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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"

26299 results found.

  1. VLA radio detection of GRB 090618
  2. GRB090618 - Continued optical monitoring and light curve break
  3. GRB 090618: Swift-BAT refined analysis
  4. GRB090618: Swift-XRT team refined analysis
  5. GRB090618: Swift/UVOT bright afterglow detection
  6. GRB 090618: SDSS host detection
  7. GRB 090618: AGILE observations
  8. GRB 090617: Fermi GBM detection
  9. GRB 090618: LOAO R-band Observation
  10. GRB 090618: Enhanced Swift-XRT position
  11. GRB 090618 Faulkes Telescope North observations
  12. GRB 090618: Swift detection of a bright burst with optical afterglow
  13. GRB 090616: Fermi GBM detection
  14. GRB 090612: Fermi GBM detection
  15. GRB 090610C: Fermi GBM detection
  16. GRB 090610B: Fermi GBM detection
  17. GRB 090610: Fermi GBM detection
  18. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  19. GRB 090602: Suzaku WAM observation of the prompt emission
  20. GRB 090531B: Fermi GBM detection
  21. Konus-RF observation of SGR burst 090605A
  22. Discovery of a new soft gamma repeater source, SGR 0418+5729
  23. GRB 090608: Fermi GBM detection
  24. GRB 090606: Fermi GBM detection
  25. GRB 090607: XRT Team Refined Analysis
  26. GRB 090607: Swift-BAT refined analysis of the SHB
  27. GRB 090607: Swift detection of a burst
  28. GRB 090530B: Suzaku WAM observation of the prompt emission
  29. GRB 090530: RTT150 Optical Observation
  30. GRB 090602: Fermi GBM detection
  31. GRB 090529A: RTT150 Optical Observations
  32. GMRT observation of GRB 090424 afterglow
  33. GRB 090528: Suzaku WAM observation of the prompt emission
  34. GRB090529: Further NOT optical observations
  35. GRB 090528B: Suzaku WAM observation of the prompt emission
  36. GRB 090530: Early RAPTOR Optical Observations
  37. GRB090529B: ROVOR Upper Limits
  38. GRB 090529C: Fermi GBM detection
  39. GRB 090529B: Fermi GBM detection
  40. GRB 090530B: Fermi GBM detection
  41. GRB 090529: MITSuME optical observation
  42. GRB 090530: GRT Optical Observation
  43. GRB 090531B: Swift-BAT refined analysis
  44. GRB 090531B: Swift detection of a burst
  45. GRB 090531: Swift-BAT refined analysis
  46. GRB090530: R-band Observation
  47. GRB 090530: break in light curve
  48. GRB 090529: VLT spectroscopic redshift
  49. GRB 090531: Swift detection of a burst
  50. GRB 090529: NOT optical observations
  51. GRB090530: Swift XRT refined analysis
  52. GRB 090529: Swift-XRT refined analysis
  53. GRB 090529: OSN optical observations
  54. GRB 090528B: Fermi GBM detection
  55. GRB 090528: Fermi GBM detection
  56. GRB 090530: Enhanced Swift-XRT position
  57. GRB 090530: Swift-BAT refined analysis
  58. GRB 090530: Swift detection of a burst with an optical counterpart
  59. GRB 090529: TLS Afterglow Observations
  60. GRB090529: UVOT/Swift detection of a brightening optical afterglow
  61. GRB 090529: Swift-BAT refined analysis
  62. GRB 090529: Enhanced Swift-XRT position
  63. GRB 090529: Swift detection of a burst
  64. GRB 090520D: Fermi GBM detection
  65. GRB 090520C: Fermi GBM detection
  66. GRB 090520B: Fermi GBM detection
  67. GRB090518B optical limit by "Pi of the Sky"
  68. GRB 090522 : Fermi GBM detection
  69. GRB 090524: Fermi GBM detection
  70. GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
  71. GRB 090518: Fermi GBM detection
  72. GRB 090516C: Fermi GBM detection
  73. GRB 090423: Fermi GBM T90 follow-up analysis results
  74. GRB 090516: Fermi GBM observation
  75. GRB 090516B: Fermi GBM detection
  76. GRB 090519B: Fermi GBM detection
  77. GRB 090519: Swift-XRT refined analysis
  78. GRB 090519: NOT refined analysis
  79. GRB 090519: VLT spectroscopic redshift
  80. GRB 090519, Swift-BAT refined analysis
  81. GRB 090519: Enhanced Swift-XRT position
  82. GRB 090519: NOT afterglow candidate
  83. GRB 090519: FARO Chante Perdrix Observatory optical observations
  84. GRB 090519: TAROT Calern observatory optical observations
  85. GRB 090519: Swift detection of a burst
  86. GRB 090511: Fermi GBM Detection
  87. GRB 090514: Fermi GBM detection
  88. GRB 090518, Swift-BAT refined analysis
  89. GRB 090518B: Fermi GBM detection
  90. GRB090513: Fermi GBM detection
  91. GRB090518 : Optical upper limit by MOA-II telescope
  92. GRB 090518: Swift-XRT refined analysis
  93. GRB 090518: Enhanced Swift-XRT position
  94. GRB 090518: Swift detection of a burst
  95. GRB 090516: Swift-BAT refined analysis
  96. GRB 090516: VLT spectrum (correction & update)
  97. GRB 090516: Swift XRT refined analysis
  98. GRB 090516: Enhanced Swift-XRT position
  99. GRB 090516: Swift detection of a burst
  100. GRB 090515: ROVOR Upper Limit

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