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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"

20559 results found.

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

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