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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"

28044 results found.

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

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