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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"

28054 results found.

  1. Konus-Wind observation of GRB 141130A
  2. GRB 141207A: Fermi-LAT Detection
  3. GRB141121A: Discovery Channel Telescope Optical Observations
  4. GRB 141205A: Swift/UVOT Upper Limits
  5. GRB 141205A: Fermi GBM detection
  6. GRB 141205A: Nanshan optical upper limit
  7. GRB 141121A: Mondy optical observations
  8. GRB 141205A Short hard GRB found in ground analysis of BAT data
  9. GRB 141130A: Mondy optical observations
  10. GRB 141202A: Swift XRT observations
  11. GRB 141202A: Fermi GBM Detection
  12. GRB 141030A: Nanshan very early optical observations
  13. GRB 141121A: Continued RATIR Optical Observations
  14. GRB 141130A: Swift-BAT refined analysis
  15. GRB 141130A: Swift/UVOT Detection
  16. GRB 141130A: Swift-XRT refined Analysis
  17. GRB 141130A: Enhanced Swift-XRT position
  18. GRB 141130A: Nanshan optical observations
  19. GRB 141130A: Mondy optical observations
  20. GRB 141130A: Swift detection of a burst with an optical counterpart
  21. GRB 141121A: Continued RATIR Optical Observations
  22. GRB 141121A: Mondy optical observations
  23. GRB 141121A: TSHAO optical observations
  24. GRB 141121A: Continued RATIR Optical Observations
  25. GRB 141121A: MITSuME Ishigakijima Optical Observation after 7 days
  26. GRB 141121A: Khureltogot optical observations
  27. GRB 141121A: Mondy optical observations
  28. GRB 141121A: RATIR Optical and NIR Observations
  29. IPN Triangulation of GRB 141125A (short/hard)
  30. GRB 141121A: three epochs of SAO RAS optical observations
  31. GRB 141121A: Continued RATIR Optical Observations
  32. GRB 141121A: TSHAO optical observations
  33. GRB 141121A: Continued Mondy optical observations
  34. GRB 141121A: Continued RATIR Optical Observations
  35. GRB 141121A: RATIR Optical Observations - Steeper Fading
  36. GRB 141121A: MITSuME Ishigakijima Optical Observation after 3 days
  37. GRB 141124A​: iPTF upper limits​
  38. GRB 141121A: RATIR Optical Observations - Fading Again
  39. GRB141124A: MASTER Detection of New Flare of QSO NVSS J075043+790917 During the Fermi Error Box inspection
  40. GRB 141118A: Fermi GBM Detection
  41. GRB 141121A: Mondy optical observations
  42. GRB 141121A: MITSuME Ishigakijima Optical Observation
  43. GRB 141121A: Continued RATIR Optical Observations - Rebrightening
  44. GRB 141121A: AAO optical observations
  45. GRB 141121A: MITSuME Akeno Optical observation
  46. GRB 141121A: Continued RATIR Optical Observations
  47. GRB 141121A: Swift-XRT refined Analysis
  48. GRB 141121A: Swift/UVOT Detections
  49. GRB 141121A: RATIR Optical Observations
  50. GRB 141121A: Swift-BAT refined analysis
  51. GRB 141121A: Enhanced Swift-XRT position
  52. GRB 141118A: iPTF Optical Observations
  53. GRB 141121A: GROND Afterglow candidate
  54. GRB 141121A: MAXI/GSC detection
  55. GRB 141121A: Swift detection of a burst
  56. IPN Triangulation of GRB 141118A
  57. GRB 141104A: further Swift-XRT observations and afterglow candidate
  58. Swift Trigger 618673: probable noise event
  59. Trigger 618634: Swift detection of Vela X-1
  60. GRB 141109B: optical upper limits
  61. GRB 141015A: TAROT La Silla observatory optical observations
  62. GRB 141022A: TAROT La Silla observatory optical observations
  63. GRB 141031A: TAROT La Silla observatory optical observations
  64. GRB 141109A: TAROT La Silla observatory optical observations
  65. GRB 141109A: AAO optical observations
  66. Swift Trigger 618402: probable noise event
  67. Swift Trigger 618391 is not an astrophysical event
  68. GRB 141109A: Terskol photometry
  69. GRB 141109B: Swift/UVOT Upper Limits
  70. GRB 141109A: Swift/UVOT Detection
  71. GRB 141109A: NOT r-band observation
  72. Konus-Wind observation of GRB 141109A
  73. GRB 141109B: MITSuME Akeno upper limits
  74. GRB 141109B: IRAM 30m millimetre observations
  75. GRB 141109B: Swift-XRT refined Analysis
  76. Swift Trigger 618134 is not an astrophysical event
  77. GRB 141109A: MITSuME Ishigakijima upper limits
  78. GRB 141109A: Swift-XRT refined Analysis
  79. GRB 141109B: Swift-BAT refined analysis
  80. GRB 141109B: Enhanced Swift-XRT position
  81. GRB 141109A: Swift-BAT refined analysis
  82. GRB 141109A: Enhanced Swift-XRT position
  83. GRB 141109A: CQUEAN Detection at 0.85 - 1.05 micron
  84. GRB 141109A: GROND afterglow observation
  85. GRB 141109A: REM NIR candidate afterglow
  86. GRB 141109B: Swift detection of a burst
  87. GRB 141109A: Swift detection of a burst
  88. GRB 141104A: Swift-XRT observations
  89. GRB 141028A: Mondy optical observations
  90. GRB 141026A: CrAO optical observation
  91. GRB
  92. GRB 141028A: TShAO optical observation
  93. GRB 141031B: TShAO optical observations
  94. GRB 141017A: Skynet PROMPT-CTIO/SSO Observations
  95. IPN Triangulation of GRB 141104A (long/very bright)
  96. Konus-Wind observation of GRB 141102A
  97. GRB 141022A: Skynet PROMPT-CTIO Observations
  98. GRB 141102A: Fermi GBM detection
  99. GRB 141031B: RATIR Optical and NIR Observation
  100. GRB 141031B: Swift/UVOT Upper Limits

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