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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"
  1. Swift Trigger 172767 is not a GRB
  2. GRB 051215: near-infrared observations
  3. GRB051215 - SDSS pre-burst observations
  4. GRB 051215: Swift detection of a possible burst
  5. GRB 051215: A short GRB in a cluster?
  6. GRB051211B: Probable radio afterglow
  7. GRB051105: optical observations
  8. GRB 051213: Swift-BAT refined analysis
  9. GRB051211B: XRT refined analysis
  10. GRB 051211B, optical observation
  11. GRB 051213: Swift-BAT detection of a burst
  12. GRB 051211a: RTT150 optical observations
  13. GRB051211B, RBO optical observations
  14. GRB 051211A: Swift/UVOT upper limits
  15. GRB 051211B: Swift/UVOT upper limits - correction
  16. GRB 051211B: Swift/UVOT upper limits
  17. GRB 051211A,optical observation
  18. GRB 051211B: Swift XRT confirmation of the afterglow
  19. GRB051211B: Liverpool Telescope observation
  20. GRB 051211b: RTT150 optical observations
  21. GRB051211b: P60 Observations
  22. GRB 051211A and GRB051211B: BOOTES simultaneous observations
  23. GRB 051211B: Swift XRT Observations
  24. GRB 051210: Swift/UVOT upper limits
  25. GRB 051210: Magellan Imaging
  26. GRB 051211: TAROT optical limits
  27. GRB 051211B: a possible optical detection by TAROT
  28. GRB 051211B: a long GRB detected by INTEGRAL
  29. GRB 051211: Swift XRT upper limit
  30. GRB 051211:IAC80 optical observations
  31. HETE SXC localization of GRB 051211 (=H3979)
  32. GRB 051210: Optical imaging from Las Campanas
  33. GRB 051210: SALT detection limit
  34. GRB 051210: BAT further refined analysis of the short burst
  35. GRB 051210: Swift XRT refined analysis
  36. GRB 051210: FRAM early limit
  37. GRB 051210: Swift-BAT refined analysis of a short burst
  38. GRB051210: Swift UVOT Observation
  39. GRB 051210: A short GRB in a cluster?
  40. GRB 051210: Swift detection of a burst
  41. IPN observations of SGR1806-20
  42. Swift XRT positions
  43. An extraordinary long burst on December 3 from SGR1806-20
  44. IBAS Alert 2706 : not a real GRB
  45. Possible resuming of the SGR 1806-20 activity
  46. Swift UVOT Calibration Documentation
  47. GRB051117B: optical observation
  48. GRB051111: optical observaion
  49. Swift-BAT trigger 165579 is not a GRB
  50. GRB 051127: Swift-BAT detection of a possible burst
  51. GRB051117B: Swift XRT refined analysis
  52. GRB051117b: No Swift/UVOT Detection
  53. GRB051111: Rc optical observations: correction
  54. GRB 051117A: Swift/UVOT Detection of an Afterglow: Correction
  55. GRB 051117A: Swift/UVOT Detection of an Afterglow
  56. GRB051111: Suzaku WAM observation of the prompt emission
  57. GRB051111: Rc optical observations
  58. GRB051008: Suzaku WAM observation of the prompt emission
  59. GRB 051109B: GAO 150cm telescope Optical limit
  60. GRB 051109A : GAO 150cm telescope Rc-band detection
  61. GRB 051021 Optical Observations
  62. GRB 051117B: MARGE Optical Limits
  63. GRB 051117A and B: Radio Observations
  64. GRB 051117B: R and I observations of possible host galaxy
  65. GRB 051117b: NIR observations
  66. GRB 051117A: Refined analysis of the Swift-BAT burst
  67. GRB 051117B: Refined analysis of the Swift-BAT burst
  68. GRB051117A : XRT refined analysis
  69. GRB 051117B,optical observation
  70. GRB 051117B: Lulin R and I band observation
  71. GRB 051117B: Optical observations
  72. GRB 051117B: ROTSE-III Optical Limits
  73. GRB051117B: Swift XRT position
  74. GRB 051117B: Swift detection of a burst
  75. GRB 051117: Swift detection of a bright burst
  76. GRB051114: results of the Swift-XRT observation
  77. GRB 051028 Optical Observations
  78. GRB 051109B : Nainital upper limits
  79. GRB 051114: Radio Observations
  80. GRB 051114: Swift-BAT refined analysis
  81. GRB050925: analysis of the XMM-Newton observation
  82. GRB051109A optical observations
  83. GRB 051114: Swift-BAT detection of a short burst
  84. GRB 051111: Further spectroscopic analysis
  85. GRB 051111: Radio afterglow
  86. GRB 051113: Swift-BAT refined analysis
  87. GRB 051113: Swift-BAT detection of a burst
  88. GRB 051111: AEOS optical observations
  89. GRB051103: Radio Observations
  90. GRB 051109A Milagro GeV/TeV Observations
  91. GRB/SGR 050925: XMM-Newton ToO observation
  92. GRB051111: Swift/UVOT Observations
  93. GRB 051111A : R-band temporal decay index based on Lulin
  94. GRB051111: XRT preliminary analysis
  95. GRB 051111: Swift-BAT refined analysis
  96. GRB 051109A Optical Observations
  97. GRB 051111A : Lulin BVRI multi band afterglow observation
  98. GRB051111a: SARA Observations
  99. GRB 051111a: IR photometry
  100. GRB 051111: Keck HIRES redshift

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