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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"

28039 results found.

  1. GRB 071020: SARA observations
  2. Radio detection of GRB 071020 with the VLA
  3. GRB071021: MITSuME Okayama Optical Upper Limits
  4. GRB 071021: Z-band detection
  5. GRB 071021: optical and NIR observations
  6. GRB 071021: possible high-z burst
  7. GRB 071021, Swift-BAT refined analysis
  8. GRB071018: 2nd epoch obsevations of Xinglong TNT
  9. GRB 071021: Swift-XRT Team refined analysis
  10. GRB 071021: Xinglong TNT optical Upper Limit
  11. GRB 071021 : Lulin R-band limit
  12. GRB 071021: Swift detection of a burst
  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: ROTSE-III Analysis of Optical Counterpart
  18. GRB071020 - SDSS Pre-burst Observations
  19. GRB 071020: Swift detection of a bright burst
  20. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  21. GRB 071018: Mercator Telescope optical observations
  22. Swift autonomous slewing re-enabled
  23. GRB 071018: SARA observations
  24. GRB 071018: Swift-XRT observation
  25. GRB 071017 - Swift XRT observations
  26. GRB 071018: Possible OT from Xinglong TNT observation
  27. GRB 071010B: Light Curve Break Confirmed
  28. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  29. GRB 071018, Swift-BAT refined analysis
  30. GRB 071010B: Suzaku WAM observation of the prompt emission
  31. GRB 071013: 3rd TLS Epoch - constraints on variability
  32. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  33. GRB 071010B: Optical observations of EST
  34. GRB 071011: MITSuME Optical Observations
  35. GRB 070920A: deep optical observations at the NOT
  36. GRB 071010B: Keck/LRIS Photometry
  37. GRB 071013: TLS Upper Limit
  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. GRB071010B, BVRcIc field calibration
  43. GRB 20071013: Xinglong TNT optical Upper Limit
  44. GRB 071010C Swift-BAT detection of a burst
  45. GRB 071011: Optical Limit after 13.95hrs
  46. GRB 071010B correction to GCN 6892 optical observations
  47. GRB 071011: Swift-XRT refined analysis
  48. VLA non-detection of GRB 071010A
  49. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  50. GRB 071011: Confirmation of P60 optical afterglow
  51. GRB 071010B: Optical Detection
  52. GRB 071011: Kanazawa Optical limits
  53. GRB 071011: P60 Optical Afterglow Candidate
  54. GRB 071011: MARGE Optical Limits
  55. GRB 071010B: Super-LOTIS upper limit
  56. GRB 071010B optical photometry
  57. GRB 071011: XRT afterglow detection
  58. GRB 071011, Swift-BAT refined analysis
  59. GRB 071010B: Gemini Spectroscopic Observations
  60. GRB 071011: NAYUTA Optical Observation
  61. GRB 071010A: Continued Keck Imaging
  62. GRB 071010B: Bright OT confirmed with TLS
  63. GRB 071011: Swift detection of a burst
  64. Optical Observation: GRB 071010
  65. Optical observations: GRB 071010A
  66. Konus-Wind observation of GRB 071010B
  67. GRB071010B: Swift/XRT detection
  68. GRB 071010B, Swift-BAT refined analysis
  69. GRB 071010A: bright NIR afterglow
  70. GRB 071006, Swift-BAT refined analysis
  71. GRB 071010A: Keck/LRIS Photometry
  72. GRB 071008, Swift-BAT refined analysis
  73. GRB 071010, Swift-BAT refined analysis
  74. GRB 071010 REM NIR observations
  75. GRB 071010: TAROT La Silla observatory detection of the afterglow
  76. GRB 071008: Swift detection of a burst
  77. GRB 071003: XRT refined analysis
  78. GRB070920A: MAGIC telescope GeV observation
  79. Radio detection of GRB 071003 with the VLA
  80. GRB 070810B: further XRT analysis
  81. GRB 071003: Possible rebrightening
  82. GRB 071003 : Lulin R-band observations
  83. GRB 071003: Keck HIRES spectroscopy
  84. GRB 071003, Swift-BAT refined analysis
  85. GRB 071003: P60 Confirmation of Optical Afterglow
  86. GRB 071001: Swift-XRT Team refined analysis
  87. GRB 071001, Swift-BAT refined analysis
  88. Faulkes Telescope South observations of GRB 071001
  89. GRB 071001: Swift detection of a burst
  90. VLA observation of GRB 070923
  91. GRB 070911, SMARTS optical/IR afterglow observations
  92. GRB 070925: Gemini South Imaging
  93. GRB070925: Swift-XRT Position
  94. GRB 070920B: ROTSE-III Early Optical Limits
  95. GRB 070925: a long GRB detected by INTEGRAL
  96. GRB 070923, Swift-BAT refined analysis
  97. GRB 070920B: XRT observations
  98. GRB 070917: Suzaku/WAM observation of the prompt emission
  99. GRB 070920B: TAROT La Silla observatory optical observations
  100. GRB 070920B, Swift-BAT refined analysis

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