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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"

20556 results found.

  1. GRB 050219b: candidate NIR afterglow
  2. GRB 050223: optical observations
  3. GRB050223: No Swift UVOT Detection of Afterglow Emission
  4. GRB050223: ROTSE-III Optical Observations
  5. GRB 050223: Swift XRT Position
  6. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  7. GRB050219b: CORRECTION to time of UVOT observations
  8. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  9. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  10. GRB 050219a: Optical observations from LCO
  11. GRB 050219b: Optical and near-IR observations from LCO
  12. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  13. GRB 050219b: CORRECTION: Swift XRT Position
  14. GRB 050219b: Swift XRT Position
  15. GRB 050219a, optical observations
  16. GRB 050219a: Refined XRT position
  17. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  18. GRB050215b: Swift UVOT Detection of Afterglow Emission
  19. GRB 050215B: Radio Observations
  20. GRB 050215b: XRT confirmation of IR afterglow candidate
  21. GRB050215b: P60 Optical Observations
  22. GRB 050215b: Swift XRT Source Variability
  23. GRB 050215b : Lulin follow-up observation
  24. GRB 050215b, BOOTES-2 simultaneous optical observations
  25. GRB 050215b: Swift XRT Observations
  26. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  27. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  28. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  29. GRB050215B: ROTSE-III optical observations
  30. GRB050215A: ROTSE-III Optical Observations
  31. GRB050209: TAROT optical observations
  32. short/hard GRB 050202, optical observations
  33. GRB050209: REM optical observations
  34. GRB 050209 Optical observations
  35. GRB050209: P60 Optical Observations
  36. GRB 050128: Radio observations
  37. GRB 050202: Second epoch radio observations
  38. GRB 050129: Optical observations
  39. GRB050202: Radio Observations
  40. GRB 050202: Optical observations with LCO40
  41. GRB 050128 Optical observation with REM
  42. GRB050128: Faulkes Telescope South observations
  43. GRB 050124: Radio Observations
  44. GRB 050128: near-infrared observations with REM
  45. GRB050128,optical observations
  46. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  47. GRB 050126: Radio Observations
  48. GRB050128 Swift-BAT observations
  49. GRB 050128: Swift XRT prompt afterglow position
  50. HETE #3667: P60 Observations
  51. GRB 050124: K-band afterglow observations
  52. GRB050126: MASTER optical observations
  53. GRB 050126: Prompt XRT detection and localization
  54. GRB050124: No Swift UVOT Detection of Afterglow Emission
  55. GRB 050124, SMARTS optical/IR observations
  56. GRB 050117a: Radio Observations
  57. GRB 050124: NIR Candidates from Keck/NIRC
  58. GRB 050124 : Lulin R-band follow-up observation
  59. GRB050124: Updated Swift XRT Position and Fluxes
  60. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  61. GRB 050123 : I-band follow-up observation
  62. GRB 050123: KAIT observations
  63. GRB050123: P60 Observations
  64. CFHTLS optical transient unlikely to be a GRB
  65. GRB050117a: Radio Observations
  66. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  67. GRB050117: Palomar WIRC Ks-band observations
  68. GRB 050117, I-band observations
  69. GRB050117: Refined XRT position
  70. GRB050117: MASTER optical observations
  71. MASTER:GRB050117 SWIFT
  72. SGR 1806-20: Further VLA Observations
  73. SGR 1806-20: Further low frequency GMRT results
  74. SGR 1806-20: Further VLA Observations
  75. SGR1806-20: Swift-BAT observations of two additional bursts
  76. Further VLA observations of SGR 1806-20
  77. Further ATCA observations of SGR 1806-20
  78. Fourth Epoch VLA observations of SGR 1806-20
  79. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  80. ATCA observations of SGR 1806-20
  81. SGR 1806-20, RHESSI observations of the 041227 giant flare
  82. Third epoch observations of SGR 1806-20 with VLA
  83. Second Epoch VLA observations of SGR 1806-20
  84. Second-epoch VLA observations of SGR 1806-20
  85. SGR1806: Detection of a Sudden Ionospheric Disturbance
  86. VLA observations of SGR 1806-20
  87. SGR1806 VLA Observations
  88. VLA observations of SGR 1806-20
  89. GRB 041217: Optical observations
  90. GRB041219, early time observations
  91. The giant outburst from SGR 1806-20
  92. GRB041228: ROTSE-III Optical Observations
  93. GRB041219; RXTE ASM Observations
  94. NIR Observations of GRB 041219
  95. GRB041226: ROTSE-III Optical Observations
  96. GRB041223: decay of the afterglow
  97. GRB041224: ROTSE-III Optical Observations
  98. GRB 041224: near-infrared observations with REM
  99. GRB041223: optical and NIR observations with REM
  100. Swift-BAT Time History of GRB041219

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