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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"

28051 results found.

  1. GRB 090617: Suzaku WAM observation of the prompt emission
  2. GRB 090618: Suzaku WAM observation of the prompt emission
  3. GRB 090621A: Enhanced Swift-XRT position
  4. GRB 090623: Fermi GBM detection
  5. GRB 090621B: GRT Optical Observation
  6. GRB 090621A: GRT Optical Observation
  7. GRB 090621B: I-band observations from 1.23m CAHA
  8. GRB 090621D: Fermi GBM detection
  9. GRB 090621C: Fermi GBM detection
  10. GRB 090621B: P60 Observations
  11. GRB 090621B: VLA observations
  12. GRB 090620: Fermi GBM detecion
  13. GRB 090621B: Swift/UVOT Upper Limits
  14. GRB 090621B: Swift-BAT refined analysis
  15. GRB 090621B: Swift-XRT refined analysis
  16. GRB 090621B: RTT150 optical observations
  17. GRB 090621B: Swift detection of a short hard burst
  18. GRB 090621: Swift/UVOT Upper Limits
  19. GRB 090621: Swift-XRT Team refined analysis
  20. GRB090618: Spectrum and photometry from 6.0m BTA
  21. GRB 090621: Swift detection of a burst
  22. GRB090618, underlying supernova search
  23. GRB090618: OAA-OAUV Optical observations
  24. GRB 090618: Fermi GBM observation
  25. GRB 090618, Swift-BAT refined spectral analysis
  26. VLA radio detection of GRB 090618
  27. GRB 090618 15GHz radio detection
  28. GRB090618 - Continued optical monitoring and light curve break
  29. GRB 090618: Swift-BAT refined analysis
  30. GRB 090618: SARA observations
  31. GRB090618: Swift-XRT team refined analysis
  32. GRB090618: Swift/UVOT bright afterglow detection
  33. GRB 090618: SDSS host detection
  34. Swift XRT observations of GRB 090531A
  35. GRB 090618: AGILE observations
  36. GRB 090617: Fermi GBM detection
  37. GRB 090618: Enhanced Swift-XRT position
  38. GRB 090618 Faulkes Telescope North observations
  39. GRB 090618: ROTSE-III Detection of Optical Counterpart
  40. GRB090618: P60 Optical Afterglow
  41. GRB 090618: Swift detection of a bright burst with optical afterglow
  42. GRB 090616: Fermi GBM detection
  43. GRB 090612: Fermi GBM detection
  44. GRB 090610C: Fermi GBM detection
  45. GRB 090610B: Fermi GBM detection
  46. GRB 090610: Fermi GBM detection
  47. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  48. GRB 090602: Suzaku WAM observation of the prompt emission
  49. RXTE Discovery of Pulsations from SGR 0418+5729
  50. GRB 090531B: Fermi GBM detection
  51. Konus-RF observation of SGR burst 090605A
  52. Discovery of a new soft gamma repeater source, SGR 0418+5729
  53. GRB 090608: Fermi GBM detection
  54. GRB 090606: Fermi GBM detection
  55. GRB 090607: XRT Team Refined Analysis
  56. GRB 090607: Swift/UVOT Upper Limits
  57. GRB 090607: Swift-BAT refined analysis of the SHB
  58. GRB 090607: GRAS001 optical observations
  59. GRB 090607: Faulkes Telescope North observations
  60. GRB 090607: Swift detection of a burst
  61. GRB 090530B: Suzaku WAM observation of the prompt emission
  62. GRB 090530: Further NOT optical observations
  63. GRB 090530: RTT150 Optical Observation
  64. GRB 090602: Fermi GBM detection
  65. GRB 090529A: RTT150 Optical Observations
  66. GMRT observation of GRB 090424 afterglow
  67. GRB 090528: Suzaku WAM observation of the prompt emission
  68. GRB090529: Further NOT optical observations
  69. GRB 090531B: GROND observation
  70. GRB 090528B: Suzaku WAM observation of the prompt emission
  71. GRB 090530: Early RAPTOR Optical Observations
  72. GRB090529B: ROVOR Upper Limits
  73. GRB 090531A: SARA upper limit
  74. GRB 090531B: Swift/BAT spectral lag results
  75. GRB 090529C: Fermi GBM detection
  76. GRB 090529B: Fermi GBM detection
  77. GRB 090530B: Fermi GBM detection
  78. Corrections to GRB 090531B Swift/UVOT Upper Limits
  79. GRB 090531B, RIMOTS optical upper limits
  80. GRB 090531B: Swift/UVOT Upper Limits
  81. GRB 090528B: MASTER-II Kourovka optical limit
  82. GRB 090529: MITSuME optical observation
  83. GRB 090530: GRT Optical Observation
  84. GRB 090531B: Swift-BAT refined analysis
  85. GRB 090531B: Swift-XRT candidate afterglow position
  86. GRB 090531B: ROTSE-III Optical Limits
  87. GRB 090531: Swift-BAT refined analysis
  88. GRB090530: R-band Observation
  89. GRB 090530: break in light curve
  90. GRB 090531: GROND upper limits
  91. GRB 090531: P60 Observations
  92. GRB 090529: NOT optical observations
  93. GRB 090530: NOT optical observations
  94. GRB090530: Swift XRT refined analysis
  95. GRB090530: Swift/UVOT afterglow detection
  96. GRB 090529: Swift-XRT refined analysis
  97. GRB 090528B: Fermi GBM detection
  98. GRB 090528: Fermi GBM detection
  99. GRB 090530: Enhanced Swift-XRT position
  100. Strong radio emission from SN 2007bg one year after the explosion - detection of spreading, off-axis GRB jet?

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