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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"

32508 results found.

  1. GRB070506: Swift XRT refined analysis
  2. GRB 070506, Swift-BAT Refined Analysis
  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 070429B: Swift XRT refined analysis
  17. GRB 070429B: ROTSE-III Optical Limits
  18. GRB 070429: ROTSE-III Optical Limits
  19. GRB 070427, Swift-BAT Refined Analysis
  20. LT monitoring of GRB070412
  21. GRB 070411, further deep LBT photometry
  22. GRB 070411: Late-time Keck imaging
  23. GRB070419B: Suzaku WAM observation of the prompt emission
  24. GRB 070420, SMARTS optical/IR afterglow observations
  25. GRB 070411, deep LBT photometry
  26. Konus-Wind observation of GRB 070420
  27. GRB 070411: break in the optical light curve
  28. GRB 070420 Swift-BAT Refined Analysis
  29. GRB070419A: Kuiper Optical detection
  30. GRB070419a: Swift UVOT observations
  31. GRB 070419A: MARGE Observations
  32. GRB 070420: optical rebrightening observed at Mt. John
  33. GRB 070420: Swift XRT refined analysis
  34. GRB070420: Swift UVOT continuing observations
  35. GRB 070411: BART early limit
  36. GRB 070420: Faulkes Telescope South Observations
  37. GBR 070419A: Swift/XRT refined analysis
  38. GRB 070420: NIR and optical afterglow confirmed
  39. GRB 070419A: MITSuME Okayama Observations
  40. GRB 070419A: Early Super-LOTIS Observations
  41. GRB 070419B, Swift-BAT refined analysis
  42. GRB 070419A Swift-BAT Refined Analysis
  43. GRB070419B: Confirmation of Optical Transient
  44. GRB 070419A: RAPTOR Detection of Early Emission
  45. GRB 070419B: Swift XRT refined analysis
  46. GRB 070419: Keck/LRIS Absorption Redshift
  47. GRB 070419A, Optical observations
  48. GRB 070411: Deep VLT detection
  49. GRB 070419A: SARA observations
  50. GRB 070419A: NAYUTA Optical Observation
  51. GRB 070419A: Faulkes Telescope North Optical Observations
  52. GRB 070419B optical afterglow candidate
  53. GRB 070419A: Optical and IR observations with KANATA
  54. GRB 070419B: optical afterglow candidate
  55. GRB070419A, optical observation
  56. Infrared detection of GRB070419A with UKIRT
  57. GRB070330: Correction to UVOT position
  58. GRB 070419: P60 Confirmation of Optical Afterglow
  59. GRB 070419 optical afterglow candidate
  60. GRB 070419A: ROTSE-III Optical Limits
  61. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  62. GRB 070418: Optical and IR observations with KANATA
  63. GRB 070406: Swift XRT refined analysis
  64. GRB 070318, SMARTS optical/IR afterglow observations
  65. GRB 070411: TLS data shows plateau, flares
  66. GRB070412: Swift UVOT observations
  67. GRB 070411: Swift/UVOT observations
  68. GRB 070412, Swift-BAT refined analysis
  69. GRB 070412 Liverpool Telescope optical limit
  70. GRB 070411: Optical photometry at Crni Vrh
  71. GRB 070412: Swift-XRT refined analysis
  72. GRB 070411: Swift-XRT refined analysis
  73. GRB 070412: further reanalysis of NOT images
  74. GRB 070412: Optical observations at Crni Vrh
  75. GRB 070411: OA redshift
  76. GRB 070412: Swift-XRT refined position
  77. GRB 070412: further NOT observations
  78. GRB 070412: Gemini/GMOS afterglow candidate
  79. GRB 070412: IAC80 optical afterglow candidate
  80. GRB 070412: NOT observations
  81. GRB 070412: Nearby bright galaxy
  82. GRB 070411, Swift-BAT refined analysis
  83. GRB 070411 : Liverpool Telescope Observations
  84. GRB 070411: Optical observations at Crni Vrh
  85. GRB 070411: ROTSE-III Detection of Optical Counterpart
  86. GRB 070411: Tautenburg RRM Afterglow Confirmation
  87. GRB 070406: "Star" in XRT error circle S2 is an AGN?
  88. GRB 070406: Swift XRT team further analysis
  89. Suzaku ToO observation of SGR 1806-20
  90. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  91. GRB 070406, Swift-BAT refined analysis
  92. GRB 070406: Gemini South Imaging and XRT analysis
  93. GRB070406: Swift UVOT observations
  94. GRB 070406: further analysis of NOT images.
  95. Short GRB 070406 - Possible Bright Host Galaxy
  96. GRB 070406: Swift XRT Team analysis - Possible X-ray counterpart
  97. GRB 070406: NOT observations
  98. GRB 070406: Optical candidate
  99. GRB 070406: photo-z of a bright galaxy in BAT error circle
  100. GRB 070402: Suzaku WAM observation of the prompt emission

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