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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"

19531 results found.

  1. No radio detection at Swift-XRT position
  2. GRB 071109: Swift-XRT possible X-ray counterpart
  3. GRB 071104: Swift-XRT Team Refined Analysis
  4. GRB 071104: Possible Swift UVOT Afterglow Candidate
  5. GRB 071104: Swift-XRT position
  6. Swift XRT and UVOT observations of GRB071028B
  7. GRB 071101, Swift-BAT refined analysis
  8. GRB 071101: Swift-XRT Team refined analysis
  9. GRB 071101: TAROT Calern observatory optical observations
  10. GRB 071101: Swift XRT position
  11. GRB 071101: BOOTES-2 prompt optical observations
  12. GRB 071101: a nearby galaxy
  13. GRB 071101: Swift detection of a burst
  14. GRB 071031, Swift-BAT refined analysis
  15. GRB 071031: Swift/UVOT detection of afterglow
  16. GRB 071031: Swift-XRT Team refined analysis
  17. GRB 071031: Swift detection of a burst with an optical counterpart
  18. GRB 071028B Swift-BAT detection of a burst
  19. Swift UVOT upper limits to GRB071028
  20. GRB 071028: Swift-XRT Team refined analysis
  21. GRB 071028, Swift-BAT refined analysis
  22. GRB 071028: Swift detection of a burst
  23. GRB 071025: Kuiper Telescope Optical Observations
  24. GRB 071018: Revised BAT position
  25. GRB 071025A: RAPTOR Observations of Complex Early Optical Behavior
  26. GRB071021: MARGE Optical Limits
  27. GRB071020, optical upper limit
  28. GRB 071025 Milagro GeV/TeV Observations
  29. Swift UVOT upper limits
  30. GRB 071025: Swift-XRT Team refined analysis
  31. GRB 071025, Swift-BAT refined analysis
  32. GRB 071025: Early Super-LOTIS Observations
  33. GRB 071025: ROTSE-III Refined Analysis
  34. GRB 071025: Swift XRT refined position
  35. GRB 071025: ROTSE-III Detection of Optical Counterpart
  36. GRB 071025: Swift detection of a burst
  37. GRB 071020: BTA spectroscopy
  38. Possible radio detection of GRB 071021 with the VLA
  39. Radio detection of GRB 071020 with the VLA
  40. GRB 071021: optical and NIR observations
  41. GRB 071021, Swift-BAT refined analysis
  42. GRB 071021: Swift-XRT Team refined analysis
  43. Konus-Wind observation of GRB 071020
  44. GRB 071021: Swift detection of a burst
  45. GRB 071020: Swift-XRT refined analysis
  46. GRB 071020, Swift-BAT refined analysis
  47. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  48. GRB071020 - SDSS Pre-burst Observations
  49. GRB 071020: Swift detection of a bright burst
  50. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  51. GRB 071018: Mercator Telescope optical observations
  52. Swift autonomous slewing re-enabled
  53. GRB 071018: Swift-XRT observation
  54. GRB 071017 - Swift XRT observations
  55. VLA radio observation of GRB 071018
  56. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  57. GRB 071018, Swift-BAT refined analysis
  58. GRB 071018?: Swift detection of a possible burst
  59. GRB 071010B: Suzaku WAM observation of the prompt emission
  60. GRB 071013: 3rd TLS Epoch - constraints on variability
  61. GRB 071013: TLS Upper Limit
  62. VLA detection of radio afterglow of GRB 071010B
  63. VLA non-detection of GRB 071011
  64. GRB 071013: Optical observations
  65. GRB 071013, Swift-BAT refined analysis
  66. GRB 071013: Swift detection of a burst
  67. GRB 071010C Swift-BAT detection of a burst
  68. GRB 071011: Swift-XRT refined analysis
  69. VLA non-detection of GRB 071010A
  70. GRB 071011, Optical afterglow
  71. GRB 071011: MARGE Optical Limits
  72. GRB 071011: XRT afterglow detection
  73. GRB 071011, Swift-BAT refined analysis
  74. GRB 071011: Early Super-LOTIS Observations
  75. GRB 071010B: Bright OT confirmed with TLS
  76. GRB 071011: Swift detection of a burst
  77. Optical Observation: GRB 071010
  78. Optical observations: GRB 071010A
  79. Konus-Wind observation of GRB 071010B
  80. GRB071010B: Swift/XRT detection
  81. GRB 071010B, Swift-BAT refined analysis
  82. GRB 071006, Swift-BAT refined analysis
  83. GRB 071010B: Swift detection of a burst
  84. GRB 071010: Swift-XRT observation
  85. GRB 071008, Swift-BAT refined analysis
  86. GRB 071010, Swift-BAT refined analysis
  87. GRB071008: Swift-XRT observation
  88. GRB 071010: TAROT La Silla observatory detection of the afterglow
  89. GRB 071010: Swift detection of a burst
  90. GRB 071006 Swift-BAT detection of a burst
  91. GRB071008: IAC80 observation
  92. GRB 071008: Swift detection of a burst
  93. GRB 071003: XRT refined analysis
  94. GRB070920A: MAGIC telescope GeV observation
  95. Radio detection of GRB 071003 with the VLA
  96. GRB 070810B: further XRT analysis
  97. Konus-Wind observation of GRB 071003
  98. GRB 071003: Swift XRT position
  99. GRB 071003, Swift-BAT refined analysis
  100. GRB 071003: MARGE Observations

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