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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 071020, Swift-BAT refined analysis
  2. GRB 071020A: IR Imaging with PAIRITEL
  3. GRB 071020: VLT spectroscopy
  4. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  5. GRB071020 - SDSS Pre-burst Observations
  6. GRB 071020: Swift detection of a bright burst
  7. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  8. GRB 071018: Mercator Telescope optical observations
  9. Swift autonomous slewing re-enabled
  10. GRB071010b: optical observations
  11. GRB 071018: SARA observations
  12. GRB 071018: Swift-XRT observation
  13. GRB 071017 - Swift XRT observations
  14. VLA radio observation of GRB 071018
  15. GRB071018: Correction to the GCN 6936
  16. GRB071018: Correction to the GCN 6936
  17. GRB071018: Correction to the GCN 6936
  18. GRB071018: Correction to the title of the GCN 6936
  19. GRB 071018: Possible OT from Xinglong TNT observation
  20. GRB 071010B: Light Curve Break Confirmed
  21. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  22. GRB 071018, Swift-BAT refined analysis
  23. GRB 071018?: Swift detection of a possible burst
  24. GRB 071010B: Suzaku WAM observation of the prompt emission
  25. GRB 071013: 3rd TLS Epoch - constraints on variability
  26. GRB 071013: TNT optical data refined analysis
  27. GRB 071010B: Keck/DEIMOS emission-line redshift
  28. GRB 071017: a SHORT GRB detected by INTEGRAL
  29. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  30. GRB071013: optical observations
  31. GRB 071010B: Optical observations of EST
  32. GRB 071010B: TLS 3rd Epoch - finally a break??
  33. GRB 071011: MITSuME Optical Observations
  34. GRB 070920A: deep optical observations at the NOT
  35. GRB 071010B: Photometry after 1.6 days
  36. GRB 071010B: Keck/LRIS Photometry
  37. GRB 071010B: TLS 2nd Epoch, refined analysis
  38. GRB 071013: TLS Upper Limit
  39. Correction to GCN circular no. # 6915 for GRB 071010B
  40. VLA detection of radio afterglow of GRB 071010B
  41. VLA non-detection of GRB 071011
  42. GRB 071013: Optical observations
  43. GRB 071013: optical observations at NOT
  44. GRB 071013, Swift-BAT refined analysis
  45. GRB071013: optical limit
  46. GRB071010B, BVRcIc field calibration
  47. GRB 20071013: Xinglong TNT optical Upper Limit
  48. GRB 071013: Swift detection of a burst
  49. GRB 071010C Swift-BAT detection of a burst
  50. GRB 071011: Optical Limit after 13.95hrs
  51. GRB 071011: Xinglong TNT Optical afterglow observations
  52. GRB 071010B correction to GCN 6892 optical observations
  53. GRB 071011: Swift-XRT refined analysis
  54. VLA non-detection of GRB 071010A
  55. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  56. GRB 071011, Optical afterglow
  57. GRB 071011: Confirmation of P60 optical afterglow
  58. GRB 071010B: Optical Detection
  59. GRB 071011: Kanazawa Optical limits
  60. GRB 071011: P60 Optical Afterglow Candidate
  61. GRB 071011: MARGE Optical Limits
  62. GRB 071010B: Super-LOTIS upper limit
  63. GRB 071010B optical photometry
  64. GRB 071011: XRT afterglow detection
  65. GRB 071010B: Keck/LRIS Spectroscopy
  66. GRB 071011, Swift-BAT refined analysis
  67. GRB 071010B: Gemini Spectroscopic Observations
  68. GRB 071011: Early Super-LOTIS Observations
  69. GRB 071011: NAYUTA Optical Observation
  70. GRB 071010A: Continued Keck Imaging
  71. GRB 071010B: Bright OT confirmed with TLS
  72. GRB 071011: Optical afterglow candidate
  73. GRB 071011: Swift detection of a burst
  74. Optical Observation: GRB 071010
  75. Optical observations: GRB 071010A
  76. Konus-Wind observation of GRB 071010B
  77. GRB071010B: Swift/XRT detection
  78. GRB 071010B, Swift-BAT refined analysis
  79. GRB 071010A: bright NIR afterglow
  80. GRB 071006, Swift-BAT refined analysis
  81. GRB071008: optical observations
  82. GRB 071010B possible optical transient
  83. GRB 071010A: Keck/LRIS Photometry
  84. GRB 071010B: Swift detection of a burst
  85. GRB 071010: Swift-XRT observation
  86. GRB 071008, Swift-BAT refined analysis
  87. GRB 071010, Swift-BAT refined analysis
  88. Konus-Wind observation of GRB 071006
  89. GRB071008: Swift-XRT observation
  90. GRB 071010 REM NIR observations
  91. GRB 071010: Keck/LRIS Spectroscopy
  92. GRB 071010: TAROT La Silla observatory photometry of the afterglow
  93. GRB 071010: Rapid PROMPT Detections
  94. GRB 071010: Keck Observations of the Afterglow
  95. GRB 071010: TAROT La Silla observatory detection of the afterglow
  96. GRB 071010: Swift detection of a burst
  97. GRB 071006 Swift-BAT detection of a burst
  98. GRB071008: IAC80 observation
  99. GRB 071008: Swift detection of a burst
  100. GRB 071003: XRT refined analysis

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