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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. GRB 090628: Swift-BAT refined analysis
  2. GRB090618: 15GHz radio emission faded
  3. GRB 090628: GROND upper limits
  4. GRB 090628: Enhanced Swift-XRT position
  5. GRB 090628: 1.23m CAHA optical observations
  6. GRB 090626: IPN localization
  7. GRB 090628: Swift/UVOT Finding Chart Observation
  8. GRB 090628: Swift XRT position
  9. GRB 090628: Swift detection of a burst
  10. Fermi LAT observations of GRB 090626
  11. GRB 090625B: Fermi GBM observation
  12. GRB 090423: Spitzer observations of the z~8.3 burst
  13. GRB 090625B: Swift/UVOT Upper Limits
  14. GRB 090625B: Swift-XRT refined analysis
  15. GRB 090626: Fermi GBM detection
  16. GRB 090625B: GROND upper limits
  17. GRB 090623: Suzaku WAM observation of the prompt emission
  18. GRB090618: HCT optical observations
  19. GRB 090618: SARA Second Epoch Observations
  20. GRB 090625B: Faulkes Telescope South observations
  21. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  22. GRB 090625B: a long GRB localized by INTEGRAL
  23. GRB 090625: Fermi GBM detection
  24. GRB 090618: Correction to GCN 9568
  25. GRB 090617: Suzaku WAM observation of the prompt emission
  26. GRB 090618: Suzaku WAM observation of the prompt emission
  27. GRB 090621A: Enhanced Swift-XRT position
  28. GRB 090623: Fermi GBM detection
  29. GRB 090621B: GRT Optical Observation
  30. GRB 090621A: GRT Optical Observation
  31. PAIRITEL observations of GRB 090618
  32. GRB 090621B: Fermi GBM detection
  33. GRB 090621B: I-band observations from 1.23m CAHA
  34. GRB 090621D: Fermi GBM detection
  35. GRB 090621B: Gemini spectrum of afterglow candidate
  36. GRB 090621C: Fermi GBM detection
  37. GRB 090621B: P60 Observations
  38. GRB 090621: Fermi GBM observation
  39. GRB 090621B: VLA observations
  40. GRB 090620: Fermi GBM detecion
  41. Konus-Wind and Konus-RF observations of GRB 090618
  42. GRB 090621B: Swift/UVOT Upper Limits
  43. GRB 090621B: Swift-BAT refined analysis
  44. GRB 090621B: Swift-XRT refined analysis
  45. GRB 090621B: RTT150 optical observations
  46. GRB 090618: RTT150 optical observations
  47. GRB 090621B: Optical Observations
  48. GRB 090621A: Swift-BAT refined analysis
  49. GRB 090621B: Swift detection of a short hard burst
  50. GRB 090621: Swift/UVOT Upper Limits
  51. GRB 090621: Swift-XRT Team refined analysis
  52. GRB090618: Spectrum and photometry from 6.0m BTA
  53. GRB 090618: BOAO V-band Observation
  54. GRB 090621: Swift detection of a burst
  55. GRB 090618: ZTSh optical observations
  56. GRB 090618 : WSRT radio detection
  57. GRB090618, underlying supernova search
  58. GRB090618: OAA-OAUV Optical observations
  59. GRB 090618: Fermi GBM observation
  60. GRB 090618, Swift-BAT refined spectral analysis
  61. VLA radio detection of GRB 090618
  62. GRB 090618 15GHz radio detection
  63. GRB090618 - Continued optical monitoring and light curve break
  64. GRB 090618: Swift-BAT refined analysis
  65. GRB 090618: SARA observations
  66. GRB090618: Swift-XRT team refined analysis
  67. GRB090618: Swift/UVOT bright afterglow detection
  68. GRB 090618: SDSS host detection
  69. Swift XRT observations of GRB 090531A
  70. GRB 090618: AGILE observations
  71. GRB 090617: Fermi GBM detection
  72. GRB 090618: LOAO R-band Observation
  73. GRB 090618: Enhanced Swift-XRT position
  74. GRB 090618 Faulkes Telescope North observations
  75. Optical observations of GRB 090618
  76. GRB 090618: Lick/KAST Spectroscopy
  77. GRB 090618: OA behavior from KAIT
  78. GRB 090618: planned XMM-Newton observation
  79. GRB 090618: ROTSE-III Detection of Optical Counterpart
  80. GRB 090618: KAIT optical afterglow
  81. GRB090618: P60 Optical Afterglow
  82. GRB 090618: Swift detection of a bright burst with optical afterglow
  83. GRB 090616: Fermi GBM detection
  84. GRB 090612: Fermi GBM detection
  85. GRB 090610C: Fermi GBM detection
  86. GRB 090610B: Fermi GBM detection
  87. GRB 090610: Fermi GBM detection
  88. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  89. GRB 090602: Suzaku WAM observation of the prompt emission
  90. GRB 090424: WSRT Radio Observations
  91. GRB 090423: WSRT Radio Observations
  92. RXTE Discovery of Pulsations from SGR 0418+5729
  93. GRB 090531B: Fermi GBM detection
  94. Konus-RF observation of SGR burst 090605A
  95. Discovery of a new soft gamma repeater source, SGR 0418+5729
  96. GRB 090608: Fermi GBM detection
  97. GRB 090606: Fermi GBM detection
  98. GRB 090607: XRT Team Refined Analysis
  99. GRB 090607: Swift/UVOT Upper Limits
  100. GRB 090607: Swift-BAT refined analysis of the SHB

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Download all Circulars as a .tar.gz archive:
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