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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 070506, Swift-BAT Refined Analysis
  2. GRB 070506: Swift detection of a burst with optical afterglow
  3. GRB 070412, deep LBT imaging
  4. GRB 070429A: Swift XRT further analysis
  5. GRB070429B: VLT observations
  6. GRB 070429A: optical observations
  7. GRB070429B: position correction
  8. GRB 070309: Swift-XRT afterglow confirmation
  9. GRB070429B: possible host galaxy detection
  10. VLA observation of GRB 070429B
  11. Swift/UVOT observations of GRB070429B
  12. GRB 070429B, Swift-BAT refined analysis
  13. Swift/UVOT observations of GRB070429A
  14. GRB 070429A: Swift XRT refined analysis
  15. GRB 070429A, Swift-BAT refined analysis
  16. GRB 070429A: optical and NIR observations
  17. GRB 070429B: Swift XRT refined analysis
  18. GRB 070429B: ROTSE-III Optical Limits
  19. GRB 070429B: Swift detection of a short burst
  20. GRB 070429: What's the temperature?
  21. GRB 070429: ROTSE-III Optical Limits
  22. GRB 070429: Swift detection of a burst
  23. GRB 070427, Swift-BAT Refined Analysis
  24. LT monitoring of GRB070412
  25. GRB 070427: Swift detection of a burst
  26. GRB 070411, further deep LBT photometry
  27. GRB 070411: Late-time Keck imaging
  28. GRB 070411 : Planned XMM-Newton observation
  29. GRB070419B: Suzaku WAM observation of the prompt emission
  30. GRB 070420, SMARTS optical/IR afterglow observations
  31. GRB 070411, deep LBT photometry
  32. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  33. Konus-Wind observation of GRB 070420
  34. GRB 070411: break in the optical light curve
  35. GRB 070420 Swift-BAT Refined Analysis
  36. GRB070419A: Kuiper Optical detection
  37. GRB070419a: Swift UVOT observations
  38. GRB 070419A: MARGE Observations
  39. GRB 070420: optical rebrightening observed at Mt. John
  40. GRB 070420: Swift XRT refined analysis
  41. GRB070420: Swift UVOT continuing observations
  42. GRB 070411: BART early limit
  43. GRB 070420: Faulkes Telescope South Observations
  44. GBR 070419A: Swift/XRT refined analysis
  45. GRB 070420: TAROT La Silla observatory optical observations
  46. GRB 070420: NIR and optical afterglow confirmed
  47. GRB 070420: Swift detection of a burst with optical afterglow
  48. GRB 070419A: MITSuME Okayama Observations
  49. GRB 070419A: Early Super-LOTIS Observations
  50. GRB 070419B, Swift-BAT refined analysis
  51. GRB 070419A Swift-BAT Refined Analysis
  52. GRB070419B: Confirmation of Optical Transient
  53. GRB 070419A: RAPTOR Detection of Early Emission
  54. GRB 070419B: Swift XRT refined analysis
  55. GRB 070419: Keck/LRIS Absorption Redshift
  56. GRB 070419B: optical afterglow confirmation
  57. GRB 070419A, Optical observations
  58. GRB 070411: Deep VLT detection
  59. GRB070419 - SDSS Pre-Burst Observations
  60. GRB 070419A: SARA observations
  61. GRB 070419A: NAYUTA Optical Observation
  62. GRB 070419A: Faulkes Telescope North Optical Observations
  63. GRB 070419B optical afterglow candidate
  64. GRB 070419A: Optical and IR observations with KANATA
  65. GRB 070419B: optical afterglow candidate
  66. GRB 070419A: Lulin Optical observation
  67. GRB070419A, optical observation
  68. Infrared detection of GRB070419A with UKIRT
  69. GRB 070419A: Kiso Optical observation
  70. GRB070330: Correction to UVOT position
  71. GRB 070419: P60 Confirmation of Optical Afterglow
  72. GRB 070419B: Swift detection of a burst
  73. GRB 070419 optical afterglow candidate
  74. GRB 070419A: ROTSE-III Optical Limits
  75. GRB 070419: Swift detection of a burst
  76. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  77. GRB 070418: Optical and IR observations with KANATA
  78. Trigger 276045: Swift detection of a possible burst
  79. GRB 070406: Swift XRT refined analysis
  80. IBAS Alert n.4202: not a real GRB
  81. GRB 070318, SMARTS optical/IR afterglow observations
  82. GRB 070411: TLS data shows plateau, flares
  83. GRB070412: UKIRT-WFCAM JHK upper limits
  84. GRB070412: Swift UVOT observations
  85. IBAS Alert n.4199: Not a GRB
  86. GRB 070411: Swift/UVOT observations
  87. GRB 070412, Swift-BAT refined analysis
  88. GRB 070412 Liverpool Telescope optical limit
  89. GRB 070411: Optical photometry at Crni Vrh
  90. GRB 070412: Swift-XRT refined analysis
  91. GRB 070411: Swift-XRT refined analysis
  92. GRB 070412: further reanalysis of NOT images
  93. GRB 070412: Optical observations at Crni Vrh
  94. GRB 070411: OA redshift
  95. GRB 070412: Swift-XRT refined position
  96. GRB 070412: further NOT observations
  97. GRB 070412: Gemini/GMOS afterglow candidate
  98. GRB 070412: IAC80 optical afterglow candidate
  99. GRB 070411: Magellan/Clay photometry
  100. GRB 070411: Magellan/IMACS photometry

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