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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"

21772 results found.

  1. RXTE Discovery of Pulsations from SGR 0418+5729
  2. Konus-RF observation of SGR burst 090605A
  3. Discovery of a new soft gamma repeater source, SGR 0418+5729
  4. GRB 090607: Swift/UVOT Upper Limits
  5. GRB 090607: GRAS001 optical observations
  6. GRB 090607: Faulkes Telescope North observations
  7. GRB 090607: Swift detection of a burst
  8. GRB 090530B: Suzaku WAM observation of the prompt emission
  9. GRB 090530: Further NOT optical observations
  10. GRB 090530: RTT150 Optical Observation
  11. GRB 090529A: RTT150 Optical Observations
  12. GMRT observation of GRB 090424 afterglow
  13. GRB 090528: Suzaku WAM observation of the prompt emission
  14. GRB090529: Further NOT optical observations
  15. GRB 090531B: GROND observation
  16. GRB 090528B: Suzaku WAM observation of the prompt emission
  17. GRB 090530: Early RAPTOR Optical Observations
  18. GRB090529B: ROVOR Upper Limits
  19. GRB 090531A: SARA upper limit
  20. GRB 090531B: Swift/BAT spectral lag results
  21. GRB 090529C: Fermi GBM detection
  22. GRB 090530B: Fermi GBM detection
  23. Corrections to GRB 090531B Swift/UVOT Upper Limits
  24. GRB 090531B, RIMOTS optical upper limits
  25. GRB 090531B: Swift/UVOT Upper Limits
  26. GRB 090529: MITSuME optical observation
  27. GRB 090530: GRT Optical Observation
  28. GRB 090531B: Swift-XRT candidate afterglow position
  29. GRB 090531B: ROTSE-III Optical Limits
  30. GRB 090530: break in light curve
  31. GRB 090531: GROND upper limits
  32. GRB 090531: P60 Observations
  33. GRB 090529: NOT optical observations
  34. GRB 090530: NOT optical observations
  35. GRB090530: Swift/UVOT afterglow detection
  36. GRB 090530: Enhanced Swift-XRT position
  37. GRB 090530: GRAS002 refined OA analysis
  38. GRB 090530: GRAS002 optical observations
  39. GRB 090530: PAIRITEL NIR Detections
  40. GRB 090530: Swift detection of a burst with an optical counterpart
  41. GRB 090529: TLS Afterglow Observations
  42. GRB090529: UVOT/Swift detection of a brightening optical afterglow
  43. GRB 090529: Swift-BAT refined analysis
  44. GRB 090529: Enhanced Swift-XRT position
  45. GRB 090529: Preliminary Swift/UVOT Upper Limit
  46. GRB 090529: Swift detection of a burst
  47. GRB 090518 - NOT upper limit
  48. GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
  49. GRB 090520: GROND upper limits
  50. GRB 090520 Swift-BAT detection of a burst in ground analysis
  51. GRB 090519: NOT refined analysis
  52. GRB 090519: GROND observation
  53. GRB 090519: Swift/UVOT Upper Limits
  54. GRB 090519: Enhanced Swift-XRT position
  55. GRB 090519: NOT afterglow candidate
  56. GRB 090519: FARO Chante Perdrix Observatory optical observations
  57. GRB 090519: TAROT Calern observatory optical observations
  58. GRB 090519: Swift detection of a burst
  59. GRB 090518: Swift/UVOT Upper Limits
  60. GRB 090516: Observations from Stardome Observatory
  61. GRB090518: GROND upper limits
  62. GRB 090518: P60 Observations
  63. GRB 090516, RIMOTS optical upper limits
  64. GRB090518 : Optical upper limit by MOA-II telescope
  65. GRB 090518: Enhanced Swift-XRT position
  66. GRB 090518: Swift detection of a burst
  67. GRB 090516: GROND OBSERVATIONS
  68. GRB 090516 - Zadko Telescope observations
  69. GRB 090516: NOT optical observations
  70. GRB 090516: Swift/UVOT Observations
  71. GRB 090516: Enhanced Swift-XRT position
  72. GRB 090516: Swift detection of a burst
  73. GRB 090515: VLA observations
  74. GRB 090515: Lick Upper Limits
  75. GRB 090515: ROVOR Upper Limit
  76. GRB 090515: MMT/MMIRS NIR Upper Limit
  77. GRB 090515: Swift/UVOT Observations
  78. GRB 090515: Enhanced Swift-XRT position
  79. GRB 090509 - Zadko Telescope observations
  80. GRB 090515: Gemini-N upper limit
  81. GRB 090515: WIYN NIR Upper Limit
  82. GRB 090515: Super-LOTIS Upper Limits
  83. GRB 090515: PAIRITEL Upper Limits
  84. GRB 090515: ROTSE-III Optical Limits
  85. GRB 090515: Swift detection of a short burst
  86. GRB 090510: Suzaku WAM observation of the prompt emission
  87. GRB 090510, Radio limits
  88. GRB090510: VLT/FORS2 spectroscopic redshift
  89. GRB 090510: GROND observations
  90. GRB 090509, further Swift-BAT refined analysis
  91. Konus-Wind observation of GRB 090510
  92. AGILE detection of GRB 090510
  93. GRB 090510: UVOT refined analysis
  94. GRB 090510: Enhanced Swift-XRT position
  95. GRB 090510: NOT afterglow confirmation
  96. GRB 090510: Fermi GBM detection
  97. Fermi LAT detection of GRB 090510
  98. GRB 090509, SMARTS optical/IR afterglow observations
  99. GRB 090510: Swift detection of a short hard burst
  100. GRB 090509: GROND further analysis and redshift limit

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