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

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