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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"

21263 results found.

  1. GRB 090530: RTT150 Optical Observation
  2. GRB 090529A: RTT150 Optical Observations
  3. GMRT observation of GRB 090424 afterglow
  4. GRB 090528: Suzaku WAM observation of the prompt emission
  5. GRB090529: Further NOT optical observations
  6. GRB 090531B: GROND observation
  7. GRB 090528B: Suzaku WAM observation of the prompt emission
  8. GRB 090530: Early RAPTOR Optical Observations
  9. GRB090529B: ROVOR Upper Limits
  10. GRB 090531A: SARA upper limit
  11. GRB 090531B: Swift/BAT spectral lag results
  12. GRB 090529C: Fermi GBM detection
  13. GRB 090530B: Fermi GBM detection
  14. Corrections to GRB 090531B Swift/UVOT Upper Limits
  15. GRB 090531B, RIMOTS optical upper limits
  16. GRB 090531B: Swift/UVOT Upper Limits
  17. GRB 090529: MITSuME optical observation
  18. GRB 090530: GRT Optical Observation
  19. GRB 090531B: Swift-XRT candidate afterglow position
  20. GRB 090531B: ROTSE-III Optical Limits
  21. GRB 090530: break in light curve
  22. GRB 090531: GROND upper limits
  23. GRB 090531: P60 Observations
  24. GRB 090529: NOT optical observations
  25. GRB 090530: NOT optical observations
  26. GRB090530: Swift/UVOT afterglow detection
  27. GRB 090530: Enhanced Swift-XRT position
  28. GRB 090530: GRAS002 refined OA analysis
  29. GRB 090530: GRAS002 optical observations
  30. GRB 090530: PAIRITEL NIR Detections
  31. GRB 090530: Swift detection of a burst with an optical counterpart
  32. GRB 090529: TLS Afterglow Observations
  33. GRB090529: UVOT/Swift detection of a brightening optical afterglow
  34. GRB 090529: Swift-BAT refined analysis
  35. GRB 090529: Enhanced Swift-XRT position
  36. GRB 090529: Preliminary Swift/UVOT Upper Limit
  37. GRB 090529: Swift detection of a burst
  38. GRB 090518 - NOT upper limit
  39. GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
  40. GRB 090520: GROND upper limits
  41. GRB 090520 Swift-BAT detection of a burst in ground analysis
  42. GRB 090519: NOT refined analysis
  43. GRB 090519: GROND observation
  44. GRB 090519: Swift/UVOT Upper Limits
  45. GRB 090519: Enhanced Swift-XRT position
  46. GRB 090519: NOT afterglow candidate
  47. GRB 090519: FARO Chante Perdrix Observatory optical observations
  48. GRB 090519: TAROT Calern observatory optical observations
  49. GRB 090519: Swift detection of a burst
  50. GRB 090518: Swift/UVOT Upper Limits
  51. GRB 090516: Observations from Stardome Observatory
  52. GRB090518: GROND upper limits
  53. GRB 090518: P60 Observations
  54. GRB 090516, RIMOTS optical upper limits
  55. GRB090518 : Optical upper limit by MOA-II telescope
  56. GRB 090518: Enhanced Swift-XRT position
  57. GRB 090518: Swift detection of a burst
  58. GRB 090516: GROND OBSERVATIONS
  59. GRB 090516 - Zadko Telescope observations
  60. GRB 090516: NOT optical observations
  61. GRB 090516: Swift/UVOT Observations
  62. GRB 090516: Enhanced Swift-XRT position
  63. GRB 090516: Swift detection of a burst
  64. GRB 090515: VLA observations
  65. GRB 090515: Lick Upper Limits
  66. GRB 090515: ROVOR Upper Limit
  67. GRB 090515: MMT/MMIRS NIR Upper Limit
  68. GRB 090515: Swift/UVOT Observations
  69. GRB 090515: Enhanced Swift-XRT position
  70. GRB 090509 - Zadko Telescope observations
  71. GRB 090515: Gemini-N upper limit
  72. GRB 090515: WIYN NIR Upper Limit
  73. GRB 090515: Super-LOTIS Upper Limits
  74. GRB 090515: PAIRITEL Upper Limits
  75. GRB 090515: ROTSE-III Optical Limits
  76. GRB 090515: Swift detection of a short burst
  77. GRB 090510: Suzaku WAM observation of the prompt emission
  78. GRB 090510, Radio limits
  79. GRB090510: VLT/FORS2 spectroscopic redshift
  80. GRB 090510: GROND observations
  81. GRB 090509, further Swift-BAT refined analysis
  82. Konus-Wind observation of GRB 090510
  83. AGILE detection of GRB 090510
  84. GRB 090510: UVOT refined analysis
  85. GRB 090510: Enhanced Swift-XRT position
  86. GRB 090510: NOT afterglow confirmation
  87. GRB 090510: Fermi GBM detection
  88. Fermi LAT detection of GRB 090510
  89. GRB 090509, SMARTS optical/IR afterglow observations
  90. GRB 090510: Swift detection of a short hard burst
  91. GRB 090509: GROND further analysis and redshift limit
  92. GRB 090509: REM NIR afterglow
  93. GRB 090509: GROND afterglow candidate
  94. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  95. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  96. GRB 090427: GROND observations
  97. GRB 090429A: ROVOR magnitude limit
  98. GRB 090428B: Suzaku WAM observation of the prompt emission
  99. GRB 090424, SMARTS optical/IR afterglow monitoring
  100. GRB 090429B: Swift/UVOT Upper Limits

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