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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: ROTSE-III Analysis of Optical Counterpart
  2. GRB071020 - SDSS Pre-burst Observations
  3. GRB 071020: Swift detection of a bright burst
  4. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  5. GRB 071018: Mercator Telescope optical observations
  6. Swift autonomous slewing re-enabled
  7. GRB071010b: optical observations
  8. GRB 071018: SARA observations
  9. GRB 071018: Swift-XRT observation
  10. GRB 071017 - Swift XRT observations
  11. VLA radio observation of GRB 071018
  12. GRB071018: Correction to the GCN 6936
  13. GRB071018: Correction to the GCN 6936
  14. GRB071018: Correction to the GCN 6936
  15. GRB071018: Correction to the title of the GCN 6936
  16. GRB 071018: Possible OT from Xinglong TNT observation
  17. GRB 071010B: Light Curve Break Confirmed
  18. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  19. GRB 071018, Swift-BAT refined analysis
  20. GRB 071018?: Swift detection of a possible burst
  21. GRB 071010B: Suzaku WAM observation of the prompt emission
  22. GRB 071013: 3rd TLS Epoch - constraints on variability
  23. GRB 071013: TNT optical data refined analysis
  24. GRB 071010B: Keck/DEIMOS emission-line redshift
  25. GRB 071017: a SHORT GRB detected by INTEGRAL
  26. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  27. GRB071013: optical observations
  28. GRB 071010B: Optical observations of EST
  29. GRB 071010B: TLS 3rd Epoch - finally a break??
  30. GRB 071011: MITSuME Optical Observations
  31. GRB 070920A: deep optical observations at the NOT
  32. GRB 071010B: Photometry after 1.6 days
  33. GRB 071010B: Keck/LRIS Photometry
  34. GRB 071010B: TLS 2nd Epoch, refined analysis
  35. GRB 071013: TLS Upper Limit
  36. Correction to GCN circular no. # 6915 for GRB 071010B
  37. VLA detection of radio afterglow of GRB 071010B
  38. VLA non-detection of GRB 071011
  39. GRB 071013: Optical observations
  40. GRB 071013: optical observations at NOT
  41. GRB 071013, Swift-BAT refined analysis
  42. GRB071013: optical limit
  43. GRB071010B, BVRcIc field calibration
  44. GRB 20071013: Xinglong TNT optical Upper Limit
  45. GRB 071013: Swift detection of a burst
  46. GRB 071010C Swift-BAT detection of a burst
  47. GRB 071011: Optical Limit after 13.95hrs
  48. GRB 071011: Xinglong TNT Optical afterglow observations
  49. GRB 071010B correction to GCN 6892 optical observations
  50. GRB 071011: Swift-XRT refined analysis
  51. VLA non-detection of GRB 071010A
  52. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  53. GRB 071011, Optical afterglow
  54. GRB 071011: Confirmation of P60 optical afterglow
  55. GRB 071010B: Optical Detection
  56. GRB 071011: Kanazawa Optical limits
  57. GRB 071011: P60 Optical Afterglow Candidate
  58. GRB 071011: MARGE Optical Limits
  59. GRB 071010B: Super-LOTIS upper limit
  60. GRB 071010B optical photometry
  61. GRB 071011: XRT afterglow detection
  62. GRB 071010B: Keck/LRIS Spectroscopy
  63. GRB 071011, Swift-BAT refined analysis
  64. GRB 071010B: Gemini Spectroscopic Observations
  65. GRB 071011: Early Super-LOTIS Observations
  66. GRB 071011: NAYUTA Optical Observation
  67. GRB 071010A: Continued Keck Imaging
  68. GRB 071010B: Bright OT confirmed with TLS
  69. GRB 071011: Optical afterglow candidate
  70. GRB 071011: Swift detection of a burst
  71. Optical Observation: GRB 071010
  72. Optical observations: GRB 071010A
  73. Konus-Wind observation of GRB 071010B
  74. GRB071010B: Swift/XRT detection
  75. GRB 071010B, Swift-BAT refined analysis
  76. GRB 071010A: bright NIR afterglow
  77. GRB 071006, Swift-BAT refined analysis
  78. GRB071008: optical observations
  79. GRB 071010B possible optical transient
  80. GRB 071010A: Keck/LRIS Photometry
  81. GRB 071010B: Swift detection of a burst
  82. GRB 071010: Swift-XRT observation
  83. GRB 071008, Swift-BAT refined analysis
  84. GRB 071010, Swift-BAT refined analysis
  85. Konus-Wind observation of GRB 071006
  86. GRB071008: Swift-XRT observation
  87. GRB 071010 REM NIR observations
  88. GRB 071010: Keck/LRIS Spectroscopy
  89. GRB 071010: TAROT La Silla observatory photometry of the afterglow
  90. GRB 071010: Rapid PROMPT Detections
  91. GRB 071010: Keck Observations of the Afterglow
  92. GRB 071010: TAROT La Silla observatory detection of the afterglow
  93. GRB 071010: Swift detection of a burst
  94. GRB 071006 Swift-BAT detection of a burst
  95. GRB071008: IAC80 observation
  96. GRB 071008: Swift detection of a burst
  97. GRB 071003: XRT refined analysis
  98. GRB070920A: MAGIC telescope GeV observation
  99. Radio detection of GRB 071003 with the VLA
  100. GRB 070810B: further XRT analysis

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