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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"

24167 results found.

  1. GRB 090516B: Fermi GBM detection
  2. GRB 090519B: Fermi GBM detection
  3. GRB 090519: Swift-XRT refined analysis
  4. GRB 090519: GROND observation
  5. GRB 090519: Swift/UVOT Upper Limits
  6. GRB 090519, Swift-BAT refined analysis
  7. GRB 090519: Limits from BOOTES-1B
  8. GRB 090519: FARO Chante Perdrix Observatory optical observations
  9. GRB 090519: TAROT Calern observatory optical observations
  10. GRB 090519: Swift detection of a burst
  11. GRB 090511: Fermi GBM Detection
  12. GRB 090514: Fermi GBM detection
  13. GRB 090518: Swift/UVOT Upper Limits
  14. GRB 090518, Swift-BAT refined analysis
  15. GRB 090518B: Fermi GBM detection
  16. GRB 090516, RIMOTS optical upper limits
  17. GRB090513: Fermi GBM detection
  18. GRB 090518: Swift-XRT refined analysis
  19. GRB 090518: Swift detection of a burst
  20. GRB 090515: Swift/BAT spectral lag results
  21. GRB 090516: Swift-BAT refined analysis
  22. GRB 090516: GROND OBSERVATIONS
  23. GRB 090516 - Zadko Telescope observations
  24. GRB 090516: Swift XRT refined analysis
  25. GRB 090516: Swift/UVOT Observations
  26. GRB 090516: Faulkes Telescope South optical afterglow
  27. GRB 090516: Swift detection of a burst
  28. GRB 090515: Lick Upper Limits
  29. GRB 090515: ROVOR Upper Limit
  30. GRB 090515: MMT/MMIRS NIR Upper Limit
  31. GRB 090515: Swift/UVOT Observations
  32. GRB 090515: Swift-XRT refined analysis
  33. GRB 090509: Fermi GBM observation
  34. GRB 090515: Swift-BAT refined spectral analysis
  35. GRB 090515: Swift-BAT refined analysis
  36. GRB 090509 - Zadko Telescope observations
  37. GRB 090515: WIYN NIR Upper Limit
  38. GRB 090515: Super-LOTIS Upper Limits
  39. GRB 090515: PAIRITEL Upper Limits
  40. GRB 090515: KAIT optical upper limits
  41. GRB 090515: ROTSE-III Optical Limits
  42. GRB 090515: Swift detection of a short burst
  43. GRB 090510: Suzaku WAM observation of the prompt emission
  44. GRB 090510: Swift/UVOT host galaxy candidates
  45. GRB 090510: Fermi-LAT follow-up analysis
  46. GRB 090509, further Swift-BAT refined analysis
  47. Fermi Gamma-ray Burst Monitor trigger 263649437 is not a GRB
  48. GRB 090510B: Fermi GBM detection
  49. GRB 090502: Fermi GBM detection
  50. Konus-Wind observation of GRB 090510
  51. GRB 090510: UVOT refined analysis
  52. GRB 090510: Swift XRT refined analysis
  53. GRB 090510: Swift-BAT refined analysis
  54. GRB 090510: Fermi GBM detection
  55. GRB 090509: Swift-BAT refined analysis
  56. Fermi LAT detection of GRB 090510
  57. GRB 090510: Swift/UVOT Detection of a Candidate Optical Afterglow
  58. GRB 090510: Swift detection of a short hard burst
  59. GRB 090408: optical upper limit
  60. GRB 090509: GROND further analysis and redshift limit
  61. GRB 090509: REM NIR afterglow
  62. GRB 090509: GROND afterglow candidate
  63. GRB 090509: Swift detection of a burst
  64. GRB 090323: optical observations
  65. GRB 090424: optical observations
  66. GRB 090429A: ROVOR magnitude limit
  67. GRB 090428B: Suzaku WAM observation of the prompt emission
  68. GRB 090426: optical observations
  69. GRB 090429D: Fermi GBM detection
  70. GRB 090429C: Fermi GBM detection
  71. GRB 090429B: Swift/UVOT Upper Limits
  72. GRB 090429A: Swift/UVOT Upper Limits
  73. GRB 090424: YNAO-GMG observations
  74. GRB 090429A: GROND upper limits
  75. GRB 090427C: Fermi GBM detection
  76. GRB 090427B: Fermi GBM detection
  77. GRB 090426C: Fermi GBM detection
  78. GRB 090426B: Fermi GBM detection/observation
  79. GRB 090429B: Swift XRT refined analysis
  80. GRB 090428B: Fermi GBM detection
  81. GRB 090428: Fermi GBM detection
  82. GRB 090426: GAO 150cm telescope Optical Observation
  83. GRB 090429B: RIMOTS optical upper limits
  84. GRB 090429B: Swift-BAT refined analysis
  85. GRB 090429A: Swift-BAT refined analysis
  86. GRB 090426: YNAO-GMG observations
  87. GRB 090429B: GROND Observations
  88. GRB 090429B: Super-LOTIS early observations
  89. GRB 090429B: Swift detection of a burst
  90. GRB 090429: Swift detection of a burst
  91. GRB 090423: pseudo burst at z=1 and its relation to GRB 080913
  92. GRB 090426: Swift/BAT spectral lag results
  93. GRB 090425: Fermi GBM detection
  94. GRB 090424: Suzaku WAM observation of the prompt emission
  95. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  96. GRB090426 Swift/UVOT observations
  97. GRB 090426 Keck LRIS redshift
  98. GRB 090426: Swift-BAT refined analysis
  99. GRB 090426: Swift-XRT refined analysis
  100. GRB 090423: GROND second epoch imaging and refined SED

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