglow confirmed
  42. GRB 070420: Swift detection of a burst with optical afterglow
  43. GRB 070419A: MITSuME Okayama Observations
  44. GRB 070419A: Early Super-LOTIS Observations
  45. GRB 070419B, Swift-BAT refined analysis
  46. GRB 070419A Swift-BAT Refined Analysis
  47. GRB070419B: Confirmation of Optical Transient
  48. GRB 070419A: RAPTOR Detection of Early Emission
  49. GRB 070419B: Swift XRT refined analysis
  50. GRB 070419: Keck/LRIS Absorption Redshift
  51. GRB 070419B: optical afterglow confirmation
  52. GRB 070419A, Optical observations
  53. GRB 070411: Deep VLT detection
  54. GRB070419 - SDSS Pre-Burst Observations
  55. GRB 070419A: SARA observations
  56. GRB 070419A: NAYUTA Optical Observation
  57. GRB 070419A: Faulkes Telescope North Optical Observations
  58. GRB 070419B optical afterglow candidate
  59. GRB 070419A: Optical and IR observations with KANATA
  60. GRB 070419B: optical afterglow candidate
  61. GRB 070419A: Lulin Optical observation
  62. GRB070419A, optical observation
  63. Infrared detection of GRB070419A with UKIRT
  64. GRB 070419A: Kiso Optical observation
  65. GRB070330: Correction to UVOT position
  66. GRB 070419: P60 Confirmation of Optical Afterglow
  67. GRB 070419B: Swift detection of a burst
  68. GRB 070419 optical afterglow candidate
  69. GRB 070419A: ROTSE-III Optical Limits
  70. GRB 070419: Swift detection of a burst
  71. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  72. GRB 070418: Optical and IR observations with KANATA
  73. Trigger 276045: Swift detection of a possible burst
  74. GRB 070406: Swift XRT refined analysis
  75. IBAS Alert n.4202: not a real GRB
  76. GRB 070318, SMARTS optical/IR afterglow observations
  77. GRB 070411: TLS data shows plateau, flares
  78. GRB070412: UKIRT-WFCAM JHK upper limits
  79. GRB070412: Swift UVOT observations
  80. IBAS Alert n.4199: Not a GRB
  81. GRB 070411: Swift/UVOT observations
  82. GRB 070412, Swift-BAT refined analysis
  83. GRB 070412 Liverpool Telescope optical limit
  84. GRB 070411: Optical photometry at Crni Vrh
  85. GRB 070412: Swift-XRT refined analysis
  86. GRB 070411: Swift-XRT refined analysis
  87. GRB 070412: further reanalysis of NOT images
  88. GRB 070412: Optical observations at Crni Vrh
  89. GRB 070411: OA redshift
  90. GRB 070412: Swift-XRT refined position
  91. GRB 070412: further NOT observations
  92. GRB 070412: Gemini/GMOS afterglow candidate
  93. GRB 070412: IAC80 optical afterglow candidate
  94. GRB 070411: Magellan/Clay photometry
  95. GRB 070411: Magellan/IMACS photometry
  96. GRB 070412: NOT observations
  97. GRB 070412: Nearby bright galaxy
  98. GRB 070411, Swift-BAT refined analysis
  99. GRB 070412: Swift detection of a burst
  100. GRB 070411: IAC80 optical observations

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