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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"

28042 results found.

  1. GRB 090621B: P60 Observations
  2. GRB 090621B: VLA observations
  3. GRB 090620: Fermi GBM detecion
  4. GRB 090621B: Swift/UVOT Upper Limits
  5. GRB 090621B: Swift-BAT refined analysis
  6. GRB 090621B: Swift-XRT refined analysis
  7. GRB 090621B: RTT150 optical observations
  8. GRB 090621B: Swift detection of a short hard burst
  9. GRB 090621: Swift/UVOT Upper Limits
  10. GRB 090621: Swift-XRT Team refined analysis
  11. GRB090618: Spectrum and photometry from 6.0m BTA
  12. GRB 090621: Swift detection of a burst
  13. GRB090618, underlying supernova search
  14. GRB090618: OAA-OAUV Optical observations
  15. GRB 090618: Fermi GBM observation
  16. GRB 090618, Swift-BAT refined spectral analysis
  17. VLA radio detection of GRB 090618
  18. GRB 090618 15GHz radio detection
  19. GRB090618 - Continued optical monitoring and light curve break
  20. GRB 090618: Swift-BAT refined analysis
  21. GRB 090618: SARA observations
  22. GRB090618: Swift-XRT team refined analysis
  23. GRB090618: Swift/UVOT bright afterglow detection
  24. GRB 090618: SDSS host detection
  25. Swift XRT observations of GRB 090531A
  26. GRB 090618: AGILE observations
  27. GRB 090617: Fermi GBM detection
  28. GRB 090618: Enhanced Swift-XRT position
  29. GRB 090618 Faulkes Telescope North observations
  30. GRB 090618: ROTSE-III Detection of Optical Counterpart
  31. GRB090618: P60 Optical Afterglow
  32. GRB 090618: Swift detection of a bright burst with optical afterglow
  33. GRB 090616: Fermi GBM detection
  34. GRB 090612: Fermi GBM detection
  35. GRB 090610C: Fermi GBM detection
  36. GRB 090610B: Fermi GBM detection
  37. GRB 090610: Fermi GBM detection
  38. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  39. GRB 090602: Suzaku WAM observation of the prompt emission
  40. RXTE Discovery of Pulsations from SGR 0418+5729
  41. GRB 090531B: Fermi GBM detection
  42. Konus-RF observation of SGR burst 090605A
  43. Discovery of a new soft gamma repeater source, SGR 0418+5729
  44. GRB 090608: Fermi GBM detection
  45. GRB 090606: Fermi GBM detection
  46. GRB 090607: XRT Team Refined Analysis
  47. GRB 090607: Swift/UVOT Upper Limits
  48. GRB 090607: Swift-BAT refined analysis of the SHB
  49. GRB 090607: GRAS001 optical observations
  50. GRB 090607: Faulkes Telescope North observations
  51. GRB 090607: Swift detection of a burst
  52. GRB 090530B: Suzaku WAM observation of the prompt emission
  53. GRB 090530: Further NOT optical observations
  54. GRB 090530: RTT150 Optical Observation
  55. GRB 090602: Fermi GBM detection
  56. GRB 090529A: RTT150 Optical Observations
  57. GMRT observation of GRB 090424 afterglow
  58. GRB 090528: Suzaku WAM observation of the prompt emission
  59. GRB090529: Further NOT optical observations
  60. GRB 090531B: GROND observation
  61. GRB 090528B: Suzaku WAM observation of the prompt emission
  62. GRB 090530: Early RAPTOR Optical Observations
  63. GRB090529B: ROVOR Upper Limits
  64. GRB 090531A: SARA upper limit
  65. GRB 090531B: Swift/BAT spectral lag results
  66. GRB 090529C: Fermi GBM detection
  67. GRB 090529B: Fermi GBM detection
  68. GRB 090530B: Fermi GBM detection
  69. Corrections to GRB 090531B Swift/UVOT Upper Limits
  70. GRB 090531B, RIMOTS optical upper limits
  71. GRB 090531B: Swift/UVOT Upper Limits
  72. GRB 090528B: MASTER-II Kourovka optical limit
  73. GRB 090529: MITSuME optical observation
  74. GRB 090530: GRT Optical Observation
  75. GRB 090531B: Swift-BAT refined analysis
  76. GRB 090531B: Swift-XRT candidate afterglow position
  77. GRB 090531B: ROTSE-III Optical Limits
  78. GRB 090531: Swift-BAT refined analysis
  79. GRB090530: R-band Observation
  80. GRB 090530: break in light curve
  81. GRB 090531: GROND upper limits
  82. GRB 090531: P60 Observations
  83. GRB 090529: NOT optical observations
  84. GRB 090530: NOT optical observations
  85. GRB090530: Swift XRT refined analysis
  86. GRB090530: Swift/UVOT afterglow detection
  87. GRB 090529: Swift-XRT refined analysis
  88. GRB 090528B: Fermi GBM detection
  89. GRB 090528: Fermi GBM detection
  90. GRB 090530: Enhanced Swift-XRT position
  91. Strong radio emission from SN 2007bg one year after the explosion - detection of spreading, off-axis GRB jet?
  92. GRB 090530: Swift-BAT refined analysis
  93. GRB 090530: GRAS002 refined OA analysis
  94. GRB 090530: GRAS002 optical observations
  95. GRB 090530: PAIRITEL NIR Detections
  96. GRB 090530A: ROTSE-III Detection of Optical Counterpart
  97. GRB 090530: Swift detection of a burst with an optical counterpart
  98. GRB 090529: TLS Afterglow Observations
  99. GRB090529: UVOT/Swift detection of a brightening optical afterglow
  100. GRB 090529: Swift-BAT refined analysis

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