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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 071018, Swift-BAT refined analysis
  2. GRB 071018?: Swift detection of a possible burst
  3. GRB 071010B: Suzaku WAM observation of the prompt emission
  4. GRB 071013: 3rd TLS Epoch - constraints on variability
  5. GRB 071013: TNT optical data refined analysis
  6. GRB 071010B: Keck/DEIMOS emission-line redshift
  7. GRB 071017: a SHORT GRB detected by INTEGRAL
  8. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  9. GRB071013: optical observations
  10. GRB 071010B: Optical observations of EST
  11. GRB 071010B: TLS 3rd Epoch - finally a break??
  12. GRB 071011: MITSuME Optical Observations
  13. GRB 070920A: deep optical observations at the NOT
  14. GRB 071010B: Photometry after 1.6 days
  15. GRB 071010B: Keck/LRIS Photometry
  16. GRB 071010B: TLS 2nd Epoch, refined analysis
  17. GRB 071013: TLS Upper Limit
  18. Correction to GCN circular no. # 6915 for GRB 071010B
  19. VLA detection of radio afterglow of GRB 071010B
  20. VLA non-detection of GRB 071011
  21. GRB 071013: Optical observations
  22. GRB 071013: optical observations at NOT
  23. GRB 071013, Swift-BAT refined analysis
  24. GRB071013: optical limit
  25. GRB071010B, BVRcIc field calibration
  26. GRB 20071013: Xinglong TNT optical Upper Limit
  27. GRB 071013: Swift detection of a burst
  28. GRB 071010C Swift-BAT detection of a burst
  29. GRB 071011: Optical Limit after 13.95hrs
  30. GRB 071011: Xinglong TNT Optical afterglow observations
  31. GRB 071010B correction to GCN 6892 optical observations
  32. GRB 071011: Swift-XRT refined analysis
  33. VLA non-detection of GRB 071010A
  34. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  35. GRB 071011, Optical afterglow
  36. GRB 071011: Confirmation of P60 optical afterglow
  37. GRB 071010B: Optical Detection
  38. GRB 071011: Kanazawa Optical limits
  39. GRB 071011: P60 Optical Afterglow Candidate
  40. GRB 071011: MARGE Optical Limits
  41. GRB 071010B: Super-LOTIS upper limit
  42. GRB 071010B optical photometry
  43. GRB 071011: XRT afterglow detection
  44. GRB 071010B: Keck/LRIS Spectroscopy
  45. GRB 071011, Swift-BAT refined analysis
  46. GRB 071010B: Gemini Spectroscopic Observations
  47. GRB 071011: Early Super-LOTIS Observations
  48. GRB 071011: NAYUTA Optical Observation
  49. GRB 071010A: Continued Keck Imaging
  50. GRB 071010B: Bright OT confirmed with TLS
  51. GRB 071011: Optical afterglow candidate
  52. GRB 071011: Swift detection of a burst
  53. Optical Observation: GRB 071010
  54. Optical observations: GRB 071010A
  55. Konus-Wind observation of GRB 071010B
  56. GRB071010B: Swift/XRT detection
  57. GRB 071010B, Swift-BAT refined analysis
  58. GRB 071010A: bright NIR afterglow
  59. GRB 071006, Swift-BAT refined analysis
  60. GRB071008: optical observations
  61. GRB 071010B possible optical transient
  62. GRB 071010A: Keck/LRIS Photometry
  63. GRB 071010B: Swift detection of a burst
  64. GRB 071010: Swift-XRT observation
  65. GRB 071008, Swift-BAT refined analysis
  66. GRB 071010, Swift-BAT refined analysis
  67. Konus-Wind observation of GRB 071006
  68. GRB071008: Swift-XRT observation
  69. GRB 071010 REM NIR observations
  70. GRB 071010: Keck/LRIS Spectroscopy
  71. GRB 071010: TAROT La Silla observatory photometry of the afterglow
  72. GRB 071010: Rapid PROMPT Detections
  73. GRB 071010: Keck Observations of the Afterglow
  74. GRB 071010: TAROT La Silla observatory detection of the afterglow
  75. GRB 071010: Swift detection of a burst
  76. GRB 071006 Swift-BAT detection of a burst
  77. GRB071008: IAC80 observation
  78. GRB 071008: Swift detection of a burst
  79. GRB 071003: XRT refined analysis
  80. GRB070920A: MAGIC telescope GeV observation
  81. Radio detection of GRB 071003 with the VLA
  82. GRB 070810B: further XRT analysis
  83. GRB 071003: VLT spectroscopy
  84. GRB 071003: Keck spectroscopy
  85. Konus-Wind observation of GRB 071003
  86. GRB071003: Faulkes Telescope North observations
  87. GRB 071003: Possible rebrightening
  88. GRB 071003 : Lulin R-band observations
  89. GRB 071003: Swift XRT position
  90. GRB 071003: OA power-law decay indices from KAIT
  91. GRB 071003: Keck HIRES spectroscopy
  92. GRB 071003, Swift-BAT refined analysis
  93. GRB 071003: MARGE Observations
  94. GRB 071003 Optical observations
  95. GRB 071003: P60 Confirmation of Optical Afterglow
  96. GRB 071003: KAIT optical afterglow observations
  97. GRB 071003: Swift detection of a bright burst
  98. GRB 070714B: host galaxy spectroscopic redshift
  99. GRB 071001: Swift-XRT Team refined analysis
  100. GRB 071001, Swift-BAT refined analysis

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