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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"

20529 results found.

  1. GRB050124: No Swift UVOT Detection of Afterglow Emission
  2. GRB 050124, SMARTS optical/IR observations
  3. GRB 050117a: Radio Observations
  4. GRB 050124: NIR Candidates from Keck/NIRC
  5. GRB 050124 : Lulin R-band follow-up observation
  6. GRB050124: Updated Swift XRT Position and Fluxes
  7. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  8. GRB 050123 : I-band follow-up observation
  9. GRB 050123: KAIT observations
  10. GRB050123: P60 Observations
  11. CFHTLS optical transient unlikely to be a GRB
  12. GRB050117a: Radio Observations
  13. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  14. GRB050117: Palomar WIRC Ks-band observations
  15. GRB 050117, I-band observations
  16. GRB050117: Refined XRT position
  17. GRB050117: MASTER optical observations
  18. MASTER:GRB050117 SWIFT
  19. SGR 1806-20: Further VLA Observations
  20. SGR 1806-20: Further low frequency GMRT results
  21. SGR 1806-20: Further VLA Observations
  22. SGR1806-20: Swift-BAT observations of two additional bursts
  23. Further VLA observations of SGR 1806-20
  24. Further ATCA observations of SGR 1806-20
  25. Fourth Epoch VLA observations of SGR 1806-20
  26. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  27. ATCA observations of SGR 1806-20
  28. SGR 1806-20, RHESSI observations of the 041227 giant flare
  29. Third epoch observations of SGR 1806-20 with VLA
  30. Second Epoch VLA observations of SGR 1806-20
  31. Second-epoch VLA observations of SGR 1806-20
  32. SGR1806: Detection of a Sudden Ionospheric Disturbance
  33. VLA observations of SGR 1806-20
  34. SGR1806 VLA Observations
  35. VLA observations of SGR 1806-20
  36. GRB 041217: Optical observations
  37. GRB041219, early time observations
  38. The giant outburst from SGR 1806-20
  39. GRB041228: ROTSE-III Optical Observations
  40. GRB041219; RXTE ASM Observations
  41. NIR Observations of GRB 041219
  42. GRB041226: ROTSE-III Optical Observations
  43. GRB041223: decay of the afterglow
  44. GRB041224: ROTSE-III Optical Observations
  45. GRB 041224: near-infrared observations with REM
  46. GRB041223: optical and NIR observations with REM
  47. Swift-BAT Time History of GRB041219
  48. GRB 041219: TAROT optical observations
  49. GRB 041218: TAROT optical observations
  50. GRB 041223: J-band observations of the afterglow
  51. GRB 041223: Detection of Optical Transient with LCO40
  52. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  53. GRB 041219c: PROMPT Observations
  54. GRB041223: ROTSE-III Optical Observations
  55. GRB 041218: optical observations
  56. GRB 041219: Second Epoch WSRT Radio Observations
  57. GRB 041219: WSRT Radio Afterglow Detection
  58. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  59. GRB 041218: Optical observations
  60. GRB 041219 : optical follow-up observations
  61. Deep RAPTOR observations during GRB 041219
  62. GRB 041218 Optical Observations
  63. GRB 041219 Optical Observations
  64. GRB041219: Optical Afterglow Detection
  65. GRB041219: Continued NIR Observations
  66. GRB 041219: Radio Afterglow Detection
  67. GRB 041218 : Radio Observations
  68. GRB 041218: R-band optical observations
  69. GRB041218: Liverpool Telescope optical observations
  70. GRB041218: optical observations
  71. GRB041218: Continued P60 Optical Observations
  72. GRB 041219: Infrared Afterglow Candidate
  73. GRB 041219: Infrared Afterglow Candidate
  74. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  75. GRB041219: P60 Optical Observations
  76. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  77. GRB 041217: PROMPT Observations
  78. GRB041218: optical observations
  79. GRB 041218; optical candidate
  80. GRB 041218: Optical observations
  81. GRB 041217: LCO40 Optical Observations and Possible Candidates
  82. GRB041217: Optical Observations
  83. GRB041217: NIR and optical observations with REM
  84. GRB041217: P60 Optical Observations
  85. GRB041217: Infrared Observations
  86. GRB041211: Faulkes Telescope continued optical monitoring
  87. Optical transient (GRB?) in Lynx
  88. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  89. GRB041211: Continued P60 Observations
  90. GRB041211: RAPTOR observations
  91. GRB041211, Faulkes Telescope optical observation
  92. GRB 041211: Infrared Observations
  93. GRB 041211: KAIT observations
  94. GRB 041211: Optical follow-up in East Asian region
  95. GRB970815: Discovery of Optical Afterglow
  96. GRB041015: Near-Infrared observations
  97. GRB 040924: Afterglow Color
  98. GRB 041006: GETS Optical Afterglow Observation
  99. GRB 041006: Optical Observations
  100. GRB041006, late-time optical photometry

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