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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"

27075 results found.

  1. Trigger 626581: Swift detection of GRO J1008-57
  2. The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc
  3. Swift detection of the variable star SZ Psc
  4. GRB 150110C: Swift/UVOT Upper Limits
  5. GRB 150110C: Swift-XRT observations
  6. GRB 150110B: Swift-BAT refined analysis
  7. GRB 150110A: MASTER inspection
  8. GRB 150110B: Swift-XRT refined Analysis
  9. GRB 150110B: Swift/UVOT Upper Limits
  10. GRB 150110B: Fermi GBM Detection
  11. GRB 150110A: Fermi GBM Detection
  12. GRB 150110B: Swift detection of a burst
  13. Fermi GBM trigger 150108121 is not a GRB
  14. Fermi GBM trigger 150106207 is not a GRB
  15. GRB 150105A: Fermi GBM detection
  16. Swift detection of 4U 1700+24 (= V* V934 Her)
  17. GRB 150103A: MASTER optical observations
  18. GRB 150103A: Swift-XRT refined Analysis
  19. GRB 150101B: Fermi GBM detection
  20. GRB 150103A: Swift/UVOT Upper Limits
  21. GRB 150103A: Swift-BAT refined analysis
  22. GRB 150103A: Zadko observatory - Gingin optical observations
  23. Swift J123205.1-105602: Magellan candidate afterglow
  24. GRB 150103A: Swift detection of a burst
  25. Short burst found in ground analysis of Swift-BAT data
  26. GRB 150101A Swift-BAT refined analysis of the short hard burst
  27. GRB 150101A: Fermi GBM detection
  28. GRB 150101A: Swift-XRT refined Analysis
  29. GRB 150101A: Swift/UVOT Upper Limits
  30. GRB 150101A: Swift detection of a short burst
  31. GRB 141229A: Deep MASTER inspection
  32. Swift-XRT and UVOT follow-up of iPTF14jko (GRB 141230A)
  33. GRB 141230A: Fermi GBM detection
  34. GRB 141230A: Nanshan optical obsrvations
  35. GRB 141230A: iPTF Optical Observations and Candidate Afterglow iPTF14jko
  36. GRB 141229A: Swift-XRT observations
  37. Fermi GBM trigger 141229739 is not a GRB
  38. GRB 141229A: Fermi GBM detection
  39. Christmas GRB 141225A: GROND Observations
  40. GRB 141225A: MASTER-SAAO OT light curve
  41. GRB 141225A: TAROT Calern observatory optical observations
  42. GRB 141225A: Swift/UVOT refined analysis
  43. GRB 141225A: Fermi GBM detection
  44. GRB 141225A: very early T60 observations
  45. GRB 141225A: Swift-BAT refined analysis
  46. GRB 141225A: Swift-XRT refined Analysis
  47. GRB 141225A: MASTER-SAAO first OT detection
  48. GRB 141225A: UVOT detection
  49. GRB 141225A: Optical aftergow confirmation
  50. GRB 141225A: LT optical candidate
  51. GRB 141225A: Swift detection of a burst
  52. GRB 141221A: TAROT La Silla observatory optical observations
  53. Swift XRT and UVOT observations of GRB141222A
  54. GRB 141222A: First MASTER-SAAO optical observation
  55. GRB 141221A: Continued Skynet PROMPT-CTIO observations
  56. GRB 141222A: Fermi GBM detection
  57. GRB 141221A: Swift/UVOT Detection
  58. GRB 141222A: Fermi-LAT detection
  59. GRB 141215A: further Swift-XRT observations and afterglow detection
  60. GRB 141221A: Fermi GBM observation
  61. GRB 141221A: Swift-XRT refined Analysis
  62. GRB 141221A: Swift-BAT refined analysis
  63. GRB141221A: GROND Afterglow Detection
  64. GRB 141221A: Skynet PROMPT-CTIO observations of the optical afterglow
  65. GRB 141221A: LCOGT-McDonald optical afterglow observations
  66. Konus-Wind observation of GRB 141220A
  67. GRB 141221A: Swift detection of a burst with an optical counterpart
  68. GRB 141220A: Fermi GBM observation
  69. GRB 141220A: Swift-XRT refined Analysis
  70. GRB 141220A: Swift-BAT refined analysis
  71. GRB 141220A: Swift/UVOT Detection
  72. GRB 141220A: LT optical afterglow observations
  73. GRB 141220A: Swift detection of a burst with an optical afterglow
  74. Fermi Gamma-ray Burst Monitor trigger 440728127 / 141220020 is not a GRB
  75. GRB 141207A: Suzaku WAM observation of the prompt emission
  76. GRB 141202A: Suzaku WAM observation of the prompt emission
  77. GRB 141215A: Swift-XRT observations
  78. GRB 141215A: Fermi GBM detection
  79. IPN Triangulation of GRB 141215A (long/intense)
  80. GRB 141212A iTelescope observation
  81. GRB 141212A: Zadko observatory - Gingin optical observations
  82. Konus-Wind observation of GRB 141212B
  83. GRB 141212B: Swift-XRT refined Analysis
  84. GRB 141212A: Swift/UVOT Upper Limits
  85. GRB 141212B: Swift/UVOT Upper Limits
  86. GRB 141212A: Gemini-N spectroscopy and photometry
  87. GRB 141212B: Swift-BAT refined analysis
  88. GRB 141212A: Swift-BAT refined analysis
  89. Swift detection of 4U 1700+24 (= V934 Her)
  90. GRB 141212A: Swift-XRT refined Analysis
  91. GRB 141212B: initial Swift/UVOT observations
  92. GRB 141212B: Swift/XRT preliminary localization
  93. GRB 141212A: MASTER early optical observations
  94. GRB 141212A: Skynet R-COP Observations
  95. GRB 141212B: Swift detection of a burst
  96. GRB 141212A: Swift detection of a short burst
  97. GRB141208.63: MASTER OT Detection During the Fermi Error Box inspection
  98. GRB141207A: Discovery Channel Telescope Optical Observations
  99. GRB 141207A: Fermi GBM detection
  100. Konus-Wind observation of GRB 141130A

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