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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"

28047 results found.

  1. GRB 090621B: GRT Optical Observation
  2. GRB 090621A: GRT Optical Observation
  3. GRB 090621B: I-band observations from 1.23m CAHA
  4. GRB 090621D: Fermi GBM detection
  5. GRB 090621C: Fermi GBM detection
  6. GRB 090621B: P60 Observations
  7. GRB 090621B: VLA observations
  8. GRB 090620: Fermi GBM detecion
  9. GRB 090621B: Swift/UVOT Upper Limits
  10. GRB 090621B: Swift-BAT refined analysis
  11. GRB 090621B: Swift-XRT refined analysis
  12. GRB 090621B: RTT150 optical observations
  13. GRB 090621B: Swift detection of a short hard burst
  14. GRB 090621: Swift/UVOT Upper Limits
  15. GRB 090621: Swift-XRT Team refined analysis
  16. GRB090618: Spectrum and photometry from 6.0m BTA
  17. GRB 090621: Swift detection of a burst
  18. GRB090618, underlying supernova search
  19. GRB090618: OAA-OAUV Optical observations
  20. GRB 090618: Fermi GBM observation
  21. GRB 090618, Swift-BAT refined spectral analysis
  22. VLA radio detection of GRB 090618
  23. GRB 090618 15GHz radio detection
  24. GRB090618 - Continued optical monitoring and light curve break
  25. GRB 090618: Swift-BAT refined analysis
  26. GRB 090618: SARA observations
  27. GRB090618: Swift-XRT team refined analysis
  28. GRB090618: Swift/UVOT bright afterglow detection
  29. GRB 090618: SDSS host detection
  30. Swift XRT observations of GRB 090531A
  31. GRB 090618: AGILE observations
  32. GRB 090617: Fermi GBM detection
  33. GRB 090618: Enhanced Swift-XRT position
  34. GRB 090618 Faulkes Telescope North observations
  35. GRB 090618: ROTSE-III Detection of Optical Counterpart
  36. GRB090618: P60 Optical Afterglow
  37. GRB 090618: Swift detection of a bright burst with optical afterglow
  38. GRB 090616: Fermi GBM detection
  39. GRB 090612: Fermi GBM detection
  40. GRB 090610C: Fermi GBM detection
  41. GRB 090610B: Fermi GBM detection
  42. GRB 090610: Fermi GBM detection
  43. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  44. GRB 090602: Suzaku WAM observation of the prompt emission
  45. RXTE Discovery of Pulsations from SGR 0418+5729
  46. GRB 090531B: Fermi GBM detection
  47. Konus-RF observation of SGR burst 090605A
  48. Discovery of a new soft gamma repeater source, SGR 0418+5729
  49. GRB 090608: Fermi GBM detection
  50. GRB 090606: Fermi GBM detection
  51. GRB 090607: XRT Team Refined Analysis
  52. GRB 090607: Swift/UVOT Upper Limits
  53. GRB 090607: Swift-BAT refined analysis of the SHB
  54. GRB 090607: GRAS001 optical observations
  55. GRB 090607: Faulkes Telescope North observations
  56. GRB 090607: Swift detection of a burst
  57. GRB 090530B: Suzaku WAM observation of the prompt emission
  58. GRB 090530: Further NOT optical observations
  59. GRB 090530: RTT150 Optical Observation
  60. GRB 090602: Fermi GBM detection
  61. GRB 090529A: RTT150 Optical Observations
  62. GMRT observation of GRB 090424 afterglow
  63. GRB 090528: Suzaku WAM observation of the prompt emission
  64. GRB090529: Further NOT optical observations
  65. GRB 090531B: GROND observation
  66. GRB 090528B: Suzaku WAM observation of the prompt emission
  67. GRB 090530: Early RAPTOR Optical Observations
  68. GRB090529B: ROVOR Upper Limits
  69. GRB 090531A: SARA upper limit
  70. GRB 090531B: Swift/BAT spectral lag results
  71. GRB 090529C: Fermi GBM detection
  72. GRB 090529B: Fermi GBM detection
  73. GRB 090530B: Fermi GBM detection
  74. Corrections to GRB 090531B Swift/UVOT Upper Limits
  75. GRB 090531B, RIMOTS optical upper limits
  76. GRB 090531B: Swift/UVOT Upper Limits
  77. GRB 090528B: MASTER-II Kourovka optical limit
  78. GRB 090529: MITSuME optical observation
  79. GRB 090530: GRT Optical Observation
  80. GRB 090531B: Swift-BAT refined analysis
  81. GRB 090531B: Swift-XRT candidate afterglow position
  82. GRB 090531B: ROTSE-III Optical Limits
  83. GRB 090531: Swift-BAT refined analysis
  84. GRB090530: R-band Observation
  85. GRB 090530: break in light curve
  86. GRB 090531: GROND upper limits
  87. GRB 090531: P60 Observations
  88. GRB 090529: NOT optical observations
  89. GRB 090530: NOT optical observations
  90. GRB090530: Swift XRT refined analysis
  91. GRB090530: Swift/UVOT afterglow detection
  92. GRB 090529: Swift-XRT refined analysis
  93. GRB 090528B: Fermi GBM detection
  94. GRB 090528: Fermi GBM detection
  95. GRB 090530: Enhanced Swift-XRT position
  96. Strong radio emission from SN 2007bg one year after the explosion - detection of spreading, off-axis GRB jet?
  97. GRB 090530: Swift-BAT refined analysis
  98. GRB 090530: GRAS002 refined OA analysis
  99. GRB 090530: GRAS002 optical observations
  100. GRB 090530: PAIRITEL NIR Detections

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