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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 071025: ROTSE-III Refined Analysis
  2. GRB 071025: I-detection, R-dropout?
  3. GRB 071025: Swift XRT refined position
  4. GRB 071025a: PAIRITEL observations
  5. GRB071025: REM NIR afterglow
  6. GRB 071025: ROTSE-III Detection of Optical Counterpart
  7. GRB 071025: Swift detection of a burst
  8. GRB 071021: R-band detection and analysis
  9. GRB 071020: BTA spectroscopy
  10. GRB071021: Optical+NIR observations
  11. Possible radio detection of GRB 071021 with the VLA
  12. Optical observations of GRB 071020
  13. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  14. GRB 071020: SARA observations
  15. Radio detection of GRB 071020 with the VLA
  16. GRB071010b: optical observation
  17. GRB 071021: Subaru NIR observation
  18. GRB071021: MITSuME Okayama Optical Upper Limits
  19. GRB 071021: Magellan i-band observation
  20. GRB 071021: Magellan R-band observation
  21. GRB 071021: Z-band detection
  22. GRB 071021: correction to GCNC 6968
  23. GRB 071020: Fading slowly?
  24. GRB 071010B: Fading quickly
  25. GRB 071021: optical and NIR observations
  26. GRB 071021: possible high-z burst
  27. GRB 071021, Swift-BAT refined analysis
  28. GRB071018: 2nd epoch obsevations of Xinglong TNT
  29. GRB 071021: retraction of Faulkes Telescope South candidate
  30. GRB 071021: Swift-XRT Team refined analysis
  31. GRB 071021: Xinglong TNT optical Upper Limit
  32. GRB 071021 : Lulin R-band limit
  33. Konus-Wind observation of GRB 071020
  34. GRB 071021: Faulkes Telescope South optical candidate
  35. GRB 071021: Swift detection of a burst
  36. GRB 071010B: Independent Confirmation of Break
  37. GRB071020A: Xinglong TNT Optical afterglow observations
  38. GRB 071020: Swift-XRT refined analysis
  39. GRB 071020, Swift-BAT refined analysis
  40. GRB 071020A: IR Imaging with PAIRITEL
  41. GRB 071020: VLT spectroscopy
  42. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  43. GRB071020 - SDSS Pre-burst Observations
  44. GRB 071020: Swift detection of a bright burst
  45. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  46. GRB 071018: Mercator Telescope optical observations
  47. Swift autonomous slewing re-enabled
  48. GRB071010b: optical observations
  49. GRB 071018: SARA observations
  50. GRB 071018: Swift-XRT observation
  51. GRB 071017 - Swift XRT observations
  52. VLA radio observation of GRB 071018
  53. GRB071018: Correction to the GCN 6936
  54. GRB071018: Correction to the GCN 6936
  55. GRB071018: Correction to the GCN 6936
  56. GRB071018: Correction to the title of the GCN 6936
  57. GRB 071018: Possible OT from Xinglong TNT observation
  58. GRB 071010B: Light Curve Break Confirmed
  59. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  60. GRB 071018, Swift-BAT refined analysis
  61. GRB 071018?: Swift detection of a possible burst
  62. GRB 071010B: Suzaku WAM observation of the prompt emission
  63. GRB 071013: 3rd TLS Epoch - constraints on variability
  64. GRB 071013: TNT optical data refined analysis
  65. GRB 071010B: Keck/DEIMOS emission-line redshift
  66. GRB 071017: a SHORT GRB detected by INTEGRAL
  67. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  68. GRB071013: optical observations
  69. GRB 071010B: Optical observations of EST
  70. GRB 071010B: TLS 3rd Epoch - finally a break??
  71. GRB 071011: MITSuME Optical Observations
  72. GRB 070920A: deep optical observations at the NOT
  73. GRB 071010B: Photometry after 1.6 days
  74. GRB 071010B: Keck/LRIS Photometry
  75. GRB 071010B: TLS 2nd Epoch, refined analysis
  76. GRB 071013: TLS Upper Limit
  77. Correction to GCN circular no. # 6915 for GRB 071010B
  78. VLA detection of radio afterglow of GRB 071010B
  79. VLA non-detection of GRB 071011
  80. GRB 071013: Optical observations
  81. GRB 071013: optical observations at NOT
  82. GRB 071013, Swift-BAT refined analysis
  83. GRB071013: optical limit
  84. GRB071010B, BVRcIc field calibration
  85. GRB 20071013: Xinglong TNT optical Upper Limit
  86. GRB 071013: Swift detection of a burst
  87. GRB 071010C Swift-BAT detection of a burst
  88. GRB 071011: Optical Limit after 13.95hrs
  89. GRB 071011: Xinglong TNT Optical afterglow observations
  90. GRB 071010B correction to GCN 6892 optical observations
  91. GRB 071011: Swift-XRT refined analysis
  92. VLA non-detection of GRB 071010A
  93. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  94. GRB 071011, Optical afterglow
  95. GRB 071011: Confirmation of P60 optical afterglow
  96. GRB 071010B: Optical Detection
  97. GRB 071011: Kanazawa Optical limits
  98. GRB 071011: P60 Optical Afterglow Candidate
  99. GRB 071011: MARGE Optical Limits
  100. GRB 071010B: Super-LOTIS upper limit

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