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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"

28059 results found.

  1. GRB 090625B: GROND upper limits
  2. GRB 090623: Suzaku WAM observation of the prompt emission
  3. GRB090618: HCT optical observations
  4. GRB 090618: SARA Second Epoch Observations
  5. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  6. GRB 090625B: a long GRB localized by INTEGRAL
  7. GRB 090625: Fermi GBM detection
  8. GRB 090618: Correction to GCN 9568
  9. GRB 090617: Suzaku WAM observation of the prompt emission
  10. GRB 090618: Suzaku WAM observation of the prompt emission
  11. GRB 090621A: Enhanced Swift-XRT position
  12. GRB 090623: Fermi GBM detection
  13. GRB 090621B: GRT Optical Observation
  14. GRB 090621A: GRT Optical Observation
  15. GRB 090621B: I-band observations from 1.23m CAHA
  16. GRB 090621D: Fermi GBM detection
  17. GRB 090621C: Fermi GBM detection
  18. GRB 090621B: P60 Observations
  19. GRB 090621B: VLA observations
  20. GRB 090620: Fermi GBM detecion
  21. GRB 090621B: Swift/UVOT Upper Limits
  22. GRB 090621B: Swift-BAT refined analysis
  23. GRB 090621B: Swift-XRT refined analysis
  24. GRB 090621B: RTT150 optical observations
  25. GRB 090621B: Swift detection of a short hard burst
  26. GRB 090621: Swift/UVOT Upper Limits
  27. GRB 090621: Swift-XRT Team refined analysis
  28. GRB090618: Spectrum and photometry from 6.0m BTA
  29. GRB 090621: Swift detection of a burst
  30. GRB090618, underlying supernova search
  31. GRB090618: OAA-OAUV Optical observations
  32. GRB 090618: Fermi GBM observation
  33. GRB 090618, Swift-BAT refined spectral analysis
  34. VLA radio detection of GRB 090618
  35. GRB 090618 15GHz radio detection
  36. GRB090618 - Continued optical monitoring and light curve break
  37. GRB 090618: Swift-BAT refined analysis
  38. GRB 090618: SARA observations
  39. GRB090618: Swift-XRT team refined analysis
  40. GRB090618: Swift/UVOT bright afterglow detection
  41. GRB 090618: SDSS host detection
  42. Swift XRT observations of GRB 090531A
  43. GRB 090618: AGILE observations
  44. GRB 090617: Fermi GBM detection
  45. GRB 090618: Enhanced Swift-XRT position
  46. GRB 090618 Faulkes Telescope North observations
  47. GRB 090618: ROTSE-III Detection of Optical Counterpart
  48. GRB090618: P60 Optical Afterglow
  49. GRB 090618: Swift detection of a bright burst with optical afterglow
  50. GRB 090616: Fermi GBM detection
  51. GRB 090612: Fermi GBM detection
  52. GRB 090610C: Fermi GBM detection
  53. GRB 090610B: Fermi GBM detection
  54. GRB 090610: Fermi GBM detection
  55. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  56. GRB 090602: Suzaku WAM observation of the prompt emission
  57. RXTE Discovery of Pulsations from SGR 0418+5729
  58. GRB 090531B: Fermi GBM detection
  59. Konus-RF observation of SGR burst 090605A
  60. Discovery of a new soft gamma repeater source, SGR 0418+5729
  61. GRB 090608: Fermi GBM detection
  62. GRB 090606: Fermi GBM detection
  63. GRB 090607: XRT Team Refined Analysis
  64. GRB 090607: Swift/UVOT Upper Limits
  65. GRB 090607: Swift-BAT refined analysis of the SHB
  66. GRB 090607: GRAS001 optical observations
  67. GRB 090607: Faulkes Telescope North observations
  68. GRB 090607: Swift detection of a burst
  69. GRB 090530B: Suzaku WAM observation of the prompt emission
  70. GRB 090530: Further NOT optical observations
  71. GRB 090530: RTT150 Optical Observation
  72. GRB 090602: Fermi GBM detection
  73. GRB 090529A: RTT150 Optical Observations
  74. GMRT observation of GRB 090424 afterglow
  75. GRB 090528: Suzaku WAM observation of the prompt emission
  76. GRB090529: Further NOT optical observations
  77. GRB 090531B: GROND observation
  78. GRB 090528B: Suzaku WAM observation of the prompt emission
  79. GRB 090530: Early RAPTOR Optical Observations
  80. GRB090529B: ROVOR Upper Limits
  81. GRB 090531A: SARA upper limit
  82. GRB 090531B: Swift/BAT spectral lag results
  83. GRB 090529C: Fermi GBM detection
  84. GRB 090529B: Fermi GBM detection
  85. GRB 090530B: Fermi GBM detection
  86. Corrections to GRB 090531B Swift/UVOT Upper Limits
  87. GRB 090531B, RIMOTS optical upper limits
  88. GRB 090531B: Swift/UVOT Upper Limits
  89. GRB 090528B: MASTER-II Kourovka optical limit
  90. GRB 090529: MITSuME optical observation
  91. GRB 090530: GRT Optical Observation
  92. GRB 090531B: Swift-BAT refined analysis
  93. GRB 090531B: Swift-XRT candidate afterglow position
  94. GRB 090531B: ROTSE-III Optical Limits
  95. GRB 090531: Swift-BAT refined analysis
  96. GRB090530: R-band Observation
  97. GRB 090530: break in light curve
  98. GRB 090531: GROND upper limits
  99. GRB 090531: P60 Observations
  100. GRB 090529: NOT optical observations

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