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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 071021: optical and NIR observations
  2. GRB 071021: possible high-z burst
  3. GRB 071021, Swift-BAT refined analysis
  4. GRB071018: 2nd epoch obsevations of Xinglong TNT
  5. GRB 071021: retraction of Faulkes Telescope South candidate
  6. GRB 071021: Swift-XRT Team refined analysis
  7. GRB 071021: Xinglong TNT optical Upper Limit
  8. GRB 071021 : Lulin R-band limit
  9. Konus-Wind observation of GRB 071020
  10. GRB 071021: Faulkes Telescope South optical candidate
  11. GRB 071021: Swift detection of a burst
  12. GRB 071010B: Independent Confirmation of Break
  13. GRB071020A: Xinglong TNT Optical afterglow observations
  14. GRB 071020: Swift-XRT refined analysis
  15. GRB 071020, Swift-BAT refined analysis
  16. GRB 071020A: IR Imaging with PAIRITEL
  17. GRB 071020: VLT spectroscopy
  18. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  19. GRB071020 - SDSS Pre-burst Observations
  20. GRB 071020: Swift detection of a bright burst
  21. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  22. GRB 071018: Mercator Telescope optical observations
  23. Swift autonomous slewing re-enabled
  24. GRB071010b: optical observations
  25. GRB 071018: SARA observations
  26. GRB 071018: Swift-XRT observation
  27. GRB 071017 - Swift XRT observations
  28. VLA radio observation of GRB 071018
  29. GRB071018: Correction to the GCN 6936
  30. GRB071018: Correction to the GCN 6936
  31. GRB071018: Correction to the GCN 6936
  32. GRB071018: Correction to the title of the GCN 6936
  33. GRB 071018: Possible OT from Xinglong TNT observation
  34. GRB 071010B: Light Curve Break Confirmed
  35. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  36. GRB 071018, Swift-BAT refined analysis
  37. GRB 071018?: Swift detection of a possible burst
  38. GRB 071010B: Suzaku WAM observation of the prompt emission
  39. GRB 071013: 3rd TLS Epoch - constraints on variability
  40. GRB 071013: TNT optical data refined analysis
  41. GRB 071010B: Keck/DEIMOS emission-line redshift
  42. GRB 071017: a SHORT GRB detected by INTEGRAL
  43. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  44. GRB071013: optical observations
  45. GRB 071010B: Optical observations of EST
  46. GRB 071010B: TLS 3rd Epoch - finally a break??
  47. GRB 071011: MITSuME Optical Observations
  48. GRB 070920A: deep optical observations at the NOT
  49. GRB 071010B: Photometry after 1.6 days
  50. GRB 071010B: Keck/LRIS Photometry
  51. GRB 071010B: TLS 2nd Epoch, refined analysis
  52. GRB 071013: TLS Upper Limit
  53. Correction to GCN circular no. # 6915 for GRB 071010B
  54. VLA detection of radio afterglow of GRB 071010B
  55. VLA non-detection of GRB 071011
  56. GRB 071013: Optical observations
  57. GRB 071013: optical observations at NOT
  58. GRB 071013, Swift-BAT refined analysis
  59. GRB071013: optical limit
  60. GRB071010B, BVRcIc field calibration
  61. GRB 20071013: Xinglong TNT optical Upper Limit
  62. GRB 071013: Swift detection of a burst
  63. GRB 071010C Swift-BAT detection of a burst
  64. GRB 071011: Optical Limit after 13.95hrs
  65. GRB 071011: Xinglong TNT Optical afterglow observations
  66. GRB 071010B correction to GCN 6892 optical observations
  67. GRB 071011: Swift-XRT refined analysis
  68. VLA non-detection of GRB 071010A
  69. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  70. GRB 071011, Optical afterglow
  71. GRB 071011: Confirmation of P60 optical afterglow
  72. GRB 071010B: Optical Detection
  73. GRB 071011: Kanazawa Optical limits
  74. GRB 071011: P60 Optical Afterglow Candidate
  75. GRB 071011: MARGE Optical Limits
  76. GRB 071010B: Super-LOTIS upper limit
  77. GRB 071010B optical photometry
  78. GRB 071011: XRT afterglow detection
  79. GRB 071010B: Keck/LRIS Spectroscopy
  80. GRB 071011, Swift-BAT refined analysis
  81. GRB 071010B: Gemini Spectroscopic Observations
  82. GRB 071011: Early Super-LOTIS Observations
  83. GRB 071011: NAYUTA Optical Observation
  84. GRB 071010A: Continued Keck Imaging
  85. GRB 071010B: Bright OT confirmed with TLS
  86. GRB 071011: Optical afterglow candidate
  87. GRB 071011: Swift detection of a burst
  88. Optical Observation: GRB 071010
  89. Optical observations: GRB 071010A
  90. Konus-Wind observation of GRB 071010B
  91. GRB071010B: Swift/XRT detection
  92. GRB 071010B, Swift-BAT refined analysis
  93. GRB 071010A: bright NIR afterglow
  94. GRB 071006, Swift-BAT refined analysis
  95. GRB071008: optical observations
  96. GRB 071010B possible optical transient
  97. GRB 071010A: Keck/LRIS Photometry
  98. GRB 071010B: Swift detection of a burst
  99. GRB 071010: Swift-XRT observation
  100. GRB 071008, Swift-BAT refined analysis

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